Update sqlite to 3.8.0.2. A list of changes are available here:

http://sqlite.org/changes.html. Tested in a bulk and ok landry@ ok espie@
author: jturner <jturner@openbsd.org> 2013-09-21 17:29:17 +0000
committer: jturner <jturner@openbsd.org> 2013-09-21 17:29:17 +0000
commit: 97d5d4b962418e3e648246a809ce03d33b566903 (patch)
tree: 328321c85977b8756ec8d84f6d12e16569cb3fa4 /lib/libsqlite3
parent: regen (diff)
download: wireguard-openbsd-97d5d4b962418e3e648246a809ce03d33b566903.tar.xz
wireguard-openbsd-97d5d4b962418e3e648246a809ce03d33b566903.zip
87 files changed, 5532 insertions, 3428 deletions
diff --git a/lib/libsqlite3/VERSION b/lib/libsqlite3/VERSION
index 9a4c4371ee7..9ad370dd95b 100644
--- a/lib/libsqlite3/VERSION
+++ b/lib/libsqlite3/VERSION
@@ -1 +1 @@
-3.7.17
+3.8.0.2
diff --git a/lib/libsqlite3/ext/fts1/fts1.c b/lib/libsqlite3/ext/fts1/fts1.c
index d5429ff320a..482cf759ba1 100644
--- a/lib/libsqlite3/ext/fts1/fts1.c
+++ b/lib/libsqlite3/ext/fts1/fts1.c
@@ -3335,8 +3335,11 @@ int sqlite3Fts1Init(sqlite3 *db){
 }
 
 #if !SQLITE_CORE
-int sqlite3_extension_init(sqlite3 *db, char **pzErrMsg,
-                           const sqlite3_api_routines *pApi){
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_fts1_init(sqlite3 *db, char **pzErrMsg,
+                      const sqlite3_api_routines *pApi){
   SQLITE_EXTENSION_INIT2(pApi)
   return sqlite3Fts1Init(db);
 }
diff --git a/lib/libsqlite3/ext/fts1/fulltext.c b/lib/libsqlite3/ext/fts1/fulltext.c
index e6034ba0230..313ff303e1a 100644
--- a/lib/libsqlite3/ext/fts1/fulltext.c
+++ b/lib/libsqlite3/ext/fts1/fulltext.c
@@ -852,8 +852,14 @@ static void fulltext_vtab_destroy(fulltext_vtab *v){
 ** argv[3] - tokenizer name (optional, a sensible default is provided)
 ** argv[4..] - passed to tokenizer (optional based on tokenizer)
 **/
-static int fulltextConnect(sqlite3 *db, void *pAux, int argc, char **argv,
-                           sqlite3_vtab **ppVTab){
+static int fulltextConnect(
+  sqlite3 *db,
+  void *pAux,
+  int argc,
+  const char * const *argv,
+  sqlite3_vtab **ppVTab,
+  char **pzErr
+){
   int rc;
   fulltext_vtab *v;
   sqlite3_tokenizer_module *m = NULL;
@@ -898,8 +904,14 @@ static int fulltextConnect(sqlite3 *db, void *pAux, int argc, char **argv,
   return SQLITE_OK;
 }
 
-static int fulltextCreate(sqlite3 *db, void *pAux, int argc, char **argv,
-                          sqlite3_vtab **ppVTab){
+static int fulltextCreate(
+  sqlite3 *db,
+  void *pAux,
+  int argc,
+  const char * const *argv,
+  sqlite3_vtab **ppVTab,
+  char **pzErr
+){
   int rc;
   assert( argc>=3 );
 
@@ -934,7 +946,7 @@ static int fulltextCreate(sqlite3 *db, void *pAux, int argc, char **argv,
     "create index %_index on %_term(term, first)");
   if( rc!=SQLITE_OK ) return rc;
 
-  return fulltextConnect(db, pAux, argc, argv, ppVTab);
+  return fulltextConnect(db, pAux, argc, argv, ppVTab, pzErr);
 }
 
 /* Decide how to handle an SQL query.
@@ -1488,8 +1500,11 @@ int fulltext_init(sqlite3 *db){
 }
 
 #if !SQLITE_CORE
-int sqlite3_extension_init(sqlite3 *db, char **pzErrMsg,
-                           const sqlite3_api_routines *pApi){
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_fulltext_init(sqlite3 *db, char **pzErrMsg,
+                          const sqlite3_api_routines *pApi){
  SQLITE_EXTENSION_INIT2(pApi)
  return fulltext_init(db);
 }
diff --git a/lib/libsqlite3/ext/fts2/fts2.c b/lib/libsqlite3/ext/fts2/fts2.c
index f008ce6dc09..0405fb7b1e5 100644
--- a/lib/libsqlite3/ext/fts2/fts2.c
+++ b/lib/libsqlite3/ext/fts2/fts2.c
@@ -6844,7 +6844,10 @@ int sqlite3Fts2Init(sqlite3 *db){
 }
 
 #if !SQLITE_CORE
-int sqlite3_extension_init(
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_fts2_init(
   sqlite3 *db, 
   char **pzErrMsg,
   const sqlite3_api_routines *pApi
diff --git a/lib/libsqlite3/ext/fts2/fts2_hash.c b/lib/libsqlite3/ext/fts2/fts2_hash.c
index f22fcc91dfa..3596dcf0b80 100644
--- a/lib/libsqlite3/ext/fts2/fts2_hash.c
+++ b/lib/libsqlite3/ext/fts2/fts2_hash.c
@@ -30,6 +30,8 @@
 #include <string.h>
 
 #include "sqlite3.h"
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT3
 #include "fts2_hash.h"
 
 /*
diff --git a/lib/libsqlite3/ext/fts2/fts2_porter.c b/lib/libsqlite3/ext/fts2/fts2_porter.c
index 16620b93535..881baf7100f 100644
--- a/lib/libsqlite3/ext/fts2/fts2_porter.c
+++ b/lib/libsqlite3/ext/fts2/fts2_porter.c
@@ -30,6 +30,9 @@
 #include <stdio.h>
 #include <string.h>
 
+#include "sqlite3.h"
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT3
 #include "fts2_tokenizer.h"
 
 /*
diff --git a/lib/libsqlite3/ext/fts2/fts2_tokenizer.c b/lib/libsqlite3/ext/fts2/fts2_tokenizer.c
index a93790c8011..a3d6a6312a9 100644
--- a/lib/libsqlite3/ext/fts2/fts2_tokenizer.c
+++ b/lib/libsqlite3/ext/fts2/fts2_tokenizer.c
@@ -28,7 +28,7 @@
 
 #include "sqlite3.h"
 #include "sqlite3ext.h"
-SQLITE_EXTENSION_INIT1
+SQLITE_EXTENSION_INIT3
 
 #include "fts2_hash.h"
 #include "fts2_tokenizer.h"
diff --git a/lib/libsqlite3/ext/fts2/fts2_tokenizer1.c b/lib/libsqlite3/ext/fts2/fts2_tokenizer1.c
index 7e13366910d..fe4f9eb4b56 100644
--- a/lib/libsqlite3/ext/fts2/fts2_tokenizer1.c
+++ b/lib/libsqlite3/ext/fts2/fts2_tokenizer1.c
@@ -30,6 +30,9 @@
 #include <stdio.h>
 #include <string.h>
 
+#include "sqlite3.h"
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT3
 #include "fts2_tokenizer.h"
 
 typedef struct simple_tokenizer {
diff --git a/lib/libsqlite3/ext/fts3/fts3.c b/lib/libsqlite3/ext/fts3/fts3.c
index c00a13f5a10..0f7c38e5711 100644
--- a/lib/libsqlite3/ext/fts3/fts3.c
+++ b/lib/libsqlite3/ext/fts3/fts3.c
@@ -1081,6 +1081,8 @@ static int fts3InitVtab(
   char *zUncompress = 0;          /* uncompress=? parameter (or NULL) */
   char *zContent = 0;             /* content=? parameter (or NULL) */
   char *zLanguageid = 0;          /* languageid=? parameter (or NULL) */
+  char **azNotindexed = 0;        /* The set of notindexed= columns */
+  int nNotindexed = 0;            /* Size of azNotindexed[] array */
 
   assert( strlen(argv[0])==4 );
   assert( (sqlite3_strnicmp(argv[0], "fts4", 4)==0 && isFts4)
@@ -1090,9 +1092,19 @@ static int fts3InitVtab(
   nDb = (int)strlen(argv[1]) + 1;
   nName = (int)strlen(argv[2]) + 1;
 
-  aCol = (const char **)sqlite3_malloc(sizeof(const char *) * (argc-2) );
-  if( !aCol ) return SQLITE_NOMEM;
-  memset((void *)aCol, 0, sizeof(const char *) * (argc-2));
+  nByte = sizeof(const char *) * (argc-2);
+  aCol = (const char **)sqlite3_malloc(nByte);
+  if( aCol ){
+    memset((void*)aCol, 0, nByte);
+    azNotindexed = (char **)sqlite3_malloc(nByte);
+  }
+  if( azNotindexed ){
+    memset(azNotindexed, 0, nByte);
+  }
+  if( !aCol || !azNotindexed ){
+    rc = SQLITE_NOMEM;
+    goto fts3_init_out;
+  }
 
   /* Loop through all of the arguments passed by the user to the FTS3/4
   ** module (i.e. all the column names and special arguments). This loop
@@ -1131,7 +1143,8 @@ static int fts3InitVtab(
         { "uncompress", 10 },     /* 3 -> UNCOMPRESS */
         { "order",       5 },     /* 4 -> ORDER */
         { "content",     7 },     /* 5 -> CONTENT */
-        { "languageid", 10 }      /* 6 -> LANGUAGEID */
+        { "languageid", 10 },     /* 6 -> LANGUAGEID */
+        { "notindexed", 10 }      /* 7 -> NOTINDEXED */
       };
 
       int iOpt;
@@ -1197,6 +1210,11 @@ static int fts3InitVtab(
               zLanguageid = zVal;
               zVal = 0;
               break;
+
+            case 7:              /* NOTINDEXED */
+              azNotindexed[nNotindexed++] = zVal;
+              zVal = 0;
+              break;
           }
         }
         sqlite3_free(zVal);
@@ -1268,6 +1286,7 @@ static int fts3InitVtab(
   nByte = sizeof(Fts3Table) +                  /* Fts3Table */
           nCol * sizeof(char *) +              /* azColumn */
           nIndex * sizeof(struct Fts3Index) +  /* aIndex */
+          nCol * sizeof(u8) +                  /* abNotindexed */
           nName +                              /* zName */
           nDb +                                /* zDb */
           nString;                             /* Space for azColumn strings */
@@ -1301,9 +1320,10 @@ static int fts3InitVtab(
   for(i=0; i<nIndex; i++){
     fts3HashInit(&p->aIndex[i].hPending, FTS3_HASH_STRING, 1);
   }
+  p->abNotindexed = (u8 *)&p->aIndex[nIndex];
 
   /* Fill in the zName and zDb fields of the vtab structure. */
-  zCsr = (char *)&p->aIndex[nIndex];
+  zCsr = (char *)&p->abNotindexed[nCol];
   p->zName = zCsr;
   memcpy(zCsr, argv[2], nName);
   zCsr += nName;
@@ -1324,7 +1344,26 @@ static int fts3InitVtab(
     assert( zCsr <= &((char *)p)[nByte] );
   }
 
-  if( (zCompress==0)!=(zUncompress==0) ){
+  /* Fill in the abNotindexed array */
+  for(iCol=0; iCol<nCol; iCol++){
+    int n = (int)strlen(p->azColumn[iCol]);
+    for(i=0; i<nNotindexed; i++){
+      char *zNot = azNotindexed[i];
+      if( zNot && 0==sqlite3_strnicmp(p->azColumn[iCol], zNot, n) ){
+        p->abNotindexed[iCol] = 1;
+        sqlite3_free(zNot);
+        azNotindexed[i] = 0;
+      }
+    }
+  }
+  for(i=0; i<nNotindexed; i++){
+    if( azNotindexed[i] ){
+      *pzErr = sqlite3_mprintf("no such column: %s", azNotindexed[i]);
+      rc = SQLITE_ERROR;
+    }
+  }
+
+  if( rc==SQLITE_OK && (zCompress==0)!=(zUncompress==0) ){
     char const *zMiss = (zCompress==0 ? "compress" : "uncompress");
     rc = SQLITE_ERROR;
     *pzErr = sqlite3_mprintf("missing %s parameter in fts4 constructor", zMiss);
@@ -1365,7 +1404,9 @@ fts3_init_out:
   sqlite3_free(zUncompress);
   sqlite3_free(zContent);
   sqlite3_free(zLanguageid);
+  for(i=0; i<nNotindexed; i++) sqlite3_free(azNotindexed[i]);
   sqlite3_free((void *)aCol);
+  sqlite3_free((void *)azNotindexed);
   if( rc!=SQLITE_OK ){
     if( p ){
       fts3DisconnectMethod((sqlite3_vtab *)p);
@@ -1423,7 +1464,7 @@ static int fts3BestIndexMethod(sqlite3_vtab *pVTab, sqlite3_index_info *pInfo){
   ** strategy is possible.
   */
   pInfo->idxNum = FTS3_FULLSCAN_SEARCH;
-  pInfo->estimatedCost = 500000;
+  pInfo->estimatedCost = 5000000;
   for(i=0; i<pInfo->nConstraint; i++){
     struct sqlite3_index_constraint *pCons = &pInfo->aConstraint[i];
     if( pCons->usable==0 ) continue;
@@ -2984,11 +3025,7 @@ static int fts3FilterMethod(
       return rc;
     }
 
-    rc = sqlite3Fts3ReadLock(p);
-    if( rc!=SQLITE_OK ) return rc;
-
     rc = fts3EvalStart(pCsr);
-
     sqlite3Fts3SegmentsClose(p);
     if( rc!=SQLITE_OK ) return rc;
     pCsr->pNextId = pCsr->aDoclist;
@@ -5339,7 +5376,10 @@ int sqlite3Fts3Corrupt(){
 /*
 ** Initialize API pointer table, if required.
 */
-int sqlite3_extension_init(
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_fts3_init(
   sqlite3 *db, 
   char **pzErrMsg,
   const sqlite3_api_routines *pApi
diff --git a/lib/libsqlite3/ext/fts3/fts3Int.h b/lib/libsqlite3/ext/fts3/fts3Int.h
index b19064cd3ba..f399d890389 100644
--- a/lib/libsqlite3/ext/fts3/fts3Int.h
+++ b/lib/libsqlite3/ext/fts3/fts3Int.h
@@ -32,7 +32,7 @@
 /* If not building as part of the core, include sqlite3ext.h. */
 #ifndef SQLITE_CORE
 # include "sqlite3ext.h" 
-extern const sqlite3_api_routines *sqlite3_api;
+SQLITE_EXTENSION_INIT3
 #endif
 
 #include "sqlite3.h"
@@ -40,6 +40,18 @@ extern const sqlite3_api_routines *sqlite3_api;
 #include "fts3_hash.h"
 
 /*
+** This constant determines the maximum depth of an FTS expression tree
+** that the library will create and use. FTS uses recursion to perform 
+** various operations on the query tree, so the disadvantage of a large
+** limit is that it may allow very large queries to use large amounts
+** of stack space (perhaps causing a stack overflow).
+*/
+#ifndef SQLITE_FTS3_MAX_EXPR_DEPTH
+# define SQLITE_FTS3_MAX_EXPR_DEPTH 12
+#endif
+
+
+/*
 ** This constant controls how often segments are merged. Once there are
 ** FTS3_MERGE_COUNT segments of level N, they are merged into a single
 ** segment of level N+1.
@@ -194,6 +206,7 @@ struct Fts3Table {
   const char *zName;              /* virtual table name */
   int nColumn;                    /* number of named columns in virtual table */
   char **azColumn;                /* column names.  malloced */
+  u8 *abNotindexed;               /* True for 'notindexed' columns */
   sqlite3_tokenizer *pTokenizer;  /* tokenizer for inserts and queries */
   char *zContentTbl;              /* content=xxx option, or NULL */
   char *zLanguageid;              /* languageid=xxx option, or NULL */
@@ -421,7 +434,6 @@ int sqlite3Fts3SegReaderPending(
   Fts3Table*,int,const char*,int,int,Fts3SegReader**);
 void sqlite3Fts3SegReaderFree(Fts3SegReader *);
 int sqlite3Fts3AllSegdirs(Fts3Table*, int, int, int, sqlite3_stmt **);
-int sqlite3Fts3ReadLock(Fts3Table *);
 int sqlite3Fts3ReadBlock(Fts3Table*, sqlite3_int64, char **, int*, int*);
 
 int sqlite3Fts3SelectDoctotal(Fts3Table *, sqlite3_stmt **);
diff --git a/lib/libsqlite3/ext/fts3/fts3_expr.c b/lib/libsqlite3/ext/fts3/fts3_expr.c
index c046d7d5ffc..29fb2887dab 100644
--- a/lib/libsqlite3/ext/fts3/fts3_expr.c
+++ b/lib/libsqlite3/ext/fts3/fts3_expr.c
@@ -1000,17 +1000,16 @@ int sqlite3Fts3ExprParse(
   Fts3Expr **ppExpr,                  /* OUT: Parsed query structure */
   char **pzErr                        /* OUT: Error message (sqlite3_malloc) */
 ){
-  static const int MAX_EXPR_DEPTH = 12;
   int rc = fts3ExprParseUnbalanced(
       pTokenizer, iLangid, azCol, bFts4, nCol, iDefaultCol, z, n, ppExpr
   );
   
   /* Rebalance the expression. And check that its depth does not exceed
-  ** MAX_EXPR_DEPTH.  */
+  ** SQLITE_FTS3_MAX_EXPR_DEPTH.  */
   if( rc==SQLITE_OK && *ppExpr ){
-    rc = fts3ExprBalance(ppExpr, MAX_EXPR_DEPTH);
+    rc = fts3ExprBalance(ppExpr, SQLITE_FTS3_MAX_EXPR_DEPTH);
     if( rc==SQLITE_OK ){
-      rc = fts3ExprCheckDepth(*ppExpr, MAX_EXPR_DEPTH);
+      rc = fts3ExprCheckDepth(*ppExpr, SQLITE_FTS3_MAX_EXPR_DEPTH);
     }
   }
 
@@ -1019,7 +1018,8 @@ int sqlite3Fts3ExprParse(
     *ppExpr = 0;
     if( rc==SQLITE_TOOBIG ){
       *pzErr = sqlite3_mprintf(
-          "FTS expression tree is too large (maximum depth %d)", MAX_EXPR_DEPTH
+          "FTS expression tree is too large (maximum depth %d)", 
+          SQLITE_FTS3_MAX_EXPR_DEPTH
       );
       rc = SQLITE_ERROR;
     }else if( rc==SQLITE_ERROR ){
diff --git a/lib/libsqlite3/ext/fts3/fts3_snippet.c b/lib/libsqlite3/ext/fts3/fts3_snippet.c
index d54a7875ea9..3e62799bb75 100644
--- a/lib/libsqlite3/ext/fts3/fts3_snippet.c
+++ b/lib/libsqlite3/ext/fts3/fts3_snippet.c
@@ -504,6 +504,7 @@ static int fts3StringAppend(
     pStr->z = zNew;
     pStr->nAlloc = nAlloc;
   }
+  assert( pStr->z!=0 && (pStr->nAlloc >= pStr->n+nAppend+1) );
 
   /* Append the data to the string buffer. */
   memcpy(&pStr->z[pStr->n], zAppend, nAppend);
diff --git a/lib/libsqlite3/ext/fts3/fts3_unicode2.c b/lib/libsqlite3/ext/fts3/fts3_unicode2.c
index 3c24569026e..fba688ff9ce 100644
--- a/lib/libsqlite3/ext/fts3/fts3_unicode2.c
+++ b/lib/libsqlite3/ext/fts3/fts3_unicode2.c
@@ -101,28 +101,27 @@ int sqlite3FtsUnicodeIsalnum(int c){
     0x02A97004, 0x02A9DC03, 0x02A9EC01, 0x02AAC001, 0x02AAC803,
     0x02AADC02, 0x02AAF802, 0x02AB0401, 0x02AB7802, 0x02ABAC07,
     0x02ABD402, 0x02AF8C0B, 0x03600001, 0x036DFC02, 0x036FFC02,
-    0x037FFC02, 0x03E3FC01, 0x03EC7801, 0x03ECA401, 0x03EEC810,
-    0x03F4F802, 0x03F7F002, 0x03F8001A, 0x03F88007, 0x03F8C023,
-    0x03F95013, 0x03F9A004, 0x03FBFC01, 0x03FC040F, 0x03FC6807,
-    0x03FCEC06, 0x03FD6C0B, 0x03FF8007, 0x03FFA007, 0x03FFE405,
-    0x04040003, 0x0404DC09, 0x0405E411, 0x0406400C, 0x0407402E,
-    0x040E7C01, 0x040F4001, 0x04215C01, 0x04247C01, 0x0424FC01,
-    0x04280403, 0x04281402, 0x04283004, 0x0428E003, 0x0428FC01,
-    0x04294009, 0x0429FC01, 0x042CE407, 0x04400003, 0x0440E016,
-    0x04420003, 0x0442C012, 0x04440003, 0x04449C0E, 0x04450004,
-    0x04460003, 0x0446CC0E, 0x04471404, 0x045AAC0D, 0x0491C004,
-    0x05BD442E, 0x05BE3C04, 0x074000F6, 0x07440027, 0x0744A4B5,
-    0x07480046, 0x074C0057, 0x075B0401, 0x075B6C01, 0x075BEC01,
-    0x075C5401, 0x075CD401, 0x075D3C01, 0x075DBC01, 0x075E2401,
-    0x075EA401, 0x075F0C01, 0x07BBC002, 0x07C0002C, 0x07C0C064,
-    0x07C2800F, 0x07C2C40E, 0x07C3040F, 0x07C3440F, 0x07C4401F,
-    0x07C4C03C, 0x07C5C02B, 0x07C7981D, 0x07C8402B, 0x07C90009,
-    0x07C94002, 0x07CC0021, 0x07CCC006, 0x07CCDC46, 0x07CE0014,
-    0x07CE8025, 0x07CF1805, 0x07CF8011, 0x07D0003F, 0x07D10001,
-    0x07D108B6, 0x07D3E404, 0x07D4003E, 0x07D50004, 0x07D54018,
-    0x07D7EC46, 0x07D9140B, 0x07DA0046, 0x07DC0074, 0x38000401,
-    0x38008060, 0x380400F0, 0x3C000001, 0x3FFFF401, 0x40000001,
-    0x43FFF401,
+    0x037FFC01, 0x03EC7801, 0x03ECA401, 0x03EEC810, 0x03F4F802,
+    0x03F7F002, 0x03F8001A, 0x03F88007, 0x03F8C023, 0x03F95013,
+    0x03F9A004, 0x03FBFC01, 0x03FC040F, 0x03FC6807, 0x03FCEC06,
+    0x03FD6C0B, 0x03FF8007, 0x03FFA007, 0x03FFE405, 0x04040003,
+    0x0404DC09, 0x0405E411, 0x0406400C, 0x0407402E, 0x040E7C01,
+    0x040F4001, 0x04215C01, 0x04247C01, 0x0424FC01, 0x04280403,
+    0x04281402, 0x04283004, 0x0428E003, 0x0428FC01, 0x04294009,
+    0x0429FC01, 0x042CE407, 0x04400003, 0x0440E016, 0x04420003,
+    0x0442C012, 0x04440003, 0x04449C0E, 0x04450004, 0x04460003,
+    0x0446CC0E, 0x04471404, 0x045AAC0D, 0x0491C004, 0x05BD442E,
+    0x05BE3C04, 0x074000F6, 0x07440027, 0x0744A4B5, 0x07480046,
+    0x074C0057, 0x075B0401, 0x075B6C01, 0x075BEC01, 0x075C5401,
+    0x075CD401, 0x075D3C01, 0x075DBC01, 0x075E2401, 0x075EA401,
+    0x075F0C01, 0x07BBC002, 0x07C0002C, 0x07C0C064, 0x07C2800F,
+    0x07C2C40E, 0x07C3040F, 0x07C3440F, 0x07C4401F, 0x07C4C03C,
+    0x07C5C02B, 0x07C7981D, 0x07C8402B, 0x07C90009, 0x07C94002,
+    0x07CC0021, 0x07CCC006, 0x07CCDC46, 0x07CE0014, 0x07CE8025,
+    0x07CF1805, 0x07CF8011, 0x07D0003F, 0x07D10001, 0x07D108B6,
+    0x07D3E404, 0x07D4003E, 0x07D50004, 0x07D54018, 0x07D7EC46,
+    0x07D9140B, 0x07DA0046, 0x07DC0074, 0x38000401, 0x38008060,
+    0x380400F0,
   };
   static const unsigned int aAscii[4] = {
     0xFFFFFFFF, 0xFC00FFFF, 0xF8000001, 0xF8000001,
diff --git a/lib/libsqlite3/ext/fts3/fts3_write.c b/lib/libsqlite3/ext/fts3/fts3_write.c
index 269d1dd5993..cb1d1cb2666 100644
--- a/lib/libsqlite3/ext/fts3/fts3_write.c
+++ b/lib/libsqlite3/ext/fts3/fts3_write.c
@@ -489,37 +489,30 @@ static void fts3SqlExec(
 
 
 /*
-** This function ensures that the caller has obtained a shared-cache
-** table-lock on the %_content table. This is required before reading
-** data from the fts3 table. If this lock is not acquired first, then
-** the caller may end up holding read-locks on the %_segments and %_segdir
-** tables, but no read-lock on the %_content table. If this happens 
-** a second connection will be able to write to the fts3 table, but
-** attempting to commit those writes might return SQLITE_LOCKED or
-** SQLITE_LOCKED_SHAREDCACHE (because the commit attempts to obtain 
-** write-locks on the %_segments and %_segdir ** tables). 
+** This function ensures that the caller has obtained an exclusive 
+** shared-cache table-lock on the %_segdir table. This is required before 
+** writing data to the fts3 table. If this lock is not acquired first, then
+** the caller may end up attempting to take this lock as part of committing
+** a transaction, causing SQLite to return SQLITE_LOCKED or 
+** LOCKED_SHAREDCACHEto a COMMIT command.
 **
-** We try to avoid this because if FTS3 returns any error when committing
-** a transaction, the whole transaction will be rolled back. And this is
-** not what users expect when they get SQLITE_LOCKED_SHAREDCACHE. It can
-** still happen if the user reads data directly from the %_segments or
-** %_segdir tables instead of going through FTS3 though.
-**
-** This reasoning does not apply to a content=xxx table.
+** It is best to avoid this because if FTS3 returns any error when 
+** committing a transaction, the whole transaction will be rolled back. 
+** And this is not what users expect when they get SQLITE_LOCKED_SHAREDCACHE. 
+** It can still happen if the user locks the underlying tables directly 
+** instead of accessing them via FTS.
 */
-int sqlite3Fts3ReadLock(Fts3Table *p){
-  int rc;                         /* Return code */
-  sqlite3_stmt *pStmt;            /* Statement used to obtain lock */
-
-  if( p->zContentTbl==0 ){
-    rc = fts3SqlStmt(p, SQL_SELECT_CONTENT_BY_ROWID, &pStmt, 0);
+static int fts3Writelock(Fts3Table *p){
+  int rc = SQLITE_OK;
+  
+  if( p->nPendingData==0 ){
+    sqlite3_stmt *pStmt;
+    rc = fts3SqlStmt(p, SQL_DELETE_SEGDIR_LEVEL, &pStmt, 0);
     if( rc==SQLITE_OK ){
       sqlite3_bind_null(pStmt, 1);
       sqlite3_step(pStmt);
       rc = sqlite3_reset(pStmt);
     }
-  }else{
-    rc = SQLITE_OK;
   }
 
   return rc;
@@ -907,12 +900,15 @@ static int fts3InsertTerms(
 ){
   int i;                          /* Iterator variable */
   for(i=2; i<p->nColumn+2; i++){
-    const char *zText = (const char *)sqlite3_value_text(apVal[i]);
-    int rc = fts3PendingTermsAdd(p, iLangid, zText, i-2, &aSz[i-2]);
-    if( rc!=SQLITE_OK ){
-      return rc;
+    int iCol = i-2;
+    if( p->abNotindexed[iCol]==0 ){
+      const char *zText = (const char *)sqlite3_value_text(apVal[i]);
+      int rc = fts3PendingTermsAdd(p, iLangid, zText, iCol, &aSz[iCol]);
+      if( rc!=SQLITE_OK ){
+        return rc;
+      }
+      aSz[p->nColumn] += sqlite3_value_bytes(apVal[i]);
     }
-    aSz[p->nColumn] += sqlite3_value_bytes(apVal[i]);
   }
   return SQLITE_OK;
 }
@@ -1059,9 +1055,12 @@ static void fts3DeleteTerms(
       int iLangid = langidFromSelect(p, pSelect);
       rc = fts3PendingTermsDocid(p, iLangid, sqlite3_column_int64(pSelect, 0));
       for(i=1; rc==SQLITE_OK && i<=p->nColumn; i++){
-        const char *zText = (const char *)sqlite3_column_text(pSelect, i);
-        rc = fts3PendingTermsAdd(p, iLangid, zText, -1, &aSz[i-1]);
-        aSz[p->nColumn] += sqlite3_column_bytes(pSelect, i);
+        int iCol = i-1;
+        if( p->abNotindexed[iCol]==0 ){
+          const char *zText = (const char *)sqlite3_column_text(pSelect, i);
+          rc = fts3PendingTermsAdd(p, iLangid, zText, -1, &aSz[iCol]);
+          aSz[p->nColumn] += sqlite3_column_bytes(pSelect, i);
+        }
       }
       if( rc!=SQLITE_OK ){
         sqlite3_reset(pSelect);
@@ -1462,7 +1461,7 @@ static int fts3SegReaderNextDocid(
       /* The following line of code (and the "p++" below the while() loop) is
       ** normally all that is required to move pointer p to the desired 
       ** position. The exception is if this node is being loaded from disk
-      ** incrementally and pointer "p" now points to the first byte passed
+      ** incrementally and pointer "p" now points to the first byte past
       ** the populated part of pReader->aNode[].
       */
       while( *p | c ) c = *p++ & 0x80;
@@ -2849,8 +2848,8 @@ int sqlite3Fts3SegReaderStep(
       fts3SegReaderSort(apSegment, nMerge, nMerge, xCmp);
       while( apSegment[0]->pOffsetList ){
         int j;                    /* Number of segments that share a docid */
-        char *pList;
-        int nList;
+        char *pList = 0;
+        int nList = 0;
         int nByte;
         sqlite3_int64 iDocid = apSegment[0]->iDocid;
         fts3SegReaderNextDocid(p, apSegment[0], &pList, &nList);
@@ -3303,9 +3302,11 @@ static int fts3DoRebuild(Fts3Table *p){
       rc = fts3PendingTermsDocid(p, iLangid, sqlite3_column_int64(pStmt, 0));
       memset(aSz, 0, sizeof(aSz[0]) * (p->nColumn+1));
       for(iCol=0; rc==SQLITE_OK && iCol<p->nColumn; iCol++){
-        const char *z = (const char *) sqlite3_column_text(pStmt, iCol+1);
-        rc = fts3PendingTermsAdd(p, iLangid, z, iCol, &aSz[iCol]);
-        aSz[p->nColumn] += sqlite3_column_bytes(pStmt, iCol+1);
+        if( p->abNotindexed[iCol]==0 ){
+          const char *z = (const char *) sqlite3_column_text(pStmt, iCol+1);
+          rc = fts3PendingTermsAdd(p, iLangid, z, iCol, &aSz[iCol]);
+          aSz[p->nColumn] += sqlite3_column_bytes(pStmt, iCol+1);
+        }
       }
       if( p->bHasDocsize ){
         fts3InsertDocsize(&rc, p, aSz);
@@ -5108,32 +5109,34 @@ int sqlite3Fts3CacheDeferredDoclists(Fts3Cursor *pCsr){
     iDocid = sqlite3_column_int64(pCsr->pStmt, 0);
   
     for(i=0; i<p->nColumn && rc==SQLITE_OK; i++){
-      const char *zText = (const char *)sqlite3_column_text(pCsr->pStmt, i+1);
-      sqlite3_tokenizer_cursor *pTC = 0;
-  
-      rc = sqlite3Fts3OpenTokenizer(pT, pCsr->iLangid, zText, -1, &pTC);
-      while( rc==SQLITE_OK ){
-        char const *zToken;       /* Buffer containing token */
-        int nToken = 0;           /* Number of bytes in token */
-        int iDum1 = 0, iDum2 = 0; /* Dummy variables */
-        int iPos = 0;             /* Position of token in zText */
-  
-        rc = pModule->xNext(pTC, &zToken, &nToken, &iDum1, &iDum2, &iPos);
-        for(pDef=pCsr->pDeferred; pDef && rc==SQLITE_OK; pDef=pDef->pNext){
-          Fts3PhraseToken *pPT = pDef->pToken;
-          if( (pDef->iCol>=p->nColumn || pDef->iCol==i)
-           && (pPT->bFirst==0 || iPos==0)
-           && (pPT->n==nToken || (pPT->isPrefix && pPT->n<nToken))
-           && (0==memcmp(zToken, pPT->z, pPT->n))
-          ){
-            fts3PendingListAppend(&pDef->pList, iDocid, i, iPos, &rc);
+      if( p->abNotindexed[i]==0 ){
+        const char *zText = (const char *)sqlite3_column_text(pCsr->pStmt, i+1);
+        sqlite3_tokenizer_cursor *pTC = 0;
+
+        rc = sqlite3Fts3OpenTokenizer(pT, pCsr->iLangid, zText, -1, &pTC);
+        while( rc==SQLITE_OK ){
+          char const *zToken;       /* Buffer containing token */
+          int nToken = 0;           /* Number of bytes in token */
+          int iDum1 = 0, iDum2 = 0; /* Dummy variables */
+          int iPos = 0;             /* Position of token in zText */
+
+          rc = pModule->xNext(pTC, &zToken, &nToken, &iDum1, &iDum2, &iPos);
+          for(pDef=pCsr->pDeferred; pDef && rc==SQLITE_OK; pDef=pDef->pNext){
+            Fts3PhraseToken *pPT = pDef->pToken;
+            if( (pDef->iCol>=p->nColumn || pDef->iCol==i)
+                && (pPT->bFirst==0 || iPos==0)
+                && (pPT->n==nToken || (pPT->isPrefix && pPT->n<nToken))
+                && (0==memcmp(zToken, pPT->z, pPT->n))
+              ){
+              fts3PendingListAppend(&pDef->pList, iDocid, i, iPos, &rc);
+            }
           }
         }
+        if( pTC ) pModule->xClose(pTC);
+        if( rc==SQLITE_DONE ) rc = SQLITE_OK;
       }
-      if( pTC ) pModule->xClose(pTC);
-      if( rc==SQLITE_DONE ) rc = SQLITE_OK;
     }
-  
+
     for(pDef=pCsr->pDeferred; pDef && rc==SQLITE_OK; pDef=pDef->pNext){
       if( pDef->pList ){
         rc = fts3PendingListAppendVarint(&pDef->pList, 0);
@@ -5297,6 +5300,9 @@ int sqlite3Fts3UpdateMethod(
   aSzIns = &aSzDel[p->nColumn+1];
   memset(aSzDel, 0, sizeof(aSzDel[0])*(p->nColumn+1)*2);
 
+  rc = fts3Writelock(p);
+  if( rc!=SQLITE_OK ) goto update_out;
+
   /* If this is an INSERT operation, or an UPDATE that modifies the rowid
   ** value, then this operation requires constraint handling.
   **
diff --git a/lib/libsqlite3/ext/fts3/unicode/mkunicode.tcl b/lib/libsqlite3/ext/fts3/unicode/mkunicode.tcl
index 0d58e8aa5c0..2da17c51a53 100644
--- a/lib/libsqlite3/ext/fts3/unicode/mkunicode.tcl
+++ b/lib/libsqlite3/ext/fts3/unicode/mkunicode.tcl
@@ -239,7 +239,10 @@ proc an_load_unicodedata_text {zName} {
     foreach $lField $fields {}
 
     set iCode [expr "0x$code"]
-    set bAlnum [expr {[lsearch {L N} [string range $general_category 0 0]]>=0}]
+    set bAlnum [expr {
+         [lsearch {L N} [string range $general_category 0 0]] >= 0
+      || $general_category=="Co"
+    }]
 
     if { !$bAlnum } { lappend lRet $iCode }
   }
@@ -360,7 +363,7 @@ proc print_isalnum {zFunc lRange} {
     }
     assert( aEntry[0]<key );
     assert( key>=aEntry[iRes] );
-    return (c >= ((aEntry[iRes]>>10) + (aEntry[iRes]&0x3FF)));
+    return (((unsigned int)c) >= ((aEntry[iRes]>>10) + (aEntry[iRes]&0x3FF)));
   }
   return 1;}
   puts "\}"
@@ -729,7 +732,7 @@ proc print_fileheader {} {
 */
   }]
   puts ""
-  puts "#if !defined(SQLITE_DISABLE_FTS3_UNICODE)"
+  puts "#if defined(SQLITE_ENABLE_FTS4_UNICODE61)"
   puts "#if defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4)"
   puts ""
   puts "#include <assert.h>"
@@ -805,4 +808,4 @@ if {$::generate_test_code} {
 }
 
 puts "#endif /* defined(SQLITE_ENABLE_FTS3) || defined(SQLITE_ENABLE_FTS4) */"
-puts "#endif /* !defined(SQLITE_DISABLE_FTS3_UNICODE) */"
+puts "#endif /* !defined(SQLITE_ENABLE_FTS4_UNICODE61) */"
diff --git a/lib/libsqlite3/ext/icu/icu.c b/lib/libsqlite3/ext/icu/icu.c
index 6a766595066..7cc79b21d00 100644
--- a/lib/libsqlite3/ext/icu/icu.c
+++ b/lib/libsqlite3/ext/icu/icu.c
@@ -9,7 +9,7 @@
 **    May you share freely, never taking more than you give.
 **
 *************************************************************************
-** $Id: icu.c,v 1.1.1.1 2012/04/14 13:13:19 espie Exp $
+** $Id: icu.c,v 1.1.1.2 2013/09/21 17:29:28 jturner Exp $
 **
 ** This file implements an integration between the ICU library 
 ** ("International Components for Unicode", an open-source library 
@@ -22,7 +22,7 @@
 **   * Implementations of the SQL scalar upper() and lower() functions
 **     for case mapping.
 **
-**   * Integration of ICU and SQLite collation seqences.
+**   * Integration of ICU and SQLite collation sequences.
 **
 **   * An implementation of the LIKE operator that uses ICU to 
 **     provide case-independent matching.
@@ -488,7 +488,10 @@ int sqlite3IcuInit(sqlite3 *db){
 }
 
 #if !SQLITE_CORE
-int sqlite3_extension_init(
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_icu_init(
   sqlite3 *db, 
   char **pzErrMsg,
   const sqlite3_api_routines *pApi
diff --git a/lib/libsqlite3/ext/misc/closure.c b/lib/libsqlite3/ext/misc/closure.c
index 213b7633e68..30c812d2201 100644
--- a/lib/libsqlite3/ext/misc/closure.c
+++ b/lib/libsqlite3/ext/misc/closure.c
@@ -496,7 +496,7 @@ static const char *closureValueOfKey(const char *zKey, const char *zStr){
 /*
 ** xConnect/xCreate method for the closure module. Arguments are:
 **
-**   argv[0]    -> module name  ("approximate_match")
+**   argv[0]    -> module name  ("transitive_closure")
 **   argv[1]    -> database name
 **   argv[2]    -> table name
 **   argv[3...] -> arguments
@@ -826,11 +826,17 @@ static int closureBestIndex(
   int iPlan = 0;
   int i;
   int idx = 1;
+  int seenMatch = 0;
   const struct sqlite3_index_constraint *pConstraint;
   closure_vtab *pVtab = (closure_vtab*)pTab;
+  double rCost = 10000000.0;
 
   pConstraint = pIdxInfo->aConstraint;
   for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
+    if( pConstraint->iColumn==CLOSURE_COL_ROOT
+     && pConstraint->op==SQLITE_INDEX_CONSTRAINT_EQ ){
+      seenMatch = 1;
+    }
     if( pConstraint->usable==0 ) continue;
     if( (iPlan & 1)==0 
      && pConstraint->iColumn==CLOSURE_COL_ROOT
@@ -839,6 +845,7 @@ static int closureBestIndex(
       iPlan |= 1;
       pIdxInfo->aConstraintUsage[i].argvIndex = 1;
       pIdxInfo->aConstraintUsage[i].omit = 1;
+      rCost /= 100.0;
     }
     if( (iPlan & 0x0000f0)==0
      && pConstraint->iColumn==CLOSURE_COL_DEPTH
@@ -849,6 +856,7 @@ static int closureBestIndex(
       iPlan |= idx<<4;
       pIdxInfo->aConstraintUsage[i].argvIndex = ++idx;
       if( pConstraint->op==SQLITE_INDEX_CONSTRAINT_LT ) iPlan |= 0x000002;
+      rCost /= 5.0;
     }
     if( (iPlan & 0x000f00)==0
      && pConstraint->iColumn==CLOSURE_COL_TABLENAME
@@ -857,6 +865,7 @@ static int closureBestIndex(
       iPlan |= idx<<8;
       pIdxInfo->aConstraintUsage[i].argvIndex = ++idx;
       pIdxInfo->aConstraintUsage[i].omit = 1;
+      rCost /= 5.0;
     }
     if( (iPlan & 0x00f000)==0
      && pConstraint->iColumn==CLOSURE_COL_IDCOLUMN
@@ -891,13 +900,14 @@ static int closureBestIndex(
   ){
     pIdxInfo->orderByConsumed = 1;
   }
-  pIdxInfo->estimatedCost = (double)10000;
+  if( seenMatch && (iPlan&1)==0 ) rCost *= 1e30;
+  pIdxInfo->estimatedCost = rCost;
    
   return SQLITE_OK;
 }
 
 /*
-** A virtual table module that implements the "approximate_match".
+** A virtual table module that implements the "transitive_closure".
 */
 static sqlite3_module closureModule = {
   0,                      /* iVersion */
diff --git a/lib/libsqlite3/ext/misc/fuzzer.c b/lib/libsqlite3/ext/misc/fuzzer.c
index 642b8f9e92d..fe41cda8c24 100644
--- a/lib/libsqlite3/ext/misc/fuzzer.c
+++ b/lib/libsqlite3/ext/misc/fuzzer.c
@@ -1077,9 +1077,16 @@ static int fuzzerBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
   int iDistTerm = -1;
   int iRulesetTerm = -1;
   int i;
+  int seenMatch = 0;
   const struct sqlite3_index_constraint *pConstraint;
+  double rCost = 1e12;
+
   pConstraint = pIdxInfo->aConstraint;
   for(i=0; i<pIdxInfo->nConstraint; i++, pConstraint++){
+    if( pConstraint->iColumn==0
+     && pConstraint->op==SQLITE_INDEX_CONSTRAINT_MATCH ){
+      seenMatch = 1;
+    }
     if( pConstraint->usable==0 ) continue;
     if( (iPlan & 1)==0 
      && pConstraint->iColumn==0
@@ -1088,6 +1095,7 @@ static int fuzzerBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
       iPlan |= 1;
       pIdxInfo->aConstraintUsage[i].argvIndex = 1;
       pIdxInfo->aConstraintUsage[i].omit = 1;
+      rCost /= 1e6;
     }
     if( (iPlan & 2)==0
      && pConstraint->iColumn==1
@@ -1096,6 +1104,7 @@ static int fuzzerBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
     ){
       iPlan |= 2;
       iDistTerm = i;
+      rCost /= 10.0;
     }
     if( (iPlan & 4)==0
      && pConstraint->iColumn==2
@@ -1104,6 +1113,7 @@ static int fuzzerBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
       iPlan |= 4;
       pIdxInfo->aConstraintUsage[i].omit = 1;
       iRulesetTerm = i;
+      rCost /= 10.0;
     }
   }
   if( iPlan & 2 ){
@@ -1122,7 +1132,8 @@ static int fuzzerBestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
   ){
     pIdxInfo->orderByConsumed = 1;
   }
-  pIdxInfo->estimatedCost = (double)10000;
+  if( seenMatch && (iPlan&1)==0 ) rCost = 1e99;
+  pIdxInfo->estimatedCost = rCost;
    
   return SQLITE_OK;
 }
diff --git a/lib/libsqlite3/ext/misc/ieee754.c b/lib/libsqlite3/ext/misc/ieee754.c
index 436b11e0c53..f1438938857 100644
--- a/lib/libsqlite3/ext/misc/ieee754.c
+++ b/lib/libsqlite3/ext/misc/ieee754.c
@@ -18,11 +18,11 @@
 **
 ** In the first form, the value X should be a floating-point number.
 ** The function will return a string of the form 'ieee754(Y,Z)' where
-** Y and Z are integers such that X==Y*pow(w.0,Z).
+** Y and Z are integers such that X==Y*pow(2,Z).
 **
 ** In the second form, Y and Z are integers which are the mantissa and
 ** base-2 exponent of a new floating point number.  The function returns
-** a floating-point value equal to Y*pow(2.0,Z).
+** a floating-point value equal to Y*pow(2,Z).
 **
 ** Examples:
 **
diff --git a/lib/libsqlite3/ext/misc/nextchar.c b/lib/libsqlite3/ext/misc/nextchar.c
index e063043e04a..6dcbd2dbc31 100644
--- a/lib/libsqlite3/ext/misc/nextchar.c
+++ b/lib/libsqlite3/ext/misc/nextchar.c
@@ -10,12 +10,22 @@
 **
 ******************************************************************************
 **
-** This file contains code to implement the next_char(A,T,F,W) SQL function.
+** This file contains code to implement the next_char(A,T,F,W,C) SQL function.
 **
-** The next_char(A,T,F,H) function finds all valid "next" characters for
-** string A given the vocabulary in T.F.  The T.F field should be indexed.
-** If the W value exists and is a non-empty string, then it is an SQL
-** expression that limits the entries in T.F that will be considered.
+** The next_char(A,T,F,W,C) function finds all valid "next" characters for
+** string A given the vocabulary in T.F.  If the W value exists and is a
+** non-empty string, then it is an SQL expression that limits the entries
+** in T.F that will be considered.  If C exists and is a non-empty string,
+** then it is the name of the collating sequence to use for comparison.  If
+** 
+** Only the first three arguments are required.  If the C parameter is 
+** omitted or is NULL or is an empty string, then the default collating 
+** sequence of T.F is used for comparision.  If the W parameter is omitted
+** or is NULL or is an empty string, then no filtering of the output is
+** done.
+**
+** The T.F column should be indexed using collation C or else this routine
+** will be quite slow.
 **
 ** For example, suppose an application has a dictionary like this:
 **
@@ -184,6 +194,9 @@ static void nextCharFunc(
   const unsigned char *zTable = sqlite3_value_text(argv[1]);
   const unsigned char *zField = sqlite3_value_text(argv[2]);
   const unsigned char *zWhere;
+  const unsigned char *zCollName;
+  char *zWhereClause = 0;
+  char *zColl = 0;
   char *zSql;
   int rc;
 
@@ -192,25 +205,41 @@ static void nextCharFunc(
   c.zPrefix = sqlite3_value_text(argv[0]);
   c.nPrefix = sqlite3_value_bytes(argv[0]);
   if( zTable==0 || zField==0 || c.zPrefix==0 ) return;
-  if( argc<4
-   || (zWhere = sqlite3_value_text(argv[3]))==0
-   || zWhere[0]==0
+  if( argc>=4
+   && (zWhere = sqlite3_value_text(argv[3]))!=0
+   && zWhere[0]!=0
   ){
-    zSql = sqlite3_mprintf(
-        "SELECT \"%w\" FROM \"%w\""
-        " WHERE \"%w\">=(?1 || ?2)"
-        "   AND \"%w\"<=(?1 || char(1114111))" /* 1114111 == 0x10ffff */
-        " ORDER BY 1 ASC LIMIT 1",
-        zField, zTable, zField, zField);
+    zWhereClause = sqlite3_mprintf("AND (%s)", zWhere);
+    if( zWhereClause==0 ){
+      sqlite3_result_error_nomem(context);
+      return;
+    }
   }else{
-    zSql = sqlite3_mprintf(
-        "SELECT \"%w\" FROM \"%w\""
-        " WHERE \"%w\">=(?1 || ?2)"
-        "   AND \"%w\"<=(?1 || char(1114111))" /* 1114111 == 0x10ffff */
-        "   AND (%s)"
-        " ORDER BY 1 ASC LIMIT 1",
-        zField, zTable, zField, zField, zWhere);
+    zWhereClause = "";
   }
+  if( argc>=5
+   && (zCollName = sqlite3_value_text(argv[4]))!=0
+   && zCollName[0]!=0 
+  ){
+    zColl = sqlite3_mprintf("collate \"%w\"", zCollName);
+    if( zColl==0 ){
+      sqlite3_result_error_nomem(context);
+      if( zWhereClause[0] ) sqlite3_free(zWhereClause);
+      return;
+    }
+  }else{
+    zColl = "";
+  }
+  zSql = sqlite3_mprintf(
+    "SELECT \"%w\" FROM \"%w\""
+    " WHERE \"%w\">=(?1 || ?2) %s"
+    "   AND \"%w\"<=(?1 || char(1114111)) %s" /* 1114111 == 0x10ffff */
+    "   %s"
+    " ORDER BY 1 %s ASC LIMIT 1",
+    zField, zTable, zField, zColl, zField, zColl, zWhereClause, zColl
+  );
+  if( zWhereClause[0] ) sqlite3_free(zWhereClause);
+  if( zColl[0] ) sqlite3_free(zColl);
   if( zSql==0 ){
     sqlite3_result_error_nomem(context);
     return;
@@ -261,5 +290,9 @@ int sqlite3_nextchar_init(
     rc = sqlite3_create_function(db, "next_char", 4, SQLITE_UTF8, 0,
                                  nextCharFunc, 0, 0);
   }
+  if( rc==SQLITE_OK ){
+    rc = sqlite3_create_function(db, "next_char", 5, SQLITE_UTF8, 0,
+                                 nextCharFunc, 0, 0);
+  }
   return rc;
 }
diff --git a/lib/libsqlite3/ext/misc/percentile.c b/lib/libsqlite3/ext/misc/percentile.c
new file mode 100644
index 00000000000..74a4c9d12b4
--- /dev/null
+++ b/lib/libsqlite3/ext/misc/percentile.c
@@ -0,0 +1,219 @@
+/*
+** 2013-05-28
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+******************************************************************************
+**
+** This file contains code to implement the percentile(Y,P) SQL function
+** as described below:
+**
+**   (1)  The percentile(Y,P) function is an aggregate function taking
+**        exactly two arguments.
+**
+**   (2)  If the P argument to percentile(Y,P) is not the same for every
+**        row in the aggregate then an error is thrown.  The word "same"
+**        in the previous sentence means that the value differ by less
+**        than 0.001.
+**
+**   (3)  If the P argument to percentile(Y,P) evaluates to anything other
+**        than a number in the range of 0.0 to 100.0 inclusive then an
+**        error is thrown.
+**
+**   (4)  If any Y argument to percentile(Y,P) evaluates to a value that
+**        is not NULL and is not numeric then an error is thrown.
+**
+**   (5)  If any Y argument to percentile(Y,P) evaluates to plus or minus
+**        infinity then an error is thrown.  (SQLite always interprets NaN
+**        values as NULL.)
+**
+**   (6)  Both Y and P in percentile(Y,P) can be arbitrary expressions,
+**        including CASE WHEN expressions.
+**
+**   (7)  The percentile(Y,P) aggregate is able to handle inputs of at least
+**        one million (1,000,000) rows.
+**
+**   (8)  If there are no non-NULL values for Y, then percentile(Y,P)
+**        returns NULL.
+**
+**   (9)  If there is exactly one non-NULL value for Y, the percentile(Y,P)
+**        returns the one Y value.
+**
+**  (10)  If there N non-NULL values of Y where N is two or more and
+**        the Y values are ordered from least to greatest and a graph is
+**        drawn from 0 to N-1 such that the height of the graph at J is
+**        the J-th Y value and such that straight lines are drawn between
+**        adjacent Y values, then the percentile(Y,P) function returns
+**        the height of the graph at P*(N-1)/100.
+**
+**  (11)  The percentile(Y,P) function always returns either a floating
+**        point number or NULL.
+**
+**  (12)  The percentile(Y,P) is implemented as a single C99 source-code
+**        file that compiles into a shared-library or DLL that can be loaded
+**        into SQLite using the sqlite3_load_extension() interface.
+*/
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT1
+#include <assert.h>
+#include <string.h>
+#include <stdlib.h>
+
+/* The following object is the session context for a single percentile()
+** function.  We have to remember all input Y values until the very end.
+** Those values are accumulated in the Percentile.a[] array.
+*/
+typedef struct Percentile Percentile;
+struct Percentile {
+  unsigned nAlloc;     /* Number of slots allocated for a[] */
+  unsigned nUsed;      /* Number of slots actually used in a[] */
+  double rPct;         /* 1.0 more than the value for P */
+  double *a;           /* Array of Y values */
+};
+
+/*
+** Return TRUE if the input floating-point number is an infinity.
+*/
+static int isInfinity(double r){
+  sqlite3_uint64 u;
+  assert( sizeof(u)==sizeof(r) );
+  memcpy(&u, &r, sizeof(u));
+  return ((u>>52)&0x7ff)==0x7ff;
+}
+
+/*
+** Return TRUE if two doubles differ by 0.001 or less
+*/
+static int sameValue(double a, double b){
+  a -= b;
+  return a>=-0.001 && a<=0.001;
+}
+
+/*
+** The "step" function for percentile(Y,P) is called once for each
+** input row.
+*/
+static void percentStep(sqlite3_context *pCtx, int argc, sqlite3_value **argv){
+  Percentile *p;
+  double rPct;
+  int eType;
+  double y;
+  assert( argc==2 );
+
+  /* Requirement 3:  P must be a number between 0 and 100 */
+  eType = sqlite3_value_numeric_type(argv[1]);
+  rPct = sqlite3_value_double(argv[1]);
+  if( (eType!=SQLITE_INTEGER && eType!=SQLITE_FLOAT) ||
+      ((rPct = sqlite3_value_double(argv[1]))<0.0 || rPct>100.0) ){
+    sqlite3_result_error(pCtx, "2nd argument to percentile() is not "
+                         "a number between 0.0 and 100.0", -1);
+    return;
+  }
+
+  /* Allocate the session context. */
+  p = (Percentile*)sqlite3_aggregate_context(pCtx, sizeof(*p));
+  if( p==0 ) return;
+
+  /* Remember the P value.  Throw an error if the P value is different
+  ** from any prior row, per Requirement (2). */
+  if( p->rPct==0.0 ){
+    p->rPct = rPct+1.0;
+  }else if( !sameValue(p->rPct,rPct+1.0) ){
+    sqlite3_result_error(pCtx, "2nd argument to percentile() is not the "
+                               "same for all input rows", -1);
+    return;
+  }
+
+  /* Ignore rows for which Y is NULL */
+  eType = sqlite3_value_type(argv[0]);
+  if( eType==SQLITE_NULL ) return;
+
+  /* If not NULL, then Y must be numeric.  Otherwise throw an error.
+  ** Requirement 4 */
+  if( eType!=SQLITE_INTEGER && eType!=SQLITE_FLOAT ){
+    sqlite3_result_error(pCtx, "1st argument to percentile() is not "
+                               "numeric", -1);
+    return;
+  }
+
+  /* Throw an error if the Y value is infinity or NaN */
+  y = sqlite3_value_double(argv[0]);
+  if( isInfinity(y) ){
+    sqlite3_result_error(pCtx, "Inf input to percentile()", -1);
+    return;
+  }
+
+  /* Allocate and store the Y */
+  if( p->nUsed>=p->nAlloc ){
+    unsigned n = p->nAlloc*2 + 250;
+    double *a = sqlite3_realloc(p->a, sizeof(double)*n);
+    if( a==0 ){
+      sqlite3_free(p->a);
+      memset(p, 0, sizeof(*p));
+      sqlite3_result_error_nomem(pCtx);
+      return;
+    }
+    p->nAlloc = n;
+    p->a = a;
+  }
+  p->a[p->nUsed++] = y;
+}
+
+/*
+** Compare to doubles for sorting using qsort()
+*/
+static int doubleCmp(const void *pA, const void *pB){
+  double a = *(double*)pA;
+  double b = *(double*)pB;
+  if( a==b ) return 0;
+  if( a<b ) return -1;
+  return +1;
+}
+
+/*
+** Called to compute the final output of percentile() and to clean
+** up all allocated memory.
+*/
+static void percentFinal(sqlite3_context *pCtx){
+  Percentile *p;
+  unsigned i1, i2;
+  double v1, v2;
+  double ix, vx;
+  p = (Percentile*)sqlite3_aggregate_context(pCtx, 0);
+  if( p==0 ) return;
+  if( p->a==0 ) return;
+  if( p->nUsed ){
+    qsort(p->a, p->nUsed, sizeof(double), doubleCmp);
+    ix = (p->rPct-1.0)*(p->nUsed-1)*0.01;
+    i1 = (unsigned)ix;
+    i2 = ix==(double)i1 || i1==p->nUsed-1 ? i1 : i1+1;
+    v1 = p->a[i1];
+    v2 = p->a[i2];
+    vx = v1 + (v2-v1)*(ix-i1);
+    sqlite3_result_double(pCtx, vx);
+  }
+  sqlite3_free(p->a);
+  memset(p, 0, sizeof(*p));
+}
+
+
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_percentile_init(
+  sqlite3 *db, 
+  char **pzErrMsg, 
+  const sqlite3_api_routines *pApi
+){
+  int rc = SQLITE_OK;
+  SQLITE_EXTENSION_INIT2(pApi);
+  (void)pzErrMsg;  /* Unused parameter */
+  rc = sqlite3_create_function(db, "percentile", 2, SQLITE_UTF8, 0,
+                               0, percentStep, percentFinal);
+  return rc;
+}
diff --git a/lib/libsqlite3/ext/misc/regexp.c b/lib/libsqlite3/ext/misc/regexp.c
index 16fa7d0b968..7244d529981 100644
--- a/lib/libsqlite3/ext/misc/regexp.c
+++ b/lib/libsqlite3/ext/misc/regexp.c
@@ -713,6 +713,7 @@ static void re_sql_func(
   const char *zPattern;     /* The regular expression */
   const unsigned char *zStr;/* String being searched */
   const char *zErr;         /* Compile error message */
+  int setAux = 0;           /* True to invoke sqlite3_set_auxdata() */
 
   pRe = sqlite3_get_auxdata(context, 0);
   if( pRe==0 ){
@@ -728,12 +729,15 @@ static void re_sql_func(
       sqlite3_result_error_nomem(context);
       return;
     }
-    sqlite3_set_auxdata(context, 0, pRe, (void(*)(void*))re_free);
+    setAux = 1;
   }
   zStr = (const unsigned char*)sqlite3_value_text(argv[1]);
   if( zStr!=0 ){
     sqlite3_result_int(context, re_match(pRe, zStr, -1));
   }
+  if( setAux ){
+    sqlite3_set_auxdata(context, 0, pRe, (void(*)(void*))re_free);
+  }
 }
 
 /*
diff --git a/lib/libsqlite3/ext/misc/spellfix.c b/lib/libsqlite3/ext/misc/spellfix.c
index eb5442ed2ff..7d4f5e98705 100644
--- a/lib/libsqlite3/ext/misc/spellfix.c
+++ b/lib/libsqlite3/ext/misc/spellfix.c
@@ -2148,10 +2148,10 @@ static int spellfix1BestIndex(sqlite3_vtab *tab, sqlite3_index_info *pIdxInfo){
       pIdxInfo->aConstraintUsage[iDistTerm].argvIndex = idx++;
       pIdxInfo->aConstraintUsage[iDistTerm].omit = 1;
     }
-    pIdxInfo->estimatedCost = (double)10000;
+    pIdxInfo->estimatedCost = 1e5;
   }else{
     pIdxInfo->idxNum = 0;
-    pIdxInfo->estimatedCost = (double)10000000;
+    pIdxInfo->estimatedCost = 1e50;
   }
   return SQLITE_OK;
 }
diff --git a/lib/libsqlite3/ext/misc/vtshim.c b/lib/libsqlite3/ext/misc/vtshim.c
new file mode 100644
index 00000000000..01348e8d3ee
--- /dev/null
+++ b/lib/libsqlite3/ext/misc/vtshim.c
@@ -0,0 +1,551 @@
+/*
+** 2013-06-12
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** A shim that sits between the SQLite virtual table interface and
+** runtimes with garbage collector based memory management.
+*/
+#include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT1
+#include <assert.h>
+#include <string.h>
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+
+/* Forward references */
+typedef struct vtshim_aux vtshim_aux;
+typedef struct vtshim_vtab vtshim_vtab;
+typedef struct vtshim_cursor vtshim_cursor;
+
+
+/* The vtshim_aux argument is the auxiliary parameter that is passed
+** into sqlite3_create_module_v2().
+*/
+struct vtshim_aux {
+  void *pChildAux;              /* pAux for child virtual tables */
+  void (*xChildDestroy)(void*); /* Destructor for pChildAux */
+  sqlite3_module *pMod;         /* Methods for child virtual tables */
+  sqlite3 *db;                  /* The database to which we are attached */
+  char *zName;                  /* Name of the module */
+  int bDisposed;                /* True if disposed */
+  vtshim_vtab *pAllVtab;        /* List of all vtshim_vtab objects */
+  sqlite3_module sSelf;         /* Methods used by this shim */
+};
+
+/* A vtshim virtual table object */
+struct vtshim_vtab {
+  sqlite3_vtab base;       /* Base class - must be first */
+  sqlite3_vtab *pChild;    /* Child virtual table */
+  vtshim_aux *pAux;        /* Pointer to vtshim_aux object */
+  vtshim_cursor *pAllCur;  /* List of all cursors */
+  vtshim_vtab **ppPrev;    /* Previous on list */
+  vtshim_vtab *pNext;      /* Next on list */
+};
+
+/* A vtshim cursor object */
+struct vtshim_cursor {
+  sqlite3_vtab_cursor base;    /* Base class - must be first */
+  sqlite3_vtab_cursor *pChild; /* Cursor generated by the managed subclass */
+  vtshim_cursor **ppPrev;      /* Previous on list of all cursors */
+  vtshim_cursor *pNext;        /* Next on list of all cursors */
+};
+
+/* Macro used to copy the child vtable error message to outer vtable */
+#define VTSHIM_COPY_ERRMSG()                                             \
+  do {                                                                   \
+    sqlite3_free(pVtab->base.zErrMsg);                                   \
+    pVtab->base.zErrMsg = sqlite3_mprintf("%s", pVtab->pChild->zErrMsg); \
+  } while (0)
+
+/* Methods for the vtshim module */
+static int vtshimCreate(
+  sqlite3 *db,
+  void *ppAux,
+  int argc,
+  const char *const*argv,
+  sqlite3_vtab **ppVtab,
+  char **pzErr
+){
+  vtshim_aux *pAux = (vtshim_aux*)ppAux;
+  vtshim_vtab *pNew;
+  int rc;
+
+  assert( db==pAux->db );
+  if( pAux->bDisposed ){
+    if( pzErr ){
+      *pzErr = sqlite3_mprintf("virtual table was disposed: \"%s\"",
+                               pAux->zName);
+    }
+    return SQLITE_ERROR;
+  }
+  pNew = sqlite3_malloc( sizeof(*pNew) );
+  *ppVtab = (sqlite3_vtab*)pNew;
+  if( pNew==0 ) return SQLITE_NOMEM;
+  memset(pNew, 0, sizeof(*pNew));
+  rc = pAux->pMod->xCreate(db, pAux->pChildAux, argc, argv,
+                           &pNew->pChild, pzErr);
+  if( rc ){
+    sqlite3_free(pNew);
+    *ppVtab = 0;
+  }
+  pNew->pAux = pAux;
+  pNew->ppPrev = &pAux->pAllVtab;
+  pNew->pNext = pAux->pAllVtab;
+  if( pAux->pAllVtab ) pAux->pAllVtab->ppPrev = &pNew->pNext;
+  pAux->pAllVtab = pNew;
+  return rc;
+}
+
+static int vtshimConnect(
+  sqlite3 *db,
+  void *ppAux,
+  int argc,
+  const char *const*argv,
+  sqlite3_vtab **ppVtab,
+  char **pzErr
+){
+  vtshim_aux *pAux = (vtshim_aux*)ppAux;
+  vtshim_vtab *pNew;
+  int rc;
+
+  assert( db==pAux->db );
+  if( pAux->bDisposed ){
+    if( pzErr ){
+      *pzErr = sqlite3_mprintf("virtual table was disposed: \"%s\"",
+                               pAux->zName);
+    }
+    return SQLITE_ERROR;
+  }
+  pNew = sqlite3_malloc( sizeof(*pNew) );
+  *ppVtab = (sqlite3_vtab*)pNew;
+  if( pNew==0 ) return SQLITE_NOMEM;
+  memset(pNew, 0, sizeof(*pNew));
+  rc = pAux->pMod->xConnect(db, pAux->pChildAux, argc, argv,
+                            &pNew->pChild, pzErr);
+  if( rc ){
+    sqlite3_free(pNew);
+    *ppVtab = 0;
+  }
+  pNew->pAux = pAux;
+  pNew->ppPrev = &pAux->pAllVtab;
+  pNew->pNext = pAux->pAllVtab;
+  if( pAux->pAllVtab ) pAux->pAllVtab->ppPrev = &pNew->pNext;
+  pAux->pAllVtab = pNew;
+  return rc;
+}
+
+static int vtshimBestIndex(
+  sqlite3_vtab *pBase,
+  sqlite3_index_info *pIdxInfo
+){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xBestIndex(pVtab->pChild, pIdxInfo);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+static int vtshimDisconnect(sqlite3_vtab *pBase){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc = SQLITE_OK;
+  if( !pAux->bDisposed ){
+    rc = pAux->pMod->xDisconnect(pVtab->pChild);
+  }
+  if( pVtab->pNext ) pVtab->pNext->ppPrev = pVtab->ppPrev;
+  *pVtab->ppPrev = pVtab->pNext;
+  sqlite3_free(pVtab);
+  return rc;
+}
+
+static int vtshimDestroy(sqlite3_vtab *pBase){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc = SQLITE_OK;
+  if( !pAux->bDisposed ){
+    rc = pAux->pMod->xDestroy(pVtab->pChild);
+  }
+  if( pVtab->pNext ) pVtab->pNext->ppPrev = pVtab->ppPrev;
+  *pVtab->ppPrev = pVtab->pNext;
+  sqlite3_free(pVtab);
+  return rc;
+}
+
+static int vtshimOpen(sqlite3_vtab *pBase, sqlite3_vtab_cursor **ppCursor){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  vtshim_cursor *pCur;
+  int rc;
+  *ppCursor = 0;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  pCur = sqlite3_malloc( sizeof(*pCur) );
+  if( pCur==0 ) return SQLITE_NOMEM;
+  memset(pCur, 0, sizeof(*pCur));
+  rc = pAux->pMod->xOpen(pVtab->pChild, &pCur->pChild);
+  if( rc ){
+    sqlite3_free(pCur);
+    VTSHIM_COPY_ERRMSG();
+    return rc;
+  }
+  pCur->pChild->pVtab = pVtab->pChild;
+  *ppCursor = &pCur->base;
+  pCur->ppPrev = &pVtab->pAllCur;
+  if( pVtab->pAllCur ) pVtab->pAllCur->ppPrev = &pCur->pNext;
+  pCur->pNext = pVtab->pAllCur;
+  pVtab->pAllCur = pCur;
+  return SQLITE_OK;
+}
+
+static int vtshimClose(sqlite3_vtab_cursor *pX){
+  vtshim_cursor *pCur = (vtshim_cursor*)pX;
+  vtshim_vtab *pVtab = (vtshim_vtab*)pCur->base.pVtab;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc = SQLITE_OK;
+  if( !pAux->bDisposed ){
+    rc = pAux->pMod->xClose(pCur->pChild);
+    if( rc!=SQLITE_OK ){
+      VTSHIM_COPY_ERRMSG();
+    }
+  }
+  if( pCur->pNext ) pCur->pNext->ppPrev = pCur->ppPrev;
+  *pCur->ppPrev = pCur->pNext;
+  sqlite3_free(pCur);
+  return rc;
+}
+
+static int vtshimFilter(
+  sqlite3_vtab_cursor *pX,
+  int idxNum,
+  const char *idxStr,
+  int argc,
+  sqlite3_value **argv
+){
+  vtshim_cursor *pCur = (vtshim_cursor*)pX;
+  vtshim_vtab *pVtab = (vtshim_vtab*)pCur->base.pVtab;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xFilter(pCur->pChild, idxNum, idxStr, argc, argv);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+static int vtshimNext(sqlite3_vtab_cursor *pX){
+  vtshim_cursor *pCur = (vtshim_cursor*)pX;
+  vtshim_vtab *pVtab = (vtshim_vtab*)pCur->base.pVtab;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xNext(pCur->pChild);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+static int vtshimEof(sqlite3_vtab_cursor *pX){
+  vtshim_cursor *pCur = (vtshim_cursor*)pX;
+  vtshim_vtab *pVtab = (vtshim_vtab*)pCur->base.pVtab;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return 1;
+  rc = pAux->pMod->xEof(pCur->pChild);
+  VTSHIM_COPY_ERRMSG();
+  return rc;
+}
+
+static int vtshimColumn(sqlite3_vtab_cursor *pX, sqlite3_context *ctx, int i){
+  vtshim_cursor *pCur = (vtshim_cursor*)pX;
+  vtshim_vtab *pVtab = (vtshim_vtab*)pCur->base.pVtab;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xColumn(pCur->pChild, ctx, i);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+static int vtshimRowid(sqlite3_vtab_cursor *pX, sqlite3_int64 *pRowid){
+  vtshim_cursor *pCur = (vtshim_cursor*)pX;
+  vtshim_vtab *pVtab = (vtshim_vtab*)pCur->base.pVtab;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xRowid(pCur->pChild, pRowid);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+static int vtshimUpdate(
+  sqlite3_vtab *pBase,
+  int argc,
+  sqlite3_value **argv,
+  sqlite3_int64 *pRowid
+){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xUpdate(pVtab->pChild, argc, argv, pRowid);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+static int vtshimBegin(sqlite3_vtab *pBase){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xBegin(pVtab->pChild);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+static int vtshimSync(sqlite3_vtab *pBase){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xSync(pVtab->pChild);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+static int vtshimCommit(sqlite3_vtab *pBase){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xCommit(pVtab->pChild);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+static int vtshimRollback(sqlite3_vtab *pBase){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xRollback(pVtab->pChild);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+static int vtshimFindFunction(
+  sqlite3_vtab *pBase,
+  int nArg,
+  const char *zName,
+  void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
+  void **ppArg
+){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return 0;
+  rc = pAux->pMod->xFindFunction(pVtab->pChild, nArg, zName, pxFunc, ppArg);
+  VTSHIM_COPY_ERRMSG();
+  return rc;
+}
+
+static int vtshimRename(sqlite3_vtab *pBase, const char *zNewName){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xRename(pVtab->pChild, zNewName);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+static int vtshimSavepoint(sqlite3_vtab *pBase, int n){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xSavepoint(pVtab->pChild, n);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+static int vtshimRelease(sqlite3_vtab *pBase, int n){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xRelease(pVtab->pChild, n);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+static int vtshimRollbackTo(sqlite3_vtab *pBase, int n){
+  vtshim_vtab *pVtab = (vtshim_vtab*)pBase;
+  vtshim_aux *pAux = pVtab->pAux;
+  int rc;
+  if( pAux->bDisposed ) return SQLITE_ERROR;
+  rc = pAux->pMod->xRollbackTo(pVtab->pChild, n);
+  if( rc!=SQLITE_OK ){
+    VTSHIM_COPY_ERRMSG();
+  }
+  return rc;
+}
+
+/* The destructor function for a disposible module */
+static void vtshimAuxDestructor(void *pXAux){
+  vtshim_aux *pAux = (vtshim_aux*)pXAux;
+  assert( pAux->pAllVtab==0 );
+  if( !pAux->bDisposed && pAux->xChildDestroy ){
+    pAux->xChildDestroy(pAux->pChildAux);
+    pAux->xChildDestroy = 0;
+  }
+  sqlite3_free(pAux->zName);
+  sqlite3_free(pAux->pMod);
+  sqlite3_free(pAux);
+}
+
+static int vtshimCopyModule(
+  const sqlite3_module *pMod,   /* Source module to be copied */
+  sqlite3_module **ppMod        /* Destination for copied module */
+){
+  sqlite3_module *p;
+  if( !pMod || !ppMod ) return SQLITE_ERROR;
+  p = sqlite3_malloc( sizeof(*p) );
+  if( p==0 ) return SQLITE_NOMEM;
+  memcpy(p, pMod, sizeof(*p));
+  *ppMod = p;
+  return SQLITE_OK;
+}
+
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+void *sqlite3_create_disposable_module(
+  sqlite3 *db,               /* SQLite connection to register module with */
+  const char *zName,         /* Name of the module */
+  const sqlite3_module *p,   /* Methods for the module */
+  void *pClientData,         /* Client data for xCreate/xConnect */
+  void(*xDestroy)(void*)     /* Module destructor function */
+){
+  vtshim_aux *pAux;
+  sqlite3_module *pMod;
+  int rc;
+  pAux = sqlite3_malloc( sizeof(*pAux) );
+  if( pAux==0 ){
+    if( xDestroy ) xDestroy(pClientData);
+    return 0;
+  }
+  rc = vtshimCopyModule(p, &pMod);
+  if( rc!=SQLITE_OK ){
+    sqlite3_free(pAux);
+    return 0;
+  }
+  pAux->pChildAux = pClientData;
+  pAux->xChildDestroy = xDestroy;
+  pAux->pMod = pMod;
+  pAux->db = db;
+  pAux->zName = sqlite3_mprintf("%s", zName);
+  pAux->bDisposed = 0;
+  pAux->pAllVtab = 0;
+  pAux->sSelf.iVersion = p->iVersion<=2 ? p->iVersion : 2;
+  pAux->sSelf.xCreate = p->xCreate ? vtshimCreate : 0;
+  pAux->sSelf.xConnect = p->xConnect ? vtshimConnect : 0;
+  pAux->sSelf.xBestIndex = p->xBestIndex ? vtshimBestIndex : 0;
+  pAux->sSelf.xDisconnect = p->xDisconnect ? vtshimDisconnect : 0;
+  pAux->sSelf.xDestroy = p->xDestroy ? vtshimDestroy : 0;
+  pAux->sSelf.xOpen = p->xOpen ? vtshimOpen : 0;
+  pAux->sSelf.xClose = p->xClose ? vtshimClose : 0;
+  pAux->sSelf.xFilter = p->xFilter ? vtshimFilter : 0;
+  pAux->sSelf.xNext = p->xNext ? vtshimNext : 0;
+  pAux->sSelf.xEof = p->xEof ? vtshimEof : 0;
+  pAux->sSelf.xColumn = p->xColumn ? vtshimColumn : 0;
+  pAux->sSelf.xRowid = p->xRowid ? vtshimRowid : 0;
+  pAux->sSelf.xUpdate = p->xUpdate ? vtshimUpdate : 0;
+  pAux->sSelf.xBegin = p->xBegin ? vtshimBegin : 0;
+  pAux->sSelf.xSync = p->xSync ? vtshimSync : 0;
+  pAux->sSelf.xCommit = p->xCommit ? vtshimCommit : 0;
+  pAux->sSelf.xRollback = p->xRollback ? vtshimRollback : 0;
+  pAux->sSelf.xFindFunction = p->xFindFunction ? vtshimFindFunction : 0;
+  pAux->sSelf.xRename = p->xRename ? vtshimRename : 0;
+  if( p->iVersion>=2 ){
+    pAux->sSelf.xSavepoint = p->xSavepoint ? vtshimSavepoint : 0;
+    pAux->sSelf.xRelease = p->xRelease ? vtshimRelease : 0;
+    pAux->sSelf.xRollbackTo = p->xRollbackTo ? vtshimRollbackTo : 0;
+  }else{
+    pAux->sSelf.xSavepoint = 0;
+    pAux->sSelf.xRelease = 0;
+    pAux->sSelf.xRollbackTo = 0;
+  }
+  rc = sqlite3_create_module_v2(db, zName, &pAux->sSelf,
+                                pAux, vtshimAuxDestructor);
+  return rc==SQLITE_OK ? (void*)pAux : 0;
+}
+
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+void sqlite3_dispose_module(void *pX){
+  vtshim_aux *pAux = (vtshim_aux*)pX;
+  if( !pAux->bDisposed ){
+    vtshim_vtab *pVtab;
+    vtshim_cursor *pCur;
+    for(pVtab=pAux->pAllVtab; pVtab; pVtab=pVtab->pNext){
+      for(pCur=pVtab->pAllCur; pCur; pCur=pCur->pNext){
+        pAux->pMod->xClose(pCur->pChild);
+      }
+      pAux->pMod->xDisconnect(pVtab->pChild);
+    }
+    pAux->bDisposed = 1;
+    if( pAux->xChildDestroy ){
+      pAux->xChildDestroy(pAux->pChildAux);
+      pAux->xChildDestroy = 0;
+    }
+  }
+}
+
+
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_vtshim_init(
+  sqlite3 *db,
+  char **pzErrMsg,
+  const sqlite3_api_routines *pApi
+){
+  SQLITE_EXTENSION_INIT2(pApi);
+  return SQLITE_OK;
+}
diff --git a/lib/libsqlite3/ext/rtree/rtree.c b/lib/libsqlite3/ext/rtree/rtree.c
index 16a316f400c..815a8993e4f 100644
--- a/lib/libsqlite3/ext/rtree/rtree.c
+++ b/lib/libsqlite3/ext/rtree/rtree.c
@@ -3350,7 +3350,10 @@ int sqlite3_rtree_geometry_callback(
 }
 
 #if !SQLITE_CORE
-int sqlite3_extension_init(
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_rtree_init(
   sqlite3 *db,
   char **pzErrMsg,
   const sqlite3_api_routines *pApi
diff --git a/lib/libsqlite3/ext/rtree/rtree6.test b/lib/libsqlite3/ext/rtree/rtree6.test
index 92edc8d104c..17985ee5256 100644
--- a/lib/libsqlite3/ext/rtree/rtree6.test
+++ b/lib/libsqlite3/ext/rtree/rtree6.test
@@ -74,36 +74,36 @@ do_test rtree6-1.5 {
 do_eqp_test rtree6.2.1 {
   SELECT * FROM t1,t2 WHERE k=+ii AND x1<10
 } {
-  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2:Ca (~0 rows)} 
-  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?) (~1 rows)}
+  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2:Ca} 
+  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?)}
 }
 
 do_eqp_test rtree6.2.2 {
   SELECT * FROM t1,t2 WHERE k=ii AND x1<10
 } {
-  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2:Ca (~0 rows)} 
-  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?) (~1 rows)}
+  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2:Ca} 
+  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?)}
 }
 
 do_eqp_test rtree6.2.3 {
   SELECT * FROM t1,t2 WHERE k=ii
 } {
-  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2: (~0 rows)} 
-  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?) (~1 rows)}
+  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2:} 
+  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?)}
 }
 
 do_eqp_test rtree6.2.4 {
   SELECT * FROM t1,t2 WHERE v=10 and x1<10 and x2>10
 } {
-  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2:CaEb (~0 rows)} 
-  0 1 1 {SCAN TABLE t2 (~100000 rows)}
+  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2:CaEb} 
+  0 1 1 {SCAN TABLE t2}
 }
 
 do_eqp_test rtree6.2.5 {
   SELECT * FROM t1,t2 WHERE k=ii AND x1<v
 } {
-  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2: (~0 rows)} 
-  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?) (~1 rows)}
+  0 0 0 {SCAN TABLE t1 VIRTUAL TABLE INDEX 2:} 
+  0 1 1 {SEARCH TABLE t2 USING INTEGER PRIMARY KEY (rowid=?)}
 }
 
 do_execsql_test rtree6-3.1 {
diff --git a/lib/libsqlite3/ext/rtree/rtree8.test b/lib/libsqlite3/ext/rtree/rtree8.test
index bf22cbf4844..578a1468b8b 100644
--- a/lib/libsqlite3/ext/rtree/rtree8.test
+++ b/lib/libsqlite3/ext/rtree/rtree8.test
@@ -168,4 +168,3 @@ do_test rtree8-5.3 {
 
 
 finish_test
-
diff --git a/lib/libsqlite3/mkopcodeh.awk b/lib/libsqlite3/mkopcodeh.awk
index f6b90c114dd..9685c3a0e86 100644
--- a/lib/libsqlite3/mkopcodeh.awk
+++ b/lib/libsqlite3/mkopcodeh.awk
@@ -35,7 +35,7 @@
 
 # Remember the TK_ values from the parse.h file
 /^#define TK_/ {
-  tk[$2] = 0+$3
+  tk[$2] = 0+$3    # tk[x] holds the numeric value for TK symbol X
 }
 
 # Scan for "case OP_aaaa:" lines in the vdbe.c file
@@ -43,7 +43,7 @@
   name = $2
   sub(/:/,"",name)
   sub("\r","",name)
-  op[name] = -1
+  op[name] = -1       # op[x] holds the numeric value for OP symbol x
   jump[name] = 0
   out2_prerelease[name] = 0
   in1[name] = 0
@@ -55,9 +55,11 @@
     if($i=="same" && $(i+1)=="as"){
       sym = $(i+2)
       sub(/,/,"",sym)
-      op[name] = tk[sym]
-      used[op[name]] = 1
-      sameas[op[name]] = sym
+      val = tk[sym]
+      op[name] = val
+      used[val] = 1
+      sameas[val] = sym
+      def[val] = name
     }
     x = $i
     sub(",","",x)
@@ -90,31 +92,55 @@ END {
   order[n_op++] = "OP_Noop";
   op["OP_Explain"] = -1;
   order[n_op++] = "OP_Explain";
+
+  # Assign small values to opcodes that are processed by resolveP2Values()
+  # to make code generation for the switch() statement smaller and faster.
   for(i=0; i<n_op; i++){
     name = order[i];
-    if( op[name]<0 ){
+    if( op[name]>=0 ) continue;
+    if( name=="OP_Function"      \
+     || name=="OP_AggStep"       \
+     || name=="OP_Transaction"   \
+     || name=="OP_AutoCommit"    \
+     || name=="OP_Savepoint"     \
+     || name=="OP_Checkpoint"    \
+     || name=="OP_Vacuum"        \
+     || name=="OP_JournalMode"   \
+     || name=="OP_VUpdate"       \
+     || name=="OP_VFilter"       \
+     || name=="OP_Next"          \
+     || name=="OP_SorterNext"    \
+     || name=="OP_Prev"          \
+    ){
       cnt++
       while( used[cnt] ) cnt++
       op[name] = cnt
+      used[cnt] = 1
+      def[cnt] = name
     }
-    used[op[name]] = 1;
-    if( op[name]>max ) max = op[name]
-    printf "#define %-25s %15d", name, op[name]
-    if( sameas[op[name]] ) {
-      printf "   /* same as %-12s*/", sameas[op[name]]
-    } 
-    printf "\n"
+  }
 
+  # Generate the numeric values for opcodes
+  for(i=0; i<n_op; i++){
+    name = order[i];
+    if( op[name]<0 ){
+      cnt++
+      while( used[cnt] ) cnt++
+      op[name] = cnt
+      used[cnt] = 1
+      def[cnt] = name
+    }
   }
-  seenUnused = 0;
-  for(i=1; i<max; i++){
+  max = cnt
+  for(i=1; i<=max; i++){
     if( !used[i] ){
-      if( !seenUnused ){
-        printf "\n/* The following opcode values are never used */\n"
-        seenUnused = 1
-      }
-      printf "#define %-25s %15d\n", sprintf( "OP_NotUsed_%-3d", i ), i
+      def[i] = "OP_NotUsed_" i 
     }
+    printf "#define %-25s %15d", def[i], i
+    if( sameas[i] ){
+      printf "   /* same as %-12s*/", sameas[i]
+    } 
+    printf "\n"
   }
 
   # Generate the bitvectors:
@@ -123,12 +149,9 @@ END {
   #  bit 1:     pushes a result onto stack
   #  bit 2:     output to p1.  release p1 before opcode runs
   #
-  for(i=0; i<=max; i++) bv[i] = 0;
-  for(i=0; i<n_op; i++){
-    name = order[i];
-    x = op[name]
+  for(i=0; i<=max; i++){
+    name = def[i]
     a0 = a1 = a2 = a3 = a4 = a5 = a6 = a7 = 0
-    # a7 = a9 = a10 = a11 = a12 = a13 = a14 = a15 = 0
     if( jump[name] ) a0 = 1;
     if( out2_prerelease[name] ) a1 = 2;
     if( in1[name] ) a2 = 4;
@@ -136,8 +159,7 @@ END {
     if( in3[name] ) a4 = 16;
     if( out2[name] ) a5 = 32;
     if( out3[name] ) a6 = 64;
-    # bv[x] = a0+a1+a2+a3+a4+a5+a6+a7+a8+a9+a10+a11+a12+a13+a14+a15;
-    bv[x] = a0+a1+a2+a3+a4+a5+a6+a7;
+    bv[i] = a0+a1+a2+a3+a4+a5+a6+a7;
   }
   print "\n"
   print "/* Properties such as \"out2\" or \"jump\" that are specified in"
diff --git a/lib/libsqlite3/sqlite3.pc.in b/lib/libsqlite3/sqlite3.pc.in
index c8d0aa9d5dc..3799671e613 100644
--- a/lib/libsqlite3/sqlite3.pc.in
+++ b/lib/libsqlite3/sqlite3.pc.in
@@ -7,7 +7,7 @@ includedir=@includedir@
 
 Name: SQLite
 Description: SQL database engine
-Version: @RELEASE@
+Version: @PACKAGE_VERSION@
 Libs: -L${libdir} -lsqlite3
 Libs.private: @LIBS@
 Cflags: -I${includedir}
diff --git a/lib/libsqlite3/src/analyze.c b/lib/libsqlite3/src/analyze.c
index 9a3e9597db0..d25a9b196cf 100644
--- a/lib/libsqlite3/src/analyze.c
+++ b/lib/libsqlite3/src/analyze.c
@@ -25,7 +25,7 @@
 ** The sqlite_stat2 table is not created or used unless the SQLite version
 ** is between 3.6.18 and 3.7.8, inclusive, and unless SQLite is compiled
 ** with SQLITE_ENABLE_STAT2.  The sqlite_stat2 table is deprecated.
-** The sqlite_stat2 table is superceded by sqlite_stat3, which is only
+** The sqlite_stat2 table is superseded by sqlite_stat3, which is only
 ** created and used by SQLite versions 3.7.9 and later and with
 ** SQLITE_ENABLE_STAT3 defined.  The fucntionality of sqlite_stat3
 ** is a superset of sqlite_stat2.  
@@ -441,6 +441,7 @@ static void analyzeOneTable(
   int endOfLoop;               /* The end of the loop */
   int jZeroRows = -1;          /* Jump from here if number of rows is zero */
   int iDb;                     /* Index of database containing pTab */
+  u8 needTableCnt = 1;         /* True to count the table */
   int regTabname = iMem++;     /* Register containing table name */
   int regIdxname = iMem++;     /* Register containing index name */
   int regStat1 = iMem++;       /* The stat column of sqlite_stat1 */
@@ -500,6 +501,7 @@ static void analyzeOneTable(
     int *aChngAddr;              /* Array of jump instruction addresses */
 
     if( pOnlyIdx && pOnlyIdx!=pIdx ) continue;
+    if( pIdx->pPartIdxWhere==0 ) needTableCnt = 0;
     VdbeNoopComment((v, "Begin analysis of %s", pIdx->zName));
     nCol = pIdx->nColumn;
     aChngAddr = sqlite3DbMallocRaw(db, sizeof(int)*nCol);
@@ -659,9 +661,7 @@ static void analyzeOneTable(
     ** is never possible.
     */
     sqlite3VdbeAddOp2(v, OP_SCopy, iMem, regStat1);
-    if( jZeroRows<0 ){
-      jZeroRows = sqlite3VdbeAddOp1(v, OP_IfNot, iMem);
-    }
+    jZeroRows = sqlite3VdbeAddOp1(v, OP_IfNot, iMem);
     for(i=0; i<nCol; i++){
       sqlite3VdbeAddOp4(v, OP_String8, 0, regTemp, 0, " ", 0);
       sqlite3VdbeAddOp3(v, OP_Concat, regTemp, regStat1, regStat1);
@@ -671,32 +671,31 @@ static void analyzeOneTable(
       sqlite3VdbeAddOp1(v, OP_ToInt, regTemp);
       sqlite3VdbeAddOp3(v, OP_Concat, regTemp, regStat1, regStat1);
     }
+    if( pIdx->pPartIdxWhere!=0 ) sqlite3VdbeJumpHere(v, jZeroRows);
     sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regRec, "aaa", 0);
     sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regNewRowid);
     sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regNewRowid);
     sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
+    if( pIdx->pPartIdxWhere==0 ) sqlite3VdbeJumpHere(v, jZeroRows);
   }
 
-  /* If the table has no indices, create a single sqlite_stat1 entry
-  ** containing NULL as the index name and the row count as the content.
+  /* Create a single sqlite_stat1 entry containing NULL as the index
+  ** name and the row count as the content.
   */
-  if( pTab->pIndex==0 ){
+  if( pOnlyIdx==0 && needTableCnt ){
     sqlite3VdbeAddOp3(v, OP_OpenRead, iIdxCur, pTab->tnum, iDb);
     VdbeComment((v, "%s", pTab->zName));
     sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regStat1);
     sqlite3VdbeAddOp1(v, OP_Close, iIdxCur);
     jZeroRows = sqlite3VdbeAddOp1(v, OP_IfNot, regStat1);
-  }else{
+    sqlite3VdbeAddOp2(v, OP_Null, 0, regIdxname);
+    sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regRec, "aaa", 0);
+    sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regNewRowid);
+    sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regNewRowid);
+    sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
     sqlite3VdbeJumpHere(v, jZeroRows);
-    jZeroRows = sqlite3VdbeAddOp0(v, OP_Goto);
   }
-  sqlite3VdbeAddOp2(v, OP_Null, 0, regIdxname);
-  sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regRec, "aaa", 0);
-  sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regNewRowid);
-  sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regRec, regNewRowid);
-  sqlite3VdbeChangeP5(v, OPFLAG_APPEND);
   if( pParse->nMem<regRec ) pParse->nMem = regRec;
-  sqlite3VdbeJumpHere(v, jZeroRows);
 }
 
 
@@ -879,8 +878,10 @@ static int analysisLoader(void *pData, int argc, char **argv, char **NotUsed){
       v = v*10 + c - '0';
       z++;
     }
-    if( i==0 ) pTable->nRowEst = v;
-    if( pIndex==0 ) break;
+    if( i==0 && (pIndex==0 || pIndex->pPartIdxWhere==0) ){
+      if( v>0 ) pTable->nRowEst = v;
+      if( pIndex==0 ) break;
+    }
     pIndex->aiRowEst[i] = v;
     if( *z==' ' ) z++;
     if( strcmp(z, "unordered")==0 ){
diff --git a/lib/libsqlite3/src/attach.c b/lib/libsqlite3/src/attach.c
index b8e12199b57..ce95ea702e1 100644
--- a/lib/libsqlite3/src/attach.c
+++ b/lib/libsqlite3/src/attach.c
@@ -158,6 +158,9 @@ static void attachFunc(
     sqlite3PagerLockingMode(pPager, db->dfltLockMode);
     sqlite3BtreeSecureDelete(aNew->pBt,
                              sqlite3BtreeSecureDelete(db->aDb[0].pBt,-1) );
+#ifndef SQLITE_OMIT_PAGER_PRAGMAS
+    sqlite3BtreeSetPagerFlags(aNew->pBt, 3 | (db->flags & PAGER_FLAGS_MASK));
+#endif
   }
   aNew->safety_level = 3;
   aNew->zName = sqlite3DbStrDup(db, zName);
diff --git a/lib/libsqlite3/src/backup.c b/lib/libsqlite3/src/backup.c
index 252f61cfcaa..afbaeeb1097 100644
--- a/lib/libsqlite3/src/backup.c
+++ b/lib/libsqlite3/src/backup.c
@@ -15,12 +15,6 @@
 #include "sqliteInt.h"
 #include "btreeInt.h"
 
-/* Macro to find the minimum of two numeric values.
-*/
-#ifndef MIN
-# define MIN(x,y) ((x)<(y)?(x):(y))
-#endif
-
 /*
 ** Structure allocated for each backup operation.
 */
@@ -398,7 +392,7 @@ int sqlite3_backup_step(sqlite3_backup *p, int nPage){
       if( iSrcPg!=PENDING_BYTE_PAGE(p->pSrc->pBt) ){
         DbPage *pSrcPg;                             /* Source page object */
         rc = sqlite3PagerAcquire(pSrcPager, iSrcPg, &pSrcPg,
-                                 PAGER_ACQUIRE_READONLY);
+                                 PAGER_GET_READONLY);
         if( rc==SQLITE_OK ){
           rc = backupOnePage(p, iSrcPg, sqlite3PagerGetData(pSrcPg), 0);
           sqlite3PagerUnref(pSrcPg);
diff --git a/lib/libsqlite3/src/btree.c b/lib/libsqlite3/src/btree.c
index 3ca60583e3c..d6fb5834c5c 100644
--- a/lib/libsqlite3/src/btree.c
+++ b/lib/libsqlite3/src/btree.c
@@ -724,6 +724,9 @@ static int btreeRestoreCursorPosition(BtCursor *pCur){
     sqlite3_free(pCur->pKey);
     pCur->pKey = 0;
     assert( pCur->eState==CURSOR_VALID || pCur->eState==CURSOR_INVALID );
+    if( pCur->skipNext && pCur->eState==CURSOR_VALID ){
+      pCur->eState = CURSOR_SKIPNEXT;
+    }
   }
   return rc;
 }
@@ -749,7 +752,7 @@ int sqlite3BtreeCursorHasMoved(BtCursor *pCur, int *pHasMoved){
     *pHasMoved = 1;
     return rc;
   }
-  if( pCur->eState!=CURSOR_VALID || pCur->skipNext!=0 ){
+  if( pCur->eState!=CURSOR_VALID || NEVER(pCur->skipNext!=0) ){
     *pHasMoved = 1;
   }else{
     *pHasMoved = 0;
@@ -937,7 +940,8 @@ static void btreeParseCellPtr(
   assert( n==4-4*pPage->leaf );
   if( pPage->intKey ){
     if( pPage->hasData ){
-      n += getVarint32(&pCell[n], nPayload);
+      assert( n==0 );
+      n = getVarint32(pCell, nPayload);
     }else{
       nPayload = 0;
     }
@@ -1215,7 +1219,7 @@ static int allocateSpace(MemPage *pPage, int nByte, int *pIdx){
   }else if( gap+2<=top ){
     /* Search the freelist looking for a free slot big enough to satisfy 
     ** the request. The allocation is made from the first free slot in 
-    ** the list that is large enough to accomadate it.
+    ** the list that is large enough to accommodate it.
     */
     int pc, addr;
     for(addr=hdr+1; (pc = get2byte(&data[addr]))>0; addr=pc){
@@ -1581,15 +1585,12 @@ static int btreeGetPage(
   BtShared *pBt,       /* The btree */
   Pgno pgno,           /* Number of the page to fetch */
   MemPage **ppPage,    /* Return the page in this parameter */
-  int noContent,       /* Do not load page content if true */
-  int bReadonly        /* True if a read-only (mmap) page is ok */
+  int flags            /* PAGER_GET_NOCONTENT or PAGER_GET_READONLY */
 ){
   int rc;
   DbPage *pDbPage;
-  int flags = (noContent ? PAGER_ACQUIRE_NOCONTENT : 0) 
-            | (bReadonly ? PAGER_ACQUIRE_READONLY : 0);
 
-  assert( noContent==0 || bReadonly==0 );
+  assert( flags==0 || flags==PAGER_GET_NOCONTENT || flags==PAGER_GET_READONLY );
   assert( sqlite3_mutex_held(pBt->mutex) );
   rc = sqlite3PagerAcquire(pBt->pPager, pgno, (DbPage**)&pDbPage, flags);
   if( rc ) return rc;
@@ -1637,15 +1638,16 @@ static int getAndInitPage(
   BtShared *pBt,                  /* The database file */
   Pgno pgno,                      /* Number of the page to get */
   MemPage **ppPage,               /* Write the page pointer here */
-  int bReadonly                   /* True if a read-only (mmap) page is ok */
+  int bReadonly                   /* PAGER_GET_READONLY or 0 */
 ){
   int rc;
   assert( sqlite3_mutex_held(pBt->mutex) );
+  assert( bReadonly==PAGER_GET_READONLY || bReadonly==0 );
 
   if( pgno>btreePagecount(pBt) ){
     rc = SQLITE_CORRUPT_BKPT;
   }else{
-    rc = btreeGetPage(pBt, pgno, ppPage, 0, bReadonly);
+    rc = btreeGetPage(pBt, pgno, ppPage, bReadonly);
     if( rc==SQLITE_OK ){
       rc = btreeInitPage(*ppPage);
       if( rc!=SQLITE_OK ){
@@ -2165,17 +2167,14 @@ int sqlite3BtreeSetMmapLimit(Btree *p, sqlite3_int64 szMmap){
 ** probability of damage to near zero but with a write performance reduction.
 */
 #ifndef SQLITE_OMIT_PAGER_PRAGMAS
-int sqlite3BtreeSetSafetyLevel(
+int sqlite3BtreeSetPagerFlags(
   Btree *p,              /* The btree to set the safety level on */
-  int level,             /* PRAGMA synchronous.  1=OFF, 2=NORMAL, 3=FULL */
-  int fullSync,          /* PRAGMA fullfsync. */
-  int ckptFullSync       /* PRAGMA checkpoint_fullfync */
+  unsigned pgFlags       /* Various PAGER_* flags */
 ){
   BtShared *pBt = p->pBt;
   assert( sqlite3_mutex_held(p->db->mutex) );
-  assert( level>=1 && level<=3 );
   sqlite3BtreeEnter(p);
-  sqlite3PagerSetSafetyLevel(pBt->pPager, level, fullSync, ckptFullSync);
+  sqlite3PagerSetFlags(pBt->pPager, pgFlags);
   sqlite3BtreeLeave(p);
   return SQLITE_OK;
 }
@@ -2381,7 +2380,7 @@ static int lockBtree(BtShared *pBt){
   assert( pBt->pPage1==0 );
   rc = sqlite3PagerSharedLock(pBt->pPager);
   if( rc!=SQLITE_OK ) return rc;
-  rc = btreeGetPage(pBt, 1, &pPage1, 0, 0);
+  rc = btreeGetPage(pBt, 1, &pPage1, 0);
   if( rc!=SQLITE_OK ) return rc;
 
   /* Do some checking to help insure the file we opened really is
@@ -2963,7 +2962,7 @@ static int relocatePage(
   ** iPtrPage.
   */
   if( eType!=PTRMAP_ROOTPAGE ){
-    rc = btreeGetPage(pBt, iPtrPage, &pPtrPage, 0, 0);
+    rc = btreeGetPage(pBt, iPtrPage, &pPtrPage, 0);
     if( rc!=SQLITE_OK ){
       return rc;
     }
@@ -3047,7 +3046,7 @@ static int incrVacuumStep(BtShared *pBt, Pgno nFin, Pgno iLastPg, int bCommit){
       u8 eMode = BTALLOC_ANY;   /* Mode parameter for allocateBtreePage() */
       Pgno iNear = 0;           /* nearby parameter for allocateBtreePage() */
 
-      rc = btreeGetPage(pBt, iLastPg, &pLastPg, 0, 0);
+      rc = btreeGetPage(pBt, iLastPg, &pLastPg, 0);
       if( rc!=SQLITE_OK ){
         return rc;
       }
@@ -3158,7 +3157,7 @@ int sqlite3BtreeIncrVacuum(Btree *p){
 
 /*
 ** This routine is called prior to sqlite3PagerCommit when a transaction
-** is commited for an auto-vacuum database.
+** is committed for an auto-vacuum database.
 **
 ** If SQLITE_OK is returned, then *pnTrunc is set to the number of pages
 ** the database file should be truncated to during the commit process. 
@@ -3273,12 +3272,13 @@ int sqlite3BtreeCommitPhaseOne(Btree *p, const char *zMaster){
 */
 static void btreeEndTransaction(Btree *p){
   BtShared *pBt = p->pBt;
+  sqlite3 *db = p->db;
   assert( sqlite3BtreeHoldsMutex(p) );
 
 #ifndef SQLITE_OMIT_AUTOVACUUM
   pBt->bDoTruncate = 0;
 #endif
-  if( p->inTrans>TRANS_NONE && p->db->activeVdbeCnt>1 ){
+  if( p->inTrans>TRANS_NONE && db->nVdbeRead>1 ){
     /* If there are other active statements that belong to this database
     ** handle, downgrade to a read-only transaction. The other statements
     ** may still be reading from the database.  */
@@ -3445,7 +3445,7 @@ int sqlite3BtreeRollback(Btree *p, int tripCode){
     /* The rollback may have destroyed the pPage1->aData value.  So
     ** call btreeGetPage() on page 1 again to make
     ** sure pPage1->aData is set correctly. */
-    if( btreeGetPage(pBt, 1, &pPage1, 0, 0)==SQLITE_OK ){
+    if( btreeGetPage(pBt, 1, &pPage1, 0)==SQLITE_OK ){
       int nPage = get4byte(28+(u8*)pPage1->aData);
       testcase( nPage==0 );
       if( nPage==0 ) sqlite3PagerPagecount(pBt->pPager, &nPage);
@@ -3880,7 +3880,7 @@ static int getOverflowPage(
 
   assert( next==0 || rc==SQLITE_DONE );
   if( rc==SQLITE_OK ){
-    rc = btreeGetPage(pBt, ovfl, &pPage, 0, (ppPage==0));
+    rc = btreeGetPage(pBt, ovfl, &pPage, (ppPage==0) ? PAGER_GET_READONLY : 0);
     assert( rc==SQLITE_OK || pPage==0 );
     if( rc==SQLITE_OK ){
       next = get4byte(pPage->aData);
@@ -4102,7 +4102,7 @@ static int accessPayload(
         {
           DbPage *pDbPage;
           rc = sqlite3PagerAcquire(pBt->pPager, nextPage, &pDbPage,
-              (eOp==0 ? PAGER_ACQUIRE_READONLY : 0)
+              (eOp==0 ? PAGER_GET_READONLY : 0)
           );
           if( rc==SQLITE_OK ){
             aPayload = sqlite3PagerGetData(pDbPage);
@@ -4286,7 +4286,8 @@ static int moveToChild(BtCursor *pCur, u32 newPgno){
   if( pCur->iPage>=(BTCURSOR_MAX_DEPTH-1) ){
     return SQLITE_CORRUPT_BKPT;
   }
-  rc = getAndInitPage(pBt, newPgno, &pNewPage, (pCur->wrFlag==0));
+  rc = getAndInitPage(pBt, newPgno, &pNewPage,
+               pCur->wrFlag==0 ? PAGER_GET_READONLY : 0);
   if( rc ) return rc;
   pCur->apPage[i+1] = pNewPage;
   pCur->aiIdx[i+1] = 0;
@@ -4403,7 +4404,8 @@ static int moveToRoot(BtCursor *pCur){
     pCur->eState = CURSOR_INVALID;
     return SQLITE_OK;
   }else{
-    rc = getAndInitPage(pBt, pCur->pgnoRoot, &pCur->apPage[0], pCur->wrFlag==0);
+    rc = getAndInitPage(pBt, pCur->pgnoRoot, &pCur->apPage[0],
+                        pCur->wrFlag==0 ? PAGER_GET_READONLY : 0);
     if( rc!=SQLITE_OK ){
       pCur->eState = CURSOR_INVALID;
       return rc;
@@ -4798,21 +4800,29 @@ int sqlite3BtreeNext(BtCursor *pCur, int *pRes){
   MemPage *pPage;
 
   assert( cursorHoldsMutex(pCur) );
-  rc = restoreCursorPosition(pCur);
-  if( rc!=SQLITE_OK ){
-    return rc;
-  }
   assert( pRes!=0 );
-  if( CURSOR_INVALID==pCur->eState ){
-    *pRes = 1;
-    return SQLITE_OK;
-  }
-  if( pCur->skipNext>0 ){
-    pCur->skipNext = 0;
-    *pRes = 0;
-    return SQLITE_OK;
+  assert( pCur->skipNext==0 || pCur->eState!=CURSOR_VALID );
+  if( pCur->eState!=CURSOR_VALID ){
+    rc = restoreCursorPosition(pCur);
+    if( rc!=SQLITE_OK ){
+      *pRes = 0;
+      return rc;
+    }
+    if( CURSOR_INVALID==pCur->eState ){
+      *pRes = 1;
+      return SQLITE_OK;
+    }
+    if( pCur->skipNext ){
+      assert( pCur->eState==CURSOR_VALID || pCur->eState==CURSOR_SKIPNEXT );
+      pCur->eState = CURSOR_VALID;
+      if( pCur->skipNext>0 ){
+        pCur->skipNext = 0;
+        *pRes = 0;
+        return SQLITE_OK;
+      }
+      pCur->skipNext = 0;
+    }
   }
-  pCur->skipNext = 0;
 
   pPage = pCur->apPage[pCur->iPage];
   idx = ++pCur->aiIdx[pCur->iPage];
@@ -4830,7 +4840,10 @@ int sqlite3BtreeNext(BtCursor *pCur, int *pRes){
   if( idx>=pPage->nCell ){
     if( !pPage->leaf ){
       rc = moveToChild(pCur, get4byte(&pPage->aData[pPage->hdrOffset+8]));
-      if( rc ) return rc;
+      if( rc ){
+        *pRes = 0;
+        return rc;
+      }
       rc = moveToLeftmost(pCur);
       *pRes = 0;
       return rc;
@@ -4872,21 +4885,32 @@ int sqlite3BtreePrevious(BtCursor *pCur, int *pRes){
   MemPage *pPage;
 
   assert( cursorHoldsMutex(pCur) );
-  rc = restoreCursorPosition(pCur);
-  if( rc!=SQLITE_OK ){
-    return rc;
-  }
+  assert( pRes!=0 );
+  assert( pCur->skipNext==0 || pCur->eState!=CURSOR_VALID );
   pCur->atLast = 0;
-  if( CURSOR_INVALID==pCur->eState ){
-    *pRes = 1;
-    return SQLITE_OK;
-  }
-  if( pCur->skipNext<0 ){
-    pCur->skipNext = 0;
-    *pRes = 0;
-    return SQLITE_OK;
+  if( pCur->eState!=CURSOR_VALID ){
+    if( ALWAYS(pCur->eState>=CURSOR_REQUIRESEEK) ){
+      rc = btreeRestoreCursorPosition(pCur);
+      if( rc!=SQLITE_OK ){
+        *pRes = 0;
+        return rc;
+      }
+    }
+    if( CURSOR_INVALID==pCur->eState ){
+      *pRes = 1;
+      return SQLITE_OK;
+    }
+    if( pCur->skipNext ){
+      assert( pCur->eState==CURSOR_VALID || pCur->eState==CURSOR_SKIPNEXT );
+      pCur->eState = CURSOR_VALID;
+      if( pCur->skipNext<0 ){
+        pCur->skipNext = 0;
+        *pRes = 0;
+        return SQLITE_OK;
+      }
+      pCur->skipNext = 0;
+    }
   }
-  pCur->skipNext = 0;
 
   pPage = pCur->apPage[pCur->iPage];
   assert( pPage->isInit );
@@ -4894,6 +4918,7 @@ int sqlite3BtreePrevious(BtCursor *pCur, int *pRes){
     int idx = pCur->aiIdx[pCur->iPage];
     rc = moveToChild(pCur, get4byte(findCell(pPage, idx)));
     if( rc ){
+      *pRes = 0;
       return rc;
     }
     rc = moveToRightmost(pCur);
@@ -5017,7 +5042,7 @@ static int allocateBtreePage(
       if( iTrunk>mxPage ){
         rc = SQLITE_CORRUPT_BKPT;
       }else{
-        rc = btreeGetPage(pBt, iTrunk, &pTrunk, 0, 0);
+        rc = btreeGetPage(pBt, iTrunk, &pTrunk, 0);
       }
       if( rc ){
         pTrunk = 0;
@@ -5081,7 +5106,7 @@ static int allocateBtreePage(
             goto end_allocate_page;
           }
           testcase( iNewTrunk==mxPage );
-          rc = btreeGetPage(pBt, iNewTrunk, &pNewTrunk, 0, 0);
+          rc = btreeGetPage(pBt, iNewTrunk, &pNewTrunk, 0);
           if( rc!=SQLITE_OK ){
             goto end_allocate_page;
           }
@@ -5160,8 +5185,8 @@ static int allocateBtreePage(
             memcpy(&aData[8+closest*4], &aData[4+k*4], 4);
           }
           put4byte(&aData[4], k-1);
-          noContent = !btreeGetHasContent(pBt, *pPgno);
-          rc = btreeGetPage(pBt, *pPgno, ppPage, noContent, 0);
+          noContent = !btreeGetHasContent(pBt, *pPgno) ? PAGER_GET_NOCONTENT : 0;
+          rc = btreeGetPage(pBt, *pPgno, ppPage, noContent);
           if( rc==SQLITE_OK ){
             rc = sqlite3PagerWrite((*ppPage)->pDbPage);
             if( rc!=SQLITE_OK ){
@@ -5193,7 +5218,7 @@ static int allocateBtreePage(
     ** here are confined to those pages that lie between the end of the
     ** database image and the end of the database file.
     */
-    int bNoContent = (0==IfNotOmitAV(pBt->bDoTruncate));
+    int bNoContent = (0==IfNotOmitAV(pBt->bDoTruncate)) ? PAGER_GET_NOCONTENT : 0;
 
     rc = sqlite3PagerWrite(pBt->pPage1->pDbPage);
     if( rc ) return rc;
@@ -5209,7 +5234,7 @@ static int allocateBtreePage(
       MemPage *pPg = 0;
       TRACE(("ALLOCATE: %d from end of file (pointer-map page)\n", pBt->nPage));
       assert( pBt->nPage!=PENDING_BYTE_PAGE(pBt) );
-      rc = btreeGetPage(pBt, pBt->nPage, &pPg, bNoContent, 0);
+      rc = btreeGetPage(pBt, pBt->nPage, &pPg, bNoContent);
       if( rc==SQLITE_OK ){
         rc = sqlite3PagerWrite(pPg->pDbPage);
         releasePage(pPg);
@@ -5223,7 +5248,7 @@ static int allocateBtreePage(
     *pPgno = pBt->nPage;
 
     assert( *pPgno!=PENDING_BYTE_PAGE(pBt) );
-    rc = btreeGetPage(pBt, *pPgno, ppPage, bNoContent, 0);
+    rc = btreeGetPage(pBt, *pPgno, ppPage, bNoContent);
     if( rc ) return rc;
     rc = sqlite3PagerWrite((*ppPage)->pDbPage);
     if( rc!=SQLITE_OK ){
@@ -5291,7 +5316,7 @@ static int freePage2(BtShared *pBt, MemPage *pMemPage, Pgno iPage){
     /* If the secure_delete option is enabled, then
     ** always fully overwrite deleted information with zeros.
     */
-    if( (!pPage && ((rc = btreeGetPage(pBt, iPage, &pPage, 0, 0))!=0) )
+    if( (!pPage && ((rc = btreeGetPage(pBt, iPage, &pPage, 0))!=0) )
      ||            ((rc = sqlite3PagerWrite(pPage->pDbPage))!=0)
     ){
       goto freepage_out;
@@ -5318,7 +5343,7 @@ static int freePage2(BtShared *pBt, MemPage *pMemPage, Pgno iPage){
     u32 nLeaf;                /* Initial number of leaf cells on trunk page */
 
     iTrunk = get4byte(&pPage1->aData[32]);
-    rc = btreeGetPage(pBt, iTrunk, &pTrunk, 0, 0);
+    rc = btreeGetPage(pBt, iTrunk, &pTrunk, 0);
     if( rc!=SQLITE_OK ){
       goto freepage_out;
     }
@@ -5364,7 +5389,7 @@ static int freePage2(BtShared *pBt, MemPage *pMemPage, Pgno iPage){
   ** first trunk in the free-list is full. Either way, the page being freed
   ** will become the new first trunk page in the free-list.
   */
-  if( pPage==0 && SQLITE_OK!=(rc = btreeGetPage(pBt, iPage, &pPage, 0, 0)) ){
+  if( pPage==0 && SQLITE_OK!=(rc = btreeGetPage(pBt, iPage, &pPage, 0)) ){
     goto freepage_out;
   }
   rc = sqlite3PagerWrite(pPage->pDbPage);
@@ -7263,7 +7288,7 @@ static int btreeCreateTable(Btree *p, int *piTable, int createTabFlags){
       }
 
       /* Move the page currently at pgnoRoot to pgnoMove. */
-      rc = btreeGetPage(pBt, pgnoRoot, &pRoot, 0, 0);
+      rc = btreeGetPage(pBt, pgnoRoot, &pRoot, 0);
       if( rc!=SQLITE_OK ){
         return rc;
       }
@@ -7284,7 +7309,7 @@ static int btreeCreateTable(Btree *p, int *piTable, int createTabFlags){
       if( rc!=SQLITE_OK ){
         return rc;
       }
-      rc = btreeGetPage(pBt, pgnoRoot, &pRoot, 0, 0);
+      rc = btreeGetPage(pBt, pgnoRoot, &pRoot, 0);
       if( rc!=SQLITE_OK ){
         return rc;
       }
@@ -7462,7 +7487,7 @@ static int btreeDropTable(Btree *p, Pgno iTable, int *piMoved){
     return SQLITE_LOCKED_SHAREDCACHE;
   }
 
-  rc = btreeGetPage(pBt, (Pgno)iTable, &pPage, 0, 0);
+  rc = btreeGetPage(pBt, (Pgno)iTable, &pPage, 0);
   if( rc ) return rc;
   rc = sqlite3BtreeClearTable(p, iTable, 0);
   if( rc ){
@@ -7497,7 +7522,7 @@ static int btreeDropTable(Btree *p, Pgno iTable, int *piMoved){
         */
         MemPage *pMove;
         releasePage(pPage);
-        rc = btreeGetPage(pBt, maxRootPgno, &pMove, 0, 0);
+        rc = btreeGetPage(pBt, maxRootPgno, &pMove, 0);
         if( rc!=SQLITE_OK ){
           return rc;
         }
@@ -7507,7 +7532,7 @@ static int btreeDropTable(Btree *p, Pgno iTable, int *piMoved){
           return rc;
         }
         pMove = 0;
-        rc = btreeGetPage(pBt, maxRootPgno, &pMove, 0, 0);
+        rc = btreeGetPage(pBt, maxRootPgno, &pMove, 0);
         freePage(pMove, &rc);
         releasePage(pMove);
         if( rc!=SQLITE_OK ){
@@ -7722,7 +7747,7 @@ static void checkAppendMsg(
   }
   sqlite3VXPrintf(&pCheck->errMsg, 1, zFormat, ap);
   va_end(ap);
-  if( pCheck->errMsg.mallocFailed ){
+  if( pCheck->errMsg.accError==STRACCUM_NOMEM ){
     pCheck->mallocFailed = 1;
   }
 }
@@ -7919,7 +7944,7 @@ static int checkTreePage(
   usableSize = pBt->usableSize;
   if( iPage==0 ) return 0;
   if( checkRef(pCheck, iPage, zParentContext) ) return 0;
-  if( (rc = btreeGetPage(pBt, (Pgno)iPage, &pPage, 0, 0))!=0 ){
+  if( (rc = btreeGetPage(pBt, (Pgno)iPage, &pPage, 0))!=0 ){
     checkAppendMsg(pCheck, zContext,
        "unable to get the page. error code=%d", rc);
     return 0;
diff --git a/lib/libsqlite3/src/btree.h b/lib/libsqlite3/src/btree.h
index ace0f8cd217..33b3ed1f089 100644
--- a/lib/libsqlite3/src/btree.h
+++ b/lib/libsqlite3/src/btree.h
@@ -64,7 +64,7 @@ int sqlite3BtreeOpen(
 int sqlite3BtreeClose(Btree*);
 int sqlite3BtreeSetCacheSize(Btree*,int);
 int sqlite3BtreeSetMmapLimit(Btree*,sqlite3_int64);
-int sqlite3BtreeSetSafetyLevel(Btree*,int,int,int);
+int sqlite3BtreeSetPagerFlags(Btree*,unsigned);
 int sqlite3BtreeSyncDisabled(Btree*);
 int sqlite3BtreeSetPageSize(Btree *p, int nPagesize, int nReserve, int eFix);
 int sqlite3BtreeGetPageSize(Btree*);
diff --git a/lib/libsqlite3/src/btreeInt.h b/lib/libsqlite3/src/btreeInt.h
index ce3c5493f8c..60da24d90c5 100644
--- a/lib/libsqlite3/src/btreeInt.h
+++ b/lib/libsqlite3/src/btreeInt.h
@@ -520,14 +520,19 @@ struct BtCursor {
 /*
 ** Potential values for BtCursor.eState.
 **
-** CURSOR_VALID:
-**   Cursor points to a valid entry. getPayload() etc. may be called.
-**
 ** CURSOR_INVALID:
 **   Cursor does not point to a valid entry. This can happen (for example) 
 **   because the table is empty or because BtreeCursorFirst() has not been
 **   called.
 **
+** CURSOR_VALID:
+**   Cursor points to a valid entry. getPayload() etc. may be called.
+**
+** CURSOR_SKIPNEXT:
+**   Cursor is valid except that the Cursor.skipNext field is non-zero
+**   indicating that the next sqlite3BtreeNext() or sqlite3BtreePrevious()
+**   operation should be a no-op.
+**
 ** CURSOR_REQUIRESEEK:
 **   The table that this cursor was opened on still exists, but has been 
 **   modified since the cursor was last used. The cursor position is saved
@@ -544,8 +549,9 @@ struct BtCursor {
 */
 #define CURSOR_INVALID           0
 #define CURSOR_VALID             1
-#define CURSOR_REQUIRESEEK       2
-#define CURSOR_FAULT             3
+#define CURSOR_SKIPNEXT          2
+#define CURSOR_REQUIRESEEK       3
+#define CURSOR_FAULT             4
 
 /* 
 ** The database page the PENDING_BYTE occupies. This page is never used.
diff --git a/lib/libsqlite3/src/build.c b/lib/libsqlite3/src/build.c
index 3c91cdcfdb7..02390173896 100644
--- a/lib/libsqlite3/src/build.c
+++ b/lib/libsqlite3/src/build.c
@@ -382,6 +382,7 @@ static void freeIndex(sqlite3 *db, Index *p){
 #ifndef SQLITE_OMIT_ANALYZE
   sqlite3DeleteIndexSamples(db, p);
 #endif
+  sqlite3ExprDelete(db, p->pPartIdxWhere);
   sqlite3DbFree(db, p->zColAff);
   sqlite3DbFree(db, p);
 }
@@ -1225,7 +1226,8 @@ void sqlite3AddPrimaryKey(
 #endif
   }else{
     Index *p;
-    p = sqlite3CreateIndex(pParse, 0, 0, 0, pList, onError, 0, 0, sortOrder, 0);
+    p = sqlite3CreateIndex(pParse, 0, 0, 0, pList, onError, 0,
+                           0, sortOrder, 0);
     if( p ){
       p->autoIndex = 2;
     }
@@ -1276,6 +1278,7 @@ void sqlite3AddCollateType(Parse *pParse, Token *pToken){
 
   if( sqlite3LocateCollSeq(pParse, zColl) ){
     Index *pIdx;
+    sqlite3DbFree(db, p->aCol[i].zColl);
     p->aCol[i].zColl = zColl;
   
     /* If the column is declared as "<name> PRIMARY KEY COLLATE <type>",
@@ -1519,26 +1522,7 @@ void sqlite3EndTable(
   /* Resolve names in all CHECK constraint expressions.
   */
   if( p->pCheck ){
-    SrcList sSrc;                   /* Fake SrcList for pParse->pNewTable */
-    NameContext sNC;                /* Name context for pParse->pNewTable */
-    ExprList *pList;                /* List of all CHECK constraints */
-    int i;                          /* Loop counter */
-
-    memset(&sNC, 0, sizeof(sNC));
-    memset(&sSrc, 0, sizeof(sSrc));
-    sSrc.nSrc = 1;
-    sSrc.a[0].zName = p->zName;
-    sSrc.a[0].pTab = p;
-    sSrc.a[0].iCursor = -1;
-    sNC.pParse = pParse;
-    sNC.pSrcList = &sSrc;
-    sNC.ncFlags = NC_IsCheck;
-    pList = p->pCheck;
-    for(i=0; i<pList->nExpr; i++){
-      if( sqlite3ResolveExprNames(&sNC, pList->a[i].pExpr) ){
-        return;
-      }
-    }
+    sqlite3ResolveSelfReference(pParse, p, NC_IsCheck, 0, p->pCheck);
   }
 #endif /* !defined(SQLITE_OMIT_CHECK) */
 
@@ -2390,6 +2374,7 @@ static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
   int addr1;                     /* Address of top of loop */
   int addr2;                     /* Address to jump to for next iteration */
   int tnum;                      /* Root page of index */
+  int iPartIdxLabel;             /* Jump to this label to skip a row */
   Vdbe *v;                       /* Generate code into this virtual machine */
   KeyInfo *pKey;                 /* KeyInfo for index */
   int regRecord;                 /* Register holding assemblied index record */
@@ -2429,8 +2414,9 @@ static void sqlite3RefillIndex(Parse *pParse, Index *pIndex, int memRootPage){
   addr1 = sqlite3VdbeAddOp2(v, OP_Rewind, iTab, 0);
   regRecord = sqlite3GetTempReg(pParse);
 
-  sqlite3GenerateIndexKey(pParse, pIndex, iTab, regRecord, 1);
+  sqlite3GenerateIndexKey(pParse, pIndex, iTab, regRecord, 1, &iPartIdxLabel);
   sqlite3VdbeAddOp2(v, OP_SorterInsert, iSorter, regRecord);
+  sqlite3VdbeResolveLabel(v, iPartIdxLabel);
   sqlite3VdbeAddOp2(v, OP_Next, iTab, addr1+1);
   sqlite3VdbeJumpHere(v, addr1);
   addr1 = sqlite3VdbeAddOp2(v, OP_SorterSort, iSorter, 0);
@@ -2481,7 +2467,7 @@ Index *sqlite3CreateIndex(
   ExprList *pList,   /* A list of columns to be indexed */
   int onError,       /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
   Token *pStart,     /* The CREATE token that begins this statement */
-  Token *pEnd,       /* The ")" that closes the CREATE INDEX statement */
+  Expr *pPIWhere,    /* WHERE clause for partial indices */
   int sortOrder,     /* Sort order of primary key when pList==NULL */
   int ifNotExist     /* Omit error if index already exists */
 ){
@@ -2503,7 +2489,6 @@ Index *sqlite3CreateIndex(
   int nExtra = 0;
   char *zExtra;
 
-  assert( pStart==0 || pEnd!=0 ); /* pEnd must be non-NULL if pStart is */
   assert( pParse->nErr==0 );      /* Never called with prior errors */
   if( db->mallocFailed || IN_DECLARE_VTAB ){
     goto exit_create_index;
@@ -2549,7 +2534,12 @@ Index *sqlite3CreateIndex(
     pTab = sqlite3LocateTableItem(pParse, 0, &pTblName->a[0]);
     assert( db->mallocFailed==0 || pTab==0 );
     if( pTab==0 ) goto exit_create_index;
-    assert( db->aDb[iDb].pSchema==pTab->pSchema );
+    if( iDb==1 && db->aDb[iDb].pSchema!=pTab->pSchema ){
+      sqlite3ErrorMsg(pParse, 
+           "cannot create a TEMP index on non-TEMP table \"%s\"",
+           pTab->zName);
+      goto exit_create_index;
+    }
   }else{
     assert( pName==0 );
     assert( pStart==0 );
@@ -2695,8 +2685,14 @@ Index *sqlite3CreateIndex(
   pIndex->pTable = pTab;
   pIndex->nColumn = pList->nExpr;
   pIndex->onError = (u8)onError;
+  pIndex->uniqNotNull = onError==OE_Abort;
   pIndex->autoIndex = (u8)(pName==0);
   pIndex->pSchema = db->aDb[iDb].pSchema;
+  if( pPIWhere ){
+    sqlite3ResolveSelfReference(pParse, pTab, NC_PartIdx, pPIWhere, 0);
+    pIndex->pPartIdxWhere = pPIWhere;
+    pPIWhere = 0;
+  }
   assert( sqlite3SchemaMutexHeld(db, iDb, 0) );
 
   /* Check to see if we should honor DESC requests on index columns
@@ -2753,6 +2749,7 @@ Index *sqlite3CreateIndex(
     pIndex->azColl[i] = zColl;
     requestedSortOrder = pListItem->sortOrder & sortOrderMask;
     pIndex->aSortOrder[i] = (u8)requestedSortOrder;
+    if( pTab->aCol[j].notNull==0 ) pIndex->uniqNotNull = 0;
   }
   sqlite3DefaultRowEst(pIndex);
 
@@ -2851,7 +2848,7 @@ Index *sqlite3CreateIndex(
   ** has just been created, it contains no data and the index initialization
   ** step can be skipped.
   */
-  else{ /* if( db->init.busy==0 ) */
+  else if( pParse->nErr==0 ){
     Vdbe *v;
     char *zStmt;
     int iMem = ++pParse->nMem;
@@ -2869,12 +2866,11 @@ Index *sqlite3CreateIndex(
     ** the zStmt variable
     */
     if( pStart ){
-      assert( pEnd!=0 );
+      int n = (int)(pParse->sLastToken.z - pName->z) + pParse->sLastToken.n;
+      if( pName->z[n-1]==';' ) n--;
       /* A named index with an explicit CREATE INDEX statement */
       zStmt = sqlite3MPrintf(db, "CREATE%s INDEX %.*s",
-        onError==OE_None ? "" : " UNIQUE",
-        (int)(pEnd->z - pName->z) + 1,
-        pName->z);
+        onError==OE_None ? "" : " UNIQUE", n, pName->z);
     }else{
       /* An automatic index created by a PRIMARY KEY or UNIQUE constraint */
       /* zStmt = sqlite3MPrintf(""); */
@@ -2930,10 +2926,8 @@ Index *sqlite3CreateIndex(
 
   /* Clean up before exiting */
 exit_create_index:
-  if( pIndex ){
-    sqlite3DbFree(db, pIndex->zColAff);
-    sqlite3DbFree(db, pIndex);
-  }
+  if( pIndex ) freeIndex(db, pIndex);
+  sqlite3ExprDelete(db, pPIWhere);
   sqlite3ExprListDelete(db, pList);
   sqlite3SrcListDelete(db, pTblName);
   sqlite3DbFree(db, zName);
@@ -3184,7 +3178,7 @@ SrcList *sqlite3SrcListEnlarge(
     }
     pSrc = pNew;
     nGot = (sqlite3DbMallocSize(db, pNew) - sizeof(*pSrc))/sizeof(pSrc->a[0])+1;
-    pSrc->nAlloc = (u16)nGot;
+    pSrc->nAlloc = (u8)nGot;
   }
 
   /* Move existing slots that come after the newly inserted slots
@@ -3192,7 +3186,7 @@ SrcList *sqlite3SrcListEnlarge(
   for(i=pSrc->nSrc-1; i>=iStart; i--){
     pSrc->a[i+nExtra] = pSrc->a[i];
   }
-  pSrc->nSrc += (i16)nExtra;
+  pSrc->nSrc += (i8)nExtra;
 
   /* Zero the newly allocated slots */
   memset(&pSrc->a[iStart], 0, sizeof(pSrc->a[0])*nExtra);
@@ -3811,25 +3805,20 @@ void sqlite3Reindex(Parse *pParse, Token *pName1, Token *pName2){
 KeyInfo *sqlite3IndexKeyinfo(Parse *pParse, Index *pIdx){
   int i;
   int nCol = pIdx->nColumn;
-  int nBytes = sizeof(KeyInfo) + (nCol-1)*sizeof(CollSeq*) + nCol;
-  sqlite3 *db = pParse->db;
-  KeyInfo *pKey = (KeyInfo *)sqlite3DbMallocZero(db, nBytes);
+  KeyInfo *pKey;
 
+  pKey = sqlite3KeyInfoAlloc(pParse->db, nCol);
   if( pKey ){
-    pKey->db = pParse->db;
-    pKey->aSortOrder = (u8 *)&(pKey->aColl[nCol]);
-    assert( &pKey->aSortOrder[nCol]==&(((u8 *)pKey)[nBytes]) );
     for(i=0; i<nCol; i++){
       char *zColl = pIdx->azColl[i];
       assert( zColl );
       pKey->aColl[i] = sqlite3LocateCollSeq(pParse, zColl);
       pKey->aSortOrder[i] = pIdx->aSortOrder[i];
     }
-    pKey->nField = (u16)nCol;
   }
 
   if( pParse->nErr ){
-    sqlite3DbFree(db, pKey);
+    sqlite3DbFree(pParse->db, pKey);
     pKey = 0;
   }
   return pKey;
diff --git a/lib/libsqlite3/src/delete.c b/lib/libsqlite3/src/delete.c
index 634e115563a..af64afc65cc 100644
--- a/lib/libsqlite3/src/delete.c
+++ b/lib/libsqlite3/src/delete.c
@@ -591,11 +591,14 @@ void sqlite3GenerateRowIndexDelete(
   int i;
   Index *pIdx;
   int r1;
+  int iPartIdxLabel;
+  Vdbe *v = pParse->pVdbe;
 
   for(i=1, pIdx=pTab->pIndex; pIdx; i++, pIdx=pIdx->pNext){
     if( aRegIdx!=0 && aRegIdx[i-1]==0 ) continue;
-    r1 = sqlite3GenerateIndexKey(pParse, pIdx, iCur, 0, 0);
-    sqlite3VdbeAddOp3(pParse->pVdbe, OP_IdxDelete, iCur+i, r1,pIdx->nColumn+1);
+    r1 = sqlite3GenerateIndexKey(pParse, pIdx, iCur, 0, 0, &iPartIdxLabel);
+    sqlite3VdbeAddOp3(v, OP_IdxDelete, iCur+i, r1, pIdx->nColumn+1);
+    sqlite3VdbeResolveLabel(v, iPartIdxLabel);
   }
 }
 
@@ -609,13 +612,21 @@ void sqlite3GenerateRowIndexDelete(
 ** registers that holds the elements of the index key.  The
 ** block of registers has already been deallocated by the time
 ** this routine returns.
+**
+** If *piPartIdxLabel is not NULL, fill it in with a label and jump
+** to that label if pIdx is a partial index that should be skipped.
+** A partial index should be skipped if its WHERE clause evaluates
+** to false or null.  If pIdx is not a partial index, *piPartIdxLabel
+** will be set to zero which is an empty label that is ignored by
+** sqlite3VdbeResolveLabel().
 */
 int sqlite3GenerateIndexKey(
-  Parse *pParse,     /* Parsing context */
-  Index *pIdx,       /* The index for which to generate a key */
-  int iCur,          /* Cursor number for the pIdx->pTable table */
-  int regOut,        /* Write the new index key to this register */
-  int doMakeRec      /* Run the OP_MakeRecord instruction if true */
+  Parse *pParse,       /* Parsing context */
+  Index *pIdx,         /* The index for which to generate a key */
+  int iCur,            /* Cursor number for the pIdx->pTable table */
+  int regOut,          /* Write the new index key to this register */
+  int doMakeRec,       /* Run the OP_MakeRecord instruction if true */
+  int *piPartIdxLabel  /* OUT: Jump to this label to skip partial index */
 ){
   Vdbe *v = pParse->pVdbe;
   int j;
@@ -623,6 +634,16 @@ int sqlite3GenerateIndexKey(
   int regBase;
   int nCol;
 
+  if( piPartIdxLabel ){
+    if( pIdx->pPartIdxWhere ){
+      *piPartIdxLabel = sqlite3VdbeMakeLabel(v);
+      pParse->iPartIdxTab = iCur;
+      sqlite3ExprIfFalse(pParse, pIdx->pPartIdxWhere, *piPartIdxLabel, 
+                         SQLITE_JUMPIFNULL);
+    }else{
+      *piPartIdxLabel = 0;
+    }
+  }
   nCol = pIdx->nColumn;
   regBase = sqlite3GetTempRange(pParse, nCol+1);
   sqlite3VdbeAddOp2(v, OP_Rowid, iCur, regBase+nCol);
diff --git a/lib/libsqlite3/src/expr.c b/lib/libsqlite3/src/expr.c
index 660397e078a..dd4f5de15fc 100644
--- a/lib/libsqlite3/src/expr.c
+++ b/lib/libsqlite3/src/expr.c
@@ -114,8 +114,7 @@ CollSeq *sqlite3ExprCollSeq(Parse *pParse, Expr *pExpr){
       p = p->pLeft;
       continue;
     }
-    assert( op!=TK_REGISTER || p->op2!=TK_COLLATE );
-    if( op==TK_COLLATE ){
+    if( op==TK_COLLATE || (op==TK_REGISTER && p->op2==TK_COLLATE) ){
       pColl = sqlite3GetCollSeq(pParse, ENC(db), 0, p->u.zToken);
       break;
     }
@@ -920,6 +919,7 @@ ExprList *sqlite3ExprListDup(sqlite3 *db, ExprList *p, int flags){
     pItem->zSpan = sqlite3DbStrDup(db, pOldItem->zSpan);
     pItem->sortOrder = pOldItem->sortOrder;
     pItem->done = 0;
+    pItem->bSpanIsTab = pOldItem->bSpanIsTab;
     pItem->iOrderByCol = pOldItem->iOrderByCol;
     pItem->iAlias = pOldItem->iAlias;
   }
@@ -1278,6 +1278,7 @@ int sqlite3ExprIsInteger(Expr *p, int *pValue){
     case TK_UMINUS: {
       int v;
       if( sqlite3ExprIsInteger(p->pLeft, &v) ){
+        assert( v!=-2147483648 );
         *pValue = -v;
         rc = 1;
       }
@@ -1596,15 +1597,15 @@ int sqlite3FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){
     /* Could not found an existing table or index to use as the RHS b-tree.
     ** We will have to generate an ephemeral table to do the job.
     */
-    double savedNQueryLoop = pParse->nQueryLoop;
+    u32 savedNQueryLoop = pParse->nQueryLoop;
     int rMayHaveNull = 0;
     eType = IN_INDEX_EPH;
     if( prNotFound ){
       *prNotFound = rMayHaveNull = ++pParse->nMem;
       sqlite3VdbeAddOp2(v, OP_Null, 0, *prNotFound);
     }else{
-      testcase( pParse->nQueryLoop>(double)1 );
-      pParse->nQueryLoop = (double)1;
+      testcase( pParse->nQueryLoop>0 );
+      pParse->nQueryLoop = 0;
       if( pX->pLeft->iColumn<0 && !ExprHasAnyProperty(pX, EP_xIsSelect) ){
         eType = IN_INDEX_ROWID;
       }
@@ -1646,7 +1647,7 @@ int sqlite3FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){
 **
 ** If rMayHaveNull is zero, that means that the subquery is being used
 ** for membership testing only.  There is no need to initialize any
-** registers to indicate the presense or absence of NULLs on the RHS.
+** registers to indicate the presence or absence of NULLs on the RHS.
 **
 ** For a SELECT or EXISTS operator, return the register that holds the
 ** result.  For IN operators or if an error occurs, the return value is 0.
@@ -1691,10 +1692,9 @@ int sqlite3CodeSubselect(
   switch( pExpr->op ){
     case TK_IN: {
       char affinity;              /* Affinity of the LHS of the IN */
-      KeyInfo keyInfo;            /* Keyinfo for the generated table */
-      static u8 sortOrder = 0;    /* Fake aSortOrder for keyInfo */
       int addr;                   /* Address of OP_OpenEphemeral instruction */
       Expr *pLeft = pExpr->pLeft; /* the LHS of the IN operator */
+      KeyInfo *pKeyInfo = 0;      /* Key information */
 
       if( rMayHaveNull ){
         sqlite3VdbeAddOp2(v, OP_Null, 0, rMayHaveNull);
@@ -1718,9 +1718,7 @@ int sqlite3CodeSubselect(
       pExpr->iTable = pParse->nTab++;
       addr = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, pExpr->iTable, !isRowid);
       if( rMayHaveNull==0 ) sqlite3VdbeChangeP5(v, BTREE_UNORDERED);
-      memset(&keyInfo, 0, sizeof(keyInfo));
-      keyInfo.nField = 1;
-      keyInfo.aSortOrder = &sortOrder;
+      pKeyInfo = isRowid ? 0 : sqlite3KeyInfoAlloc(pParse->db, 1);
 
       if( ExprHasProperty(pExpr, EP_xIsSelect) ){
         /* Case 1:     expr IN (SELECT ...)
@@ -1736,14 +1734,17 @@ int sqlite3CodeSubselect(
         dest.affSdst = (u8)affinity;
         assert( (pExpr->iTable&0x0000FFFF)==pExpr->iTable );
         pExpr->x.pSelect->iLimit = 0;
+        testcase( pKeyInfo==0 ); /* Caused by OOM in sqlite3KeyInfoAlloc() */
         if( sqlite3Select(pParse, pExpr->x.pSelect, &dest) ){
+          sqlite3DbFree(pParse->db, pKeyInfo);
           return 0;
         }
         pEList = pExpr->x.pSelect->pEList;
-        if( ALWAYS(pEList!=0 && pEList->nExpr>0) ){ 
-          keyInfo.aColl[0] = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft,
-              pEList->a[0].pExpr);
-        }
+        assert( pKeyInfo!=0 ); /* OOM will cause exit after sqlite3Select() */
+        assert( pEList!=0 );
+        assert( pEList->nExpr>0 );
+        pKeyInfo->aColl[0] = sqlite3BinaryCompareCollSeq(pParse, pExpr->pLeft,
+                                                         pEList->a[0].pExpr);
       }else if( ALWAYS(pExpr->x.pList!=0) ){
         /* Case 2:     expr IN (exprlist)
         **
@@ -1760,8 +1761,9 @@ int sqlite3CodeSubselect(
         if( !affinity ){
           affinity = SQLITE_AFF_NONE;
         }
-        keyInfo.aColl[0] = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
-        keyInfo.aSortOrder = &sortOrder;
+        if( pKeyInfo ){
+          pKeyInfo->aColl[0] = sqlite3ExprCollSeq(pParse, pExpr->pLeft);
+        }
 
         /* Loop through each expression in <exprlist>. */
         r1 = sqlite3GetTempReg(pParse);
@@ -1800,8 +1802,8 @@ int sqlite3CodeSubselect(
         sqlite3ReleaseTempReg(pParse, r1);
         sqlite3ReleaseTempReg(pParse, r2);
       }
-      if( !isRowid ){
-        sqlite3VdbeChangeP4(v, addr, (void *)&keyInfo, P4_KEYINFO);
+      if( pKeyInfo ){
+        sqlite3VdbeChangeP4(v, addr, (void *)pKeyInfo, P4_KEYINFO_HANDOFF);
       }
       break;
     }
@@ -2361,15 +2363,20 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
       /* Otherwise, fall thru into the TK_COLUMN case */
     }
     case TK_COLUMN: {
-      if( pExpr->iTable<0 ){
-        /* This only happens when coding check constraints */
-        assert( pParse->ckBase>0 );
-        inReg = pExpr->iColumn + pParse->ckBase;
-      }else{
-        inReg = sqlite3ExprCodeGetColumn(pParse, pExpr->pTab,
-                                 pExpr->iColumn, pExpr->iTable, target,
-                                 pExpr->op2);
+      int iTab = pExpr->iTable;
+      if( iTab<0 ){
+        if( pParse->ckBase>0 ){
+          /* Generating CHECK constraints or inserting into partial index */
+          inReg = pExpr->iColumn + pParse->ckBase;
+          break;
+        }else{
+          /* Deleting from a partial index */
+          iTab = pParse->iPartIdxTab;
+        }
       }
+      inReg = sqlite3ExprCodeGetColumn(pParse, pExpr->pTab,
+                               pExpr->iColumn, iTab, target,
+                               pExpr->op2);
       break;
     }
     case TK_INTEGER: {
@@ -3497,6 +3504,7 @@ static void exprCodeBetween(
   compRight.pLeft = &exprX;
   compRight.pRight = pExpr->x.pList->a[1].pExpr;
   exprX.iTable = sqlite3ExprCodeTemp(pParse, &exprX, &regFree1);
+  exprX.op2 = exprX.op;
   exprX.op = TK_REGISTER;
   if( jumpIfTrue ){
     sqlite3ExprIfTrue(pParse, &exprAnd, dest, jumpIfNull);
@@ -3792,6 +3800,12 @@ void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
 ** by a COLLATE operator at the top level.  Return 2 if there are differences
 ** other than the top-level COLLATE operator.
 **
+** If any subelement of pB has Expr.iTable==(-1) then it is allowed
+** to compare equal to an equivalent element in pA with Expr.iTable==iTab.
+**
+** The pA side might be using TK_REGISTER.  If that is the case and pB is
+** not using TK_REGISTER but is otherwise equivalent, then still return 0.
+**
 ** Sometimes this routine will return 2 even if the two expressions
 ** really are equivalent.  If we cannot prove that the expressions are
 ** identical, we return 2 just to be safe.  So if this routine
@@ -3802,7 +3816,7 @@ void sqlite3ExprIfFalse(Parse *pParse, Expr *pExpr, int dest, int jumpIfNull){
 ** just might result in some slightly slower code.  But returning
 ** an incorrect 0 or 1 could lead to a malfunction.
 */
-int sqlite3ExprCompare(Expr *pA, Expr *pB){
+int sqlite3ExprCompare(Expr *pA, Expr *pB, int iTab){
   if( pA==0||pB==0 ){
     return pB==pA ? 0 : 2;
   }
@@ -3812,19 +3826,22 @@ int sqlite3ExprCompare(Expr *pA, Expr *pB){
     return 2;
   }
   if( (pA->flags & EP_Distinct)!=(pB->flags & EP_Distinct) ) return 2;
-  if( pA->op!=pB->op ){
-    if( pA->op==TK_COLLATE && sqlite3ExprCompare(pA->pLeft, pB)<2 ){
+  if( pA->op!=pB->op && (pA->op!=TK_REGISTER || pA->op2!=pB->op) ){
+    if( pA->op==TK_COLLATE && sqlite3ExprCompare(pA->pLeft, pB, iTab)<2 ){
       return 1;
     }
-    if( pB->op==TK_COLLATE && sqlite3ExprCompare(pA, pB->pLeft)<2 ){
+    if( pB->op==TK_COLLATE && sqlite3ExprCompare(pA, pB->pLeft, iTab)<2 ){
       return 1;
     }
     return 2;
   }
-  if( sqlite3ExprCompare(pA->pLeft, pB->pLeft) ) return 2;
-  if( sqlite3ExprCompare(pA->pRight, pB->pRight) ) return 2;
-  if( sqlite3ExprListCompare(pA->x.pList, pB->x.pList) ) return 2;
-  if( pA->iTable!=pB->iTable || pA->iColumn!=pB->iColumn ) return 2;
+  if( sqlite3ExprCompare(pA->pLeft, pB->pLeft, iTab) ) return 2;
+  if( sqlite3ExprCompare(pA->pRight, pB->pRight, iTab) ) return 2;
+  if( sqlite3ExprListCompare(pA->x.pList, pB->x.pList, iTab) ) return 2;
+  if( pA->iColumn!=pB->iColumn ) return 2;
+  if( pA->iTable!=pB->iTable 
+   && pA->op!=TK_REGISTER
+   && (pA->iTable!=iTab || NEVER(pB->iTable>=0)) ) return 2;
   if( ExprHasProperty(pA, EP_IntValue) ){
     if( !ExprHasProperty(pB, EP_IntValue) || pA->u.iValue!=pB->u.iValue ){
       return 2;
@@ -3842,6 +3859,9 @@ int sqlite3ExprCompare(Expr *pA, Expr *pB){
 ** Compare two ExprList objects.  Return 0 if they are identical and 
 ** non-zero if they differ in any way.
 **
+** If any subelement of pB has Expr.iTable==(-1) then it is allowed
+** to compare equal to an equivalent element in pA with Expr.iTable==iTab.
+**
 ** This routine might return non-zero for equivalent ExprLists.  The
 ** only consequence will be disabled optimizations.  But this routine
 ** must never return 0 if the two ExprList objects are different, or
@@ -3850,7 +3870,7 @@ int sqlite3ExprCompare(Expr *pA, Expr *pB){
 ** Two NULL pointers are considered to be the same.  But a NULL pointer
 ** always differs from a non-NULL pointer.
 */
-int sqlite3ExprListCompare(ExprList *pA, ExprList *pB){
+int sqlite3ExprListCompare(ExprList *pA, ExprList *pB, int iTab){
   int i;
   if( pA==0 && pB==0 ) return 0;
   if( pA==0 || pB==0 ) return 1;
@@ -3859,7 +3879,46 @@ int sqlite3ExprListCompare(ExprList *pA, ExprList *pB){
     Expr *pExprA = pA->a[i].pExpr;
     Expr *pExprB = pB->a[i].pExpr;
     if( pA->a[i].sortOrder!=pB->a[i].sortOrder ) return 1;
-    if( sqlite3ExprCompare(pExprA, pExprB) ) return 1;
+    if( sqlite3ExprCompare(pExprA, pExprB, iTab) ) return 1;
+  }
+  return 0;
+}
+
+/*
+** Return true if we can prove the pE2 will always be true if pE1 is
+** true.  Return false if we cannot complete the proof or if pE2 might
+** be false.  Examples:
+**
+**     pE1: x==5       pE2: x==5             Result: true
+**     pE1: x>0        pE2: x==5             Result: false
+**     pE1: x=21       pE2: x=21 OR y=43     Result: true
+**     pE1: x!=123     pE2: x IS NOT NULL    Result: true
+**     pE1: x!=?1      pE2: x IS NOT NULL    Result: true
+**     pE1: x IS NULL  pE2: x IS NOT NULL    Result: false
+**     pE1: x IS ?2    pE2: x IS NOT NULL    Reuslt: false
+**
+** When comparing TK_COLUMN nodes between pE1 and pE2, if pE2 has
+** Expr.iTable<0 then assume a table number given by iTab.
+**
+** When in doubt, return false.  Returning true might give a performance
+** improvement.  Returning false might cause a performance reduction, but
+** it will always give the correct answer and is hence always safe.
+*/
+int sqlite3ExprImpliesExpr(Expr *pE1, Expr *pE2, int iTab){
+  if( sqlite3ExprCompare(pE1, pE2, iTab)==0 ){
+    return 1;
+  }
+  if( pE2->op==TK_OR
+   && (sqlite3ExprImpliesExpr(pE1, pE2->pLeft, iTab)
+             || sqlite3ExprImpliesExpr(pE1, pE2->pRight, iTab) )
+  ){
+    return 1;
+  }
+  if( pE2->op==TK_NOTNULL
+   && sqlite3ExprCompare(pE1->pLeft, pE2->pLeft, iTab)==0
+   && (pE1->op!=TK_ISNULL && pE1->op!=TK_IS)
+  ){
+    return 1;
   }
   return 0;
 }
@@ -4044,7 +4103,7 @@ static int analyzeAggregate(Walker *pWalker, Expr *pExpr){
         */
         struct AggInfo_func *pItem = pAggInfo->aFunc;
         for(i=0; i<pAggInfo->nFunc; i++, pItem++){
-          if( sqlite3ExprCompare(pItem->pExpr, pExpr)==0 ){
+          if( sqlite3ExprCompare(pItem->pExpr, pExpr, -1)==0 ){
             break;
           }
         }
diff --git a/lib/libsqlite3/src/fkey.c b/lib/libsqlite3/src/fkey.c
index ac35bc194cd..bb59c656f6b 100644
--- a/lib/libsqlite3/src/fkey.c
+++ b/lib/libsqlite3/src/fkey.c
@@ -422,7 +422,10 @@ static void fkLookupParent(
     }
   }
 
-  if( !pFKey->isDeferred && !pParse->pToplevel && !pParse->isMultiWrite ){
+  if( !pFKey->isDeferred && !(pParse->db->flags & SQLITE_DeferFKs)
+   && !pParse->pToplevel 
+   && !pParse->isMultiWrite 
+  ){
     /* Special case: If this is an INSERT statement that will insert exactly
     ** one row into the table, raise a constraint immediately instead of
     ** incrementing a counter. This is necessary as the VM code is being
@@ -813,7 +816,9 @@ void sqlite3FkCheck(
     SrcList *pSrc;
     int *aiCol = 0;
 
-    if( !pFKey->isDeferred && !pParse->pToplevel && !pParse->isMultiWrite ){
+    if( !pFKey->isDeferred && !(db->flags & SQLITE_DeferFKs) 
+     && !pParse->pToplevel && !pParse->isMultiWrite 
+    ){
       assert( regOld==0 && regNew!=0 );
       /* Inserting a single row into a parent table cannot cause an immediate
       ** foreign key violation. So do nothing in this case.  */
diff --git a/lib/libsqlite3/src/func.c b/lib/libsqlite3/src/func.c
index e40fdad55a8..be6e2386700 100644
--- a/lib/libsqlite3/src/func.c
+++ b/lib/libsqlite3/src/func.c
@@ -228,7 +228,7 @@ static void instrFunc(
 **
 ** If p1 is negative, then we begin abs(p1) from the end of x[].
 **
-** If p2 is negative, return the p2 characters preceeding p1.
+** If p2 is negative, return the p2 characters preceding p1.
 */
 static void substrFunc(
   sqlite3_context *context,
@@ -887,10 +887,6 @@ static const char hexdigits[] = {
 };
 
 /*
-** EXPERIMENTAL - This is not an official function.  The interface may
-** change.  This function may disappear.  Do not write code that depends
-** on this function.
-**
 ** Implementation of the QUOTE() function.  This function takes a single
 ** argument.  If the argument is numeric, the return value is the same as
 ** the argument.  If the argument is NULL, the return value is the string
@@ -1079,7 +1075,7 @@ static void zeroblobFunc(
 /*
 ** The replace() function.  Three arguments are all strings: call
 ** them A, B, and C. The result is also a string which is derived
-** from A by replacing every occurance of B with C.  The match
+** from A by replacing every occurrence of B with C.  The match
 ** must be exact.  Collating sequences are not used.
 */
 static void replaceFunc(
@@ -1526,9 +1522,9 @@ static void groupConcatFinalize(sqlite3_context *context){
   StrAccum *pAccum;
   pAccum = sqlite3_aggregate_context(context, 0);
   if( pAccum ){
-    if( pAccum->tooBig ){
+    if( pAccum->accError==STRACCUM_TOOBIG ){
       sqlite3_result_error_toobig(context);
-    }else if( pAccum->mallocFailed ){
+    }else if( pAccum->accError==STRACCUM_NOMEM ){
       sqlite3_result_error_nomem(context);
     }else{    
       sqlite3_result_text(context, sqlite3StrAccumFinish(pAccum), -1, 
diff --git a/lib/libsqlite3/src/insert.c b/lib/libsqlite3/src/insert.c
index 9a5661f59a7..1c2cabb938b 100644
--- a/lib/libsqlite3/src/insert.c
+++ b/lib/libsqlite3/src/insert.c
@@ -1379,9 +1379,19 @@ void sqlite3GenerateConstraintChecks(
   for(iCur=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, iCur++){
     int regIdx;
     int regR;
+    int addrSkipRow = 0;
 
     if( aRegIdx[iCur]==0 ) continue;  /* Skip unused indices */
 
+    if( pIdx->pPartIdxWhere ){
+      sqlite3VdbeAddOp2(v, OP_Null, 0, aRegIdx[iCur]);
+      addrSkipRow = sqlite3VdbeMakeLabel(v);
+      pParse->ckBase = regData;
+      sqlite3ExprIfFalse(pParse, pIdx->pPartIdxWhere, addrSkipRow,
+                         SQLITE_JUMPIFNULL);
+      pParse->ckBase = 0;
+    }
+
     /* Create a key for accessing the index entry */
     regIdx = sqlite3GetTempRange(pParse, pIdx->nColumn+1);
     for(i=0; i<pIdx->nColumn; i++){
@@ -1401,6 +1411,7 @@ void sqlite3GenerateConstraintChecks(
     onError = pIdx->onError;
     if( onError==OE_None ){ 
       sqlite3ReleaseTempRange(pParse, regIdx, pIdx->nColumn+1);
+      sqlite3VdbeResolveLabel(v, addrSkipRow);
       continue;  /* pIdx is not a UNIQUE index */
     }
     if( overrideError!=OE_Default ){
@@ -1470,6 +1481,7 @@ void sqlite3GenerateConstraintChecks(
       }
     }
     sqlite3VdbeJumpHere(v, j3);
+    sqlite3VdbeResolveLabel(v, addrSkipRow);
     sqlite3ReleaseTempReg(pParse, regR);
   }
   
@@ -1499,7 +1511,6 @@ void sqlite3CompleteInsertion(
 ){
   int i;
   Vdbe *v;
-  int nIdx;
   Index *pIdx;
   u8 pik_flags;
   int regData;
@@ -1508,9 +1519,11 @@ void sqlite3CompleteInsertion(
   v = sqlite3GetVdbe(pParse);
   assert( v!=0 );
   assert( pTab->pSelect==0 );  /* This table is not a VIEW */
-  for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){}
-  for(i=nIdx-1; i>=0; i--){
+  for(i=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, i++){
     if( aRegIdx[i]==0 ) continue;
+    if( pIdx->pPartIdxWhere ){
+      sqlite3VdbeAddOp2(v, OP_IsNull, aRegIdx[i], sqlite3VdbeCurrentAddr(v)+2);
+    }
     sqlite3VdbeAddOp2(v, OP_IdxInsert, baseCur+i+1, aRegIdx[i]);
     if( useSeekResult ){
       sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
@@ -1612,6 +1625,7 @@ static int xferCompatibleCollation(const char *z1, const char *z2){
 **    *   The same DESC and ASC markings occurs on all columns
 **    *   The same onError processing (OE_Abort, OE_Ignore, etc)
 **    *   The same collating sequence on each column
+**    *   The index has the exact same WHERE clause
 */
 static int xferCompatibleIndex(Index *pDest, Index *pSrc){
   int i;
@@ -1634,6 +1648,9 @@ static int xferCompatibleIndex(Index *pDest, Index *pSrc){
       return 0;   /* Different collating sequences */
     }
   }
+  if( sqlite3ExprCompare(pSrc->pPartIdxWhere, pDest->pPartIdxWhere, -1) ){
+    return 0;     /* Different WHERE clauses */
+  }
 
   /* If no test above fails then the indices must be compatible */
   return 1;
@@ -1789,7 +1806,7 @@ static int xferOptimization(
     }
   }
 #ifndef SQLITE_OMIT_CHECK
-  if( pDest->pCheck && sqlite3ExprListCompare(pSrc->pCheck, pDest->pCheck) ){
+  if( pDest->pCheck && sqlite3ExprListCompare(pSrc->pCheck,pDest->pCheck,-1) ){
     return 0;   /* Tables have different CHECK constraints.  Ticket #2252 */
   }
 #endif
diff --git a/lib/libsqlite3/src/main.c b/lib/libsqlite3/src/main.c
index 39f60421e68..7e817e59537 100644
--- a/lib/libsqlite3/src/main.c
+++ b/lib/libsqlite3/src/main.c
@@ -117,6 +117,9 @@ char *sqlite3_data_directory = 0;
 int sqlite3_initialize(void){
   MUTEX_LOGIC( sqlite3_mutex *pMaster; )       /* The main static mutex */
   int rc;                                      /* Result code */
+#ifdef SQLITE_EXTRA_INIT
+  int bRunExtraInit = 0;                       /* Extra initialization needed */
+#endif
 
 #ifdef SQLITE_OMIT_WSD
   rc = sqlite3_wsd_init(4096, 24);
@@ -214,6 +217,9 @@ int sqlite3_initialize(void){
       sqlite3PCacheBufferSetup( sqlite3GlobalConfig.pPage, 
           sqlite3GlobalConfig.szPage, sqlite3GlobalConfig.nPage);
       sqlite3GlobalConfig.isInit = 1;
+#ifdef SQLITE_EXTRA_INIT
+      bRunExtraInit = 1;
+#endif
     }
     sqlite3GlobalConfig.inProgress = 0;
   }
@@ -254,7 +260,7 @@ int sqlite3_initialize(void){
   ** compile-time option.
   */
 #ifdef SQLITE_EXTRA_INIT
-  if( rc==SQLITE_OK && sqlite3GlobalConfig.isInit ){
+  if( bRunExtraInit ){
     int SQLITE_EXTRA_INIT(const char*);
     rc = SQLITE_EXTRA_INIT(0);
   }
@@ -442,8 +448,8 @@ int sqlite3_config(int op, ...){
         memset(&sqlite3GlobalConfig.m, 0, sizeof(sqlite3GlobalConfig.m));
       }else{
         /* The heap pointer is not NULL, then install one of the
-        ** mem5.c/mem3.c methods. If neither ENABLE_MEMSYS3 nor
-        ** ENABLE_MEMSYS5 is defined, return an error.
+        ** mem5.c/mem3.c methods.  The enclosing #if guarantees at
+        ** least one of these methods is currently enabled.
         */
 #ifdef SQLITE_ENABLE_MEMSYS3
         sqlite3GlobalConfig.m = *sqlite3MemGetMemsys3();
@@ -462,7 +468,7 @@ int sqlite3_config(int op, ...){
       break;
     }
     
-    /* Record a pointer to the logger funcction and its first argument.
+    /* Record a pointer to the logger function and its first argument.
     ** The default is NULL.  Logging is disabled if the function pointer is
     ** NULL.
     */
@@ -701,7 +707,7 @@ static int binCollFunc(
 /*
 ** Another built-in collating sequence: NOCASE. 
 **
-** This collating sequence is intended to be used for "case independant
+** This collating sequence is intended to be used for "case independent
 ** comparison". SQLite's knowledge of upper and lower case equivalents
 ** extends only to the 26 characters used in the English language.
 **
@@ -1024,7 +1030,6 @@ void sqlite3RollbackAll(sqlite3 *db, int tripCode){
         inTrans = 1;
       }
       sqlite3BtreeRollback(p, tripCode);
-      db->aDb[i].inTrans = 0;
     }
   }
   sqlite3VtabRollback(db);
@@ -1038,6 +1043,8 @@ void sqlite3RollbackAll(sqlite3 *db, int tripCode){
 
   /* Any deferred constraint violations have now been resolved. */
   db->nDeferredCons = 0;
+  db->nDeferredImmCons = 0;
+  db->flags &= ~SQLITE_DeferFKs;
 
   /* If one has been configured, invoke the rollback-hook callback */
   if( db->xRollbackCallback && (inTrans || !db->autoCommit) ){
@@ -1064,6 +1071,7 @@ const char *sqlite3ErrName(int rc){
       case SQLITE_ABORT_ROLLBACK:     zName = "SQLITE_ABORT_ROLLBACK";    break;
       case SQLITE_BUSY:               zName = "SQLITE_BUSY";              break;
       case SQLITE_BUSY_RECOVERY:      zName = "SQLITE_BUSY_RECOVERY";     break;
+      case SQLITE_BUSY_SNAPSHOT:      zName = "SQLITE_BUSY_SNAPSHOT";     break;
       case SQLITE_LOCKED:             zName = "SQLITE_LOCKED";            break;
       case SQLITE_LOCKED_SHAREDCACHE: zName = "SQLITE_LOCKED_SHAREDCACHE";break;
       case SQLITE_NOMEM:              zName = "SQLITE_NOMEM";             break;
@@ -1098,6 +1106,7 @@ const char *sqlite3ErrName(int rc){
       case SQLITE_IOERR_SEEK:         zName = "SQLITE_IOERR_SEEK";        break;
       case SQLITE_IOERR_DELETE_NOENT: zName = "SQLITE_IOERR_DELETE_NOENT";break;
       case SQLITE_IOERR_MMAP:         zName = "SQLITE_IOERR_MMAP";        break;
+      case SQLITE_IOERR_GETTEMPPATH:  zName = "SQLITE_IOERR_GETTEMPPATH"; break;
       case SQLITE_CORRUPT:            zName = "SQLITE_CORRUPT";           break;
       case SQLITE_CORRUPT_VTAB:       zName = "SQLITE_CORRUPT_VTAB";      break;
       case SQLITE_NOTFOUND:           zName = "SQLITE_NOTFOUND";          break;
@@ -1137,6 +1146,7 @@ const char *sqlite3ErrName(int rc){
       case SQLITE_NOTICE_RECOVER_ROLLBACK:
                                 zName = "SQLITE_NOTICE_RECOVER_ROLLBACK"; break;
       case SQLITE_WARNING:            zName = "SQLITE_WARNING";           break;
+      case SQLITE_WARNING_AUTOINDEX:  zName = "SQLITE_WARNING_AUTOINDEX"; break;
       case SQLITE_DONE:               zName = "SQLITE_DONE";              break;
     }
   }
@@ -1297,7 +1307,7 @@ void sqlite3_progress_handler(
   sqlite3_mutex_enter(db->mutex);
   if( nOps>0 ){
     db->xProgress = xProgress;
-    db->nProgressOps = nOps;
+    db->nProgressOps = (unsigned)nOps;
     db->pProgressArg = pArg;
   }else{
     db->xProgress = 0;
@@ -1395,7 +1405,7 @@ int sqlite3CreateFunc(
   */
   p = sqlite3FindFunction(db, zFunctionName, nName, nArg, (u8)enc, 0);
   if( p && p->iPrefEnc==enc && p->nArg==nArg ){
-    if( db->activeVdbeCnt ){
+    if( db->nVdbeActive ){
       sqlite3Error(db, SQLITE_BUSY, 
         "unable to delete/modify user-function due to active statements");
       assert( !db->mallocFailed );
@@ -1976,7 +1986,7 @@ static int createCollation(
   */
   pColl = sqlite3FindCollSeq(db, (u8)enc2, zName, 0);
   if( pColl && pColl->xCmp ){
-    if( db->activeVdbeCnt ){
+    if( db->nVdbeActive ){
       sqlite3Error(db, SQLITE_BUSY, 
         "unable to delete/modify collation sequence due to active statements");
       return SQLITE_BUSY;
@@ -2174,20 +2184,20 @@ int sqlite3ParseUri(
     zFile = sqlite3_malloc(nByte);
     if( !zFile ) return SQLITE_NOMEM;
 
+    iIn = 5;
+#ifndef SQLITE_ALLOW_URI_AUTHORITY
     /* Discard the scheme and authority segments of the URI. */
     if( zUri[5]=='/' && zUri[6]=='/' ){
       iIn = 7;
       while( zUri[iIn] && zUri[iIn]!='/' ) iIn++;
-
       if( iIn!=7 && (iIn!=16 || memcmp("localhost", &zUri[7], 9)) ){
         *pzErrMsg = sqlite3_mprintf("invalid uri authority: %.*s", 
             iIn-7, &zUri[7]);
         rc = SQLITE_ERROR;
         goto parse_uri_out;
       }
-    }else{
-      iIn = 5;
     }
+#endif
 
     /* Copy the filename and any query parameters into the zFile buffer. 
     ** Decode %HH escape codes along the way. 
@@ -2451,7 +2461,10 @@ static int openDatabase(
   db->nextAutovac = -1;
   db->szMmap = sqlite3GlobalConfig.szMmap;
   db->nextPagesize = 0;
-  db->flags |= SQLITE_ShortColNames | SQLITE_AutoIndex | SQLITE_EnableTrigger
+  db->flags |= SQLITE_ShortColNames | SQLITE_EnableTrigger | SQLITE_CacheSpill
+#if !defined(SQLITE_DEFAULT_AUTOMATIC_INDEX) || SQLITE_DEFAULT_AUTOMATIC_INDEX
+                 | SQLITE_AutoIndex
+#endif
 #if SQLITE_DEFAULT_FILE_FORMAT<4
                  | SQLITE_LegacyFileFmt
 #endif
@@ -2791,8 +2804,6 @@ int sqlite3_global_recover(void){
 ** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
 ** by default.  Autocommit is disabled by a BEGIN statement and reenabled
 ** by the next COMMIT or ROLLBACK.
-**
-******* THIS IS AN EXPERIMENTAL API AND IS SUBJECT TO CHANGE ******
 */
 int sqlite3_get_autocommit(sqlite3 *db){
   return db->autoCommit;
diff --git a/lib/libsqlite3/src/mem5.c b/lib/libsqlite3/src/mem5.c
index 783cef6176c..5f99ebf43dd 100644
--- a/lib/libsqlite3/src/mem5.c
+++ b/lib/libsqlite3/src/mem5.c
@@ -130,13 +130,13 @@ static SQLITE_WSD struct Mem5Global {
 } mem5;
 
 /*
-** Access the static variable through a macro for SQLITE_OMIT_WSD
+** Access the static variable through a macro for SQLITE_OMIT_WSD.
 */
 #define mem5 GLOBAL(struct Mem5Global, mem5)
 
 /*
 ** Assuming mem5.zPool is divided up into an array of Mem5Link
-** structures, return a pointer to the idx-th such lik.
+** structures, return a pointer to the idx-th such link.
 */
 #define MEM5LINK(idx) ((Mem5Link *)(&mem5.zPool[(idx)*mem5.szAtom]))
 
@@ -232,7 +232,7 @@ static int memsys5UnlinkFirst(int iLogsize){
 ** Return a block of memory of at least nBytes in size.
 ** Return NULL if unable.  Return NULL if nBytes==0.
 **
-** The caller guarantees that nByte positive.
+** The caller guarantees that nByte is positive.
 **
 ** The caller has obtained a mutex prior to invoking this
 ** routine so there is never any chance that two or more
@@ -354,7 +354,7 @@ static void memsys5FreeUnsafe(void *pOld){
 }
 
 /*
-** Allocate nBytes of memory
+** Allocate nBytes of memory.
 */
 static void *memsys5Malloc(int nBytes){
   sqlite3_int64 *p = 0;
diff --git a/lib/libsqlite3/src/memjournal.c b/lib/libsqlite3/src/memjournal.c
index 05725948f65..65ed378b38f 100644
--- a/lib/libsqlite3/src/memjournal.c
+++ b/lib/libsqlite3/src/memjournal.c
@@ -31,12 +31,6 @@ typedef struct FileChunk FileChunk;
 */
 #define JOURNAL_CHUNKSIZE ((int)(1024-sizeof(FileChunk*)))
 
-/* Macro to find the minimum of two numeric values.
-*/
-#ifndef MIN
-# define MIN(x,y) ((x)<(y)?(x):(y))
-#endif
-
 /*
 ** The rollback journal is composed of a linked list of these structures.
 */
diff --git a/lib/libsqlite3/src/os_win.c b/lib/libsqlite3/src/os_win.c
index aeb08814b3d..10c4316448f 100644
--- a/lib/libsqlite3/src/os_win.c
+++ b/lib/libsqlite3/src/os_win.c
@@ -17,6 +17,7 @@
 
 #ifdef __CYGWIN__
 # include <sys/cygwin.h>
+# include <errno.h>
 #endif
 
 /*
@@ -85,13 +86,6 @@ WINBASEAPI BOOL WINAPI UnmapViewOfFile(LPCVOID);
 #endif /* SQLITE_WIN32_FILEMAPPING_API && !defined(SQLITE_OMIT_WAL) */
 
 /*
-** Macro to find the minimum of two numeric values.
-*/
-#ifndef MIN
-# define MIN(x,y) ((x)<(y)?(x):(y))
-#endif
-
-/*
 ** Some Microsoft compilers lack this definition.
 */
 #ifndef INVALID_FILE_ATTRIBUTES
@@ -237,6 +231,7 @@ struct winFile {
 #  define SQLITE_WIN32_HEAP_FLAGS     (0)
 #endif
 
+
 /*
 ** The winMemData structure stores information required by the Win32-specific
 ** sqlite3_mem_methods implementation.
@@ -2816,6 +2811,9 @@ static void winModeBit(winFile *pFile, unsigned char mask, int *pArg){
 
 /* Forward declaration */
 static int getTempname(int nBuf, char *zBuf);
+#if SQLITE_MAX_MMAP_SIZE>0
+static int winMapfile(winFile*, sqlite3_int64);
+#endif
 
 /*
 ** Control and query of the open file handle.
@@ -2899,13 +2897,20 @@ static int winFileControl(sqlite3_file *id, int op, void *pArg){
 #if SQLITE_MAX_MMAP_SIZE>0
     case SQLITE_FCNTL_MMAP_SIZE: {
       i64 newLimit = *(i64*)pArg;
+      int rc = SQLITE_OK;
       if( newLimit>sqlite3GlobalConfig.mxMmap ){
         newLimit = sqlite3GlobalConfig.mxMmap;
       }
       *(i64*)pArg = pFile->mmapSizeMax;
-      if( newLimit>=0 ) pFile->mmapSizeMax = newLimit;
-      OSTRACE(("FCNTL file=%p, rc=SQLITE_OK\n", pFile->h));
-      return SQLITE_OK;
+      if( newLimit>=0 && newLimit!=pFile->mmapSizeMax && pFile->nFetchOut==0 ){
+        pFile->mmapSizeMax = newLimit;
+        if( pFile->mmapSize>0 ){
+          (void)winUnmapfile(pFile);
+          rc = winMapfile(pFile, -1);
+        }
+      }
+      OSTRACE(("FCNTL file=%p, rc=%d\n", pFile->h, rc));
+      return rc;
     }
 #endif
   }
@@ -3691,10 +3696,10 @@ static int winMapfile(winFile *pFd, sqlite3_int64 nByte){
       return SQLITE_OK;
     }
     assert( (nMap % winSysInfo.dwPageSize)==0 );
+    assert( sizeof(SIZE_T)==sizeof(sqlite3_int64) || nMap<=0xffffffff );
 #if SQLITE_OS_WINRT
-    pNew = osMapViewOfFileFromApp(pFd->hMap, flags, 0, nMap);
+    pNew = osMapViewOfFileFromApp(pFd->hMap, flags, 0, (SIZE_T)nMap);
 #else
-    assert( sizeof(SIZE_T)==sizeof(sqlite3_int64) || nMap<=0xffffffff );
     pNew = osMapViewOfFile(pFd->hMap, flags, 0, 0, (SIZE_T)nMap);
 #endif
     if( pNew==NULL ){
@@ -3864,6 +3869,15 @@ static void *convertUtf8Filename(const char *zFilename){
 }
 
 /*
+** Maximum pathname length (in bytes) for windows.  The MAX_PATH macro is
+** in characters, so we allocate 3 bytes per character assuming worst-case
+** 3-bytes-per-character UTF8.
+*/
+#ifndef SQLITE_WIN32_MAX_PATH
+#  define SQLITE_WIN32_MAX_PATH   (MAX_PATH*3)
+#endif
+
+/*
 ** Create a temporary file name in zBuf.  zBuf must be big enough to
 ** hold at pVfs->mxPathname characters.
 */
@@ -3874,7 +3888,7 @@ static int getTempname(int nBuf, char *zBuf){
     "0123456789";
   size_t i, j;
   int nTempPath;
-  char zTempPath[MAX_PATH+2];
+  char zTempPath[SQLITE_WIN32_MAX_PATH+2];
 
   /* It's odd to simulate an io-error here, but really this is just
   ** using the io-error infrastructure to test that SQLite handles this
@@ -3882,19 +3896,21 @@ static int getTempname(int nBuf, char *zBuf){
   */
   SimulateIOError( return SQLITE_IOERR );
 
-  memset(zTempPath, 0, MAX_PATH+2);
-
   if( sqlite3_temp_directory ){
-    sqlite3_snprintf(MAX_PATH-30, zTempPath, "%s", sqlite3_temp_directory);
+    sqlite3_snprintf(SQLITE_WIN32_MAX_PATH-30, zTempPath, "%s",
+                     sqlite3_temp_directory);
   }
 #if !SQLITE_OS_WINRT
   else if( isNT() ){
     char *zMulti;
     WCHAR zWidePath[MAX_PATH];
-    osGetTempPathW(MAX_PATH-30, zWidePath);
+    if( osGetTempPathW(MAX_PATH-30, zWidePath)==0 ){
+      OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_GETTEMPPATH\n"));
+      return SQLITE_IOERR_GETTEMPPATH;
+    }
     zMulti = unicodeToUtf8(zWidePath);
     if( zMulti ){
-      sqlite3_snprintf(MAX_PATH-30, zTempPath, "%s", zMulti);
+      sqlite3_snprintf(SQLITE_WIN32_MAX_PATH-30, zTempPath, "%s", zMulti);
       sqlite3_free(zMulti);
     }else{
       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
@@ -3904,19 +3920,38 @@ static int getTempname(int nBuf, char *zBuf){
 #ifdef SQLITE_WIN32_HAS_ANSI
   else{
     char *zUtf8;
-    char zMbcsPath[MAX_PATH];
-    osGetTempPathA(MAX_PATH-30, zMbcsPath);
+    char zMbcsPath[SQLITE_WIN32_MAX_PATH];
+    if( osGetTempPathA(SQLITE_WIN32_MAX_PATH-30, zMbcsPath)==0 ){
+      OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_GETTEMPPATH\n"));
+      return SQLITE_IOERR_GETTEMPPATH;
+    }
     zUtf8 = sqlite3_win32_mbcs_to_utf8(zMbcsPath);
     if( zUtf8 ){
-      sqlite3_snprintf(MAX_PATH-30, zTempPath, "%s", zUtf8);
+      sqlite3_snprintf(SQLITE_WIN32_MAX_PATH-30, zTempPath, "%s", zUtf8);
       sqlite3_free(zUtf8);
     }else{
       OSTRACE(("TEMP-FILENAME rc=SQLITE_IOERR_NOMEM\n"));
       return SQLITE_IOERR_NOMEM;
     }
   }
-#endif
-#endif
+#else
+  else{
+    /*
+    ** Compiled without ANSI support and the current operating system
+    ** is not Windows NT; therefore, just zero the temporary buffer.
+    */
+    memset(zTempPath, 0, SQLITE_WIN32_MAX_PATH+2);
+  }
+#endif /* SQLITE_WIN32_HAS_ANSI */
+#else
+  else{
+    /*
+    ** Compiled for WinRT and the sqlite3_temp_directory is not set;
+    ** therefore, just zero the temporary buffer.
+    */
+    memset(zTempPath, 0, SQLITE_WIN32_MAX_PATH+2);
+  }
+#endif /* !SQLITE_OS_WINRT */
 
   /* Check that the output buffer is large enough for the temporary file 
   ** name. If it is not, return SQLITE_ERROR.
@@ -4002,7 +4037,7 @@ static int winOpen(
   /* If argument zPath is a NULL pointer, this function is required to open
   ** a temporary file. Use this buffer to store the file name in.
   */
-  char zTmpname[MAX_PATH+2];     /* Buffer used to create temp filename */
+  char zTmpname[SQLITE_WIN32_MAX_PATH+2];     /* Buffer used to create temp filename */
 
   int rc = SQLITE_OK;            /* Function Return Code */
 #if !defined(NDEBUG) || SQLITE_OS_WINCE
@@ -4068,8 +4103,7 @@ static int winOpen(
   */
   if( !zUtf8Name ){
     assert(isDelete && !isOpenJournal);
-    memset(zTmpname, 0, MAX_PATH+2);
-    rc = getTempname(MAX_PATH+2, zTmpname);
+    rc = getTempname(SQLITE_WIN32_MAX_PATH+2, zTmpname);
     if( rc!=SQLITE_OK ){
       OSTRACE(("OPEN name=%s, rc=%s", zUtf8Name, sqlite3ErrName(rc)));
       return rc;
@@ -4500,7 +4534,7 @@ static int winFullPathname(
 #if defined(__CYGWIN__)
   SimulateIOError( return SQLITE_ERROR );
   UNUSED_PARAMETER(nFull);
-  assert( pVfs->mxPathname>=MAX_PATH );
+  assert( pVfs->mxPathname>=SQLITE_WIN32_MAX_PATH );
   assert( nFull>=pVfs->mxPathname );
   if ( sqlite3_data_directory && !winIsVerbatimPathname(zRelative) ){
     /*
@@ -4509,14 +4543,21 @@ static int winFullPathname(
     **       for converting the relative path name to an absolute
     **       one by prepending the data directory and a slash.
     */
-    char zOut[MAX_PATH+1];
-    memset(zOut, 0, MAX_PATH+1);
-    cygwin_conv_path(CCP_POSIX_TO_WIN_A|CCP_RELATIVE, zRelative, zOut,
-                     MAX_PATH+1);
+    char zOut[SQLITE_WIN32_MAX_PATH+1];
+    if( cygwin_conv_path(CCP_POSIX_TO_WIN_A|CCP_RELATIVE, zRelative, zOut,
+                         SQLITE_WIN32_MAX_PATH+1)<0 ){
+      winLogError(SQLITE_CANTOPEN_FULLPATH, (DWORD)errno, "cygwin_conv_path",
+                  zRelative);
+      return SQLITE_CANTOPEN_FULLPATH;
+    }
     sqlite3_snprintf(MIN(nFull, pVfs->mxPathname), zFull, "%s\\%s",
                      sqlite3_data_directory, zOut);
   }else{
-    cygwin_conv_path(CCP_POSIX_TO_WIN_A, zRelative, zFull, nFull);
+    if( cygwin_conv_path(CCP_POSIX_TO_WIN_A, zRelative, zFull, nFull)<0 ){
+      winLogError(SQLITE_CANTOPEN_FULLPATH, (DWORD)errno, "cygwin_conv_path",
+                  zRelative);
+      return SQLITE_CANTOPEN_FULLPATH;
+    }
   }
   return SQLITE_OK;
 #endif
@@ -4858,7 +4899,7 @@ int sqlite3_os_init(void){
   static sqlite3_vfs winVfs = {
     3,                   /* iVersion */
     sizeof(winFile),     /* szOsFile */
-    MAX_PATH,            /* mxPathname */
+    SQLITE_WIN32_MAX_PATH, /* mxPathname */
     0,                   /* pNext */
     "win32",             /* zName */
     0,                   /* pAppData */
diff --git a/lib/libsqlite3/src/pager.c b/lib/libsqlite3/src/pager.c
index 1c6a84fea4b..d675b85821e 100644
--- a/lib/libsqlite3/src/pager.c
+++ b/lib/libsqlite3/src/pager.c
@@ -454,6 +454,13 @@ struct PagerSavepoint {
 };
 
 /*
+** Bits of the Pager.doNotSpill flag.  See further description below.
+*/
+#define SPILLFLAG_OFF         0x01      /* Never spill cache.  Set via pragma */
+#define SPILLFLAG_ROLLBACK    0x02      /* Current rolling back, so do not spill */
+#define SPILLFLAG_NOSYNC      0x04      /* Spill is ok, but do not sync */
+
+/*
 ** A open page cache is an instance of struct Pager. A description of
 ** some of the more important member variables follows:
 **
@@ -519,19 +526,21 @@ struct PagerSavepoint {
 **   journal file from being successfully finalized, the setMaster flag
 **   is cleared anyway (and the pager will move to ERROR state).
 **
-** doNotSpill, doNotSyncSpill
+** doNotSpill
 **
-**   These two boolean variables control the behavior of cache-spills
-**   (calls made by the pcache module to the pagerStress() routine to
-**   write cached data to the file-system in order to free up memory).
+**   This variables control the behavior of cache-spills  (calls made by
+**   the pcache module to the pagerStress() routine to write cached data
+**   to the file-system in order to free up memory).
 **
-**   When doNotSpill is non-zero, writing to the database from pagerStress()
-**   is disabled altogether. This is done in a very obscure case that
+**   When bits SPILLFLAG_OFF or SPILLFLAG_ROLLBACK of doNotSpill are set,
+**   writing to the database from pagerStress() is disabled altogether.
+**   The SPILLFLAG_ROLLBACK case is done in a very obscure case that
 **   comes up during savepoint rollback that requires the pcache module
 **   to allocate a new page to prevent the journal file from being written
-**   while it is being traversed by code in pager_playback().
+**   while it is being traversed by code in pager_playback().  The SPILLFLAG_OFF
+**   case is a user preference.
 ** 
-**   If doNotSyncSpill is non-zero, writing to the database from pagerStress()
+**   If the SPILLFLAG_NOSYNC bit is set, writing to the database from pagerStress()
 **   is permitted, but syncing the journal file is not. This flag is set
 **   by sqlite3PagerWrite() when the file-system sector-size is larger than
 **   the database page-size in order to prevent a journal sync from happening 
@@ -635,7 +644,6 @@ struct Pager {
   u8 changeCountDone;         /* Set after incrementing the change-counter */
   u8 setMaster;               /* True if a m-j name has been written to jrnl */
   u8 doNotSpill;              /* Do not spill the cache when non-zero */
-  u8 doNotSyncSpill;          /* Do not do a spill that requires jrnl sync */
   u8 subjInMemory;            /* True to use in-memory sub-journals */
   Pgno dbSize;                /* Number of pages in the database */
   Pgno dbOrigSize;            /* dbSize before the current transaction */
@@ -1014,13 +1022,17 @@ static char *print_pager_state(Pager *p){
 **     PagerSavepoint.pInSavepoint.
 */
 static int subjRequiresPage(PgHdr *pPg){
-  Pgno pgno = pPg->pgno;
   Pager *pPager = pPg->pPager;
+  PagerSavepoint *p;
+  Pgno pgno;
   int i;
-  for(i=0; i<pPager->nSavepoint; i++){
-    PagerSavepoint *p = &pPager->aSavepoint[i];
-    if( p->nOrig>=pgno && 0==sqlite3BitvecTest(p->pInSavepoint, pgno) ){
-      return 1;
+  if( pPager->nSavepoint ){
+    pgno = pPg->pgno;
+    for(i=0; i<pPager->nSavepoint; i++){
+      p = &pPager->aSavepoint[i];
+      if( p->nOrig>=pgno && 0==sqlite3BitvecTest(p->pInSavepoint, pgno) ){
+        return 1;
+      }
     }
   }
   return 0;
@@ -1812,6 +1824,7 @@ static void pager_unlock(Pager *pPager){
     pPager->changeCountDone = pPager->tempFile;
     pPager->eState = PAGER_OPEN;
     pPager->errCode = SQLITE_OK;
+    if( USEFETCH(pPager) ) sqlite3OsUnfetch(pPager->fd, 0, 0);
   }
 
   pPager->journalOff = 0;
@@ -2294,11 +2307,11 @@ static int pager_playback_one_page(
     ** requiring a journal-sync before it is written.
     */
     assert( isSavepnt );
-    assert( pPager->doNotSpill==0 );
-    pPager->doNotSpill++;
+    assert( (pPager->doNotSpill & SPILLFLAG_ROLLBACK)==0 );
+    pPager->doNotSpill |= SPILLFLAG_ROLLBACK;
     rc = sqlite3PagerAcquire(pPager, pgno, &pPg, 1);
-    assert( pPager->doNotSpill==1 );
-    pPager->doNotSpill--;
+    assert( (pPager->doNotSpill & SPILLFLAG_ROLLBACK)!=0 );
+    pPager->doNotSpill &= ~SPILLFLAG_ROLLBACK;
     if( rc!=SQLITE_OK ) return rc;
     pPg->flags &= ~PGHDR_NEED_READ;
     sqlite3PcacheMakeDirty(pPg);
@@ -2865,12 +2878,6 @@ static int readDbPage(PgHdr *pPg, u32 iFrame){
   assert( pPager->eState>=PAGER_READER && !MEMDB );
   assert( isOpen(pPager->fd) );
 
-  if( NEVER(!isOpen(pPager->fd)) ){
-    assert( pPager->tempFile );
-    memset(pPg->pData, 0, pPager->pageSize);
-    return SQLITE_OK;
-  }
-
 #ifndef SQLITE_OMIT_WAL
   if( iFrame ){
     /* Try to pull the page from the write-ahead log. */
@@ -3378,10 +3385,10 @@ void sqlite3PagerSetCachesize(Pager *pPager, int mxPage){
 static void pagerFixMaplimit(Pager *pPager){
 #if SQLITE_MAX_MMAP_SIZE>0
   sqlite3_file *fd = pPager->fd;
-  if( isOpen(fd) ){
+  if( isOpen(fd) && fd->pMethods->iVersion>=3 ){
     sqlite3_int64 sz;
-    pPager->bUseFetch = (fd->pMethods->iVersion>=3) && pPager->szMmap>0;
     sz = pPager->szMmap;
+    pPager->bUseFetch = (sz>0);
     sqlite3OsFileControlHint(pPager->fd, SQLITE_FCNTL_MMAP_SIZE, &sz);
   }
 #endif
@@ -3403,9 +3410,12 @@ void sqlite3PagerShrink(Pager *pPager){
 }
 
 /*
-** Adjust the robustness of the database to damage due to OS crashes
-** or power failures by changing the number of syncs()s when writing
-** the rollback journal.  There are three levels:
+** Adjust settings of the pager to those specified in the pgFlags parameter.
+**
+** The "level" in pgFlags & PAGER_SYNCHRONOUS_MASK sets the robustness
+** of the database to damage due to OS crashes or power failures by
+** changing the number of syncs()s when writing the journals.
+** There are three levels:
 **
 **    OFF       sqlite3OsSync() is never called.  This is the default
 **              for temporary and transient files.
@@ -3446,22 +3456,21 @@ void sqlite3PagerShrink(Pager *pPager){
 ** and FULL=3.
 */
 #ifndef SQLITE_OMIT_PAGER_PRAGMAS
-void sqlite3PagerSetSafetyLevel(
+void sqlite3PagerSetFlags(
   Pager *pPager,        /* The pager to set safety level for */
-  int level,            /* PRAGMA synchronous.  1=OFF, 2=NORMAL, 3=FULL */  
-  int bFullFsync,       /* PRAGMA fullfsync */
-  int bCkptFullFsync    /* PRAGMA checkpoint_fullfsync */
+  unsigned pgFlags      /* Various flags */
 ){
+  unsigned level = pgFlags & PAGER_SYNCHRONOUS_MASK;
   assert( level>=1 && level<=3 );
   pPager->noSync =  (level==1 || pPager->tempFile) ?1:0;
   pPager->fullSync = (level==3 && !pPager->tempFile) ?1:0;
   if( pPager->noSync ){
     pPager->syncFlags = 0;
     pPager->ckptSyncFlags = 0;
-  }else if( bFullFsync ){
+  }else if( pgFlags & PAGER_FULLFSYNC ){
     pPager->syncFlags = SQLITE_SYNC_FULL;
     pPager->ckptSyncFlags = SQLITE_SYNC_FULL;
-  }else if( bCkptFullFsync ){
+  }else if( pgFlags & PAGER_CKPT_FULLFSYNC ){
     pPager->syncFlags = SQLITE_SYNC_NORMAL;
     pPager->ckptSyncFlags = SQLITE_SYNC_FULL;
   }else{
@@ -3472,6 +3481,11 @@ void sqlite3PagerSetSafetyLevel(
   if( pPager->fullSync ){
     pPager->walSyncFlags |= WAL_SYNC_TRANSACTIONS;
   }
+  if( pgFlags & PAGER_CACHESPILL ){
+    pPager->doNotSpill &= ~SPILLFLAG_OFF;
+  }else{
+    pPager->doNotSpill |= SPILLFLAG_OFF;
+  }
 }
 #endif
 
@@ -4214,7 +4228,8 @@ static int pager_write_pagelist(Pager *pPager, PgHdr *pList){
   */
   assert( rc!=SQLITE_OK || isOpen(pPager->fd) );
   if( rc==SQLITE_OK 
-   && (pList->pDirty ? pPager->dbSize : pList->pgno+1)>pPager->dbHintSize 
+   && pPager->dbHintSize<pPager->dbSize
+   && (pList->pDirty || pList->pgno>pPager->dbHintSize)
   ){
     sqlite3_int64 szFile = pPager->pageSize * (sqlite3_int64)pPager->dbSize;
     sqlite3OsFileControlHint(pPager->fd, SQLITE_FCNTL_SIZE_HINT, &szFile);
@@ -4371,13 +4386,14 @@ static int pagerStress(void *p, PgHdr *pPg){
   assert( pPg->pPager==pPager );
   assert( pPg->flags&PGHDR_DIRTY );
 
-  /* The doNotSyncSpill flag is set during times when doing a sync of
+  /* The doNotSpill NOSYNC bit is set during times when doing a sync of
   ** journal (and adding a new header) is not allowed.  This occurs
   ** during calls to sqlite3PagerWrite() while trying to journal multiple
   ** pages belonging to the same sector.
   **
-  ** The doNotSpill flag inhibits all cache spilling regardless of whether
-  ** or not a sync is required.  This is set during a rollback.
+  ** The doNotSpill ROLLBACK and OFF bits inhibits all cache spilling
+  ** regardless of whether or not a sync is required.  This is set during
+  ** a rollback or by user request, respectively.
   **
   ** Spilling is also prohibited when in an error state since that could
   ** lead to database corruption.   In the current implementaton it 
@@ -4387,8 +4403,13 @@ static int pagerStress(void *p, PgHdr *pPg){
   ** test for the error state as a safeguard against future changes.
   */
   if( NEVER(pPager->errCode) ) return SQLITE_OK;
-  if( pPager->doNotSpill ) return SQLITE_OK;
-  if( pPager->doNotSyncSpill && (pPg->flags & PGHDR_NEED_SYNC)!=0 ){
+  testcase( pPager->doNotSpill & SPILLFLAG_ROLLBACK );
+  testcase( pPager->doNotSpill & SPILLFLAG_OFF );
+  testcase( pPager->doNotSpill & SPILLFLAG_NOSYNC );
+  if( pPager->doNotSpill
+   && ((pPager->doNotSpill & (SPILLFLAG_ROLLBACK|SPILLFLAG_OFF))!=0
+      || (pPg->flags & PGHDR_NEED_SYNC)!=0)
+  ){
     return SQLITE_OK;
   }
 
@@ -5179,7 +5200,7 @@ static void pagerUnlockIfUnused(Pager *pPager){
 ** page is initialized to all zeros. 
 **
 ** If noContent is true, it means that we do not care about the contents
-** of the page. This occurs in two seperate scenarios:
+** of the page. This occurs in two scenarios:
 **
 **   a) When reading a free-list leaf page from the database, and
 **
@@ -5210,19 +5231,19 @@ int sqlite3PagerAcquire(
   Pager *pPager,      /* The pager open on the database file */
   Pgno pgno,          /* Page number to fetch */
   DbPage **ppPage,    /* Write a pointer to the page here */
-  int flags           /* PAGER_ACQUIRE_XXX flags */
+  int flags           /* PAGER_GET_XXX flags */
 ){
   int rc = SQLITE_OK;
   PgHdr *pPg = 0;
   u32 iFrame = 0;                 /* Frame to read from WAL file */
-  const int noContent = (flags & PAGER_ACQUIRE_NOCONTENT);
+  const int noContent = (flags & PAGER_GET_NOCONTENT);
 
   /* It is acceptable to use a read-only (mmap) page for any page except
   ** page 1 if there is no write-transaction open or the ACQUIRE_READONLY
   ** flag was specified by the caller. And so long as the db is not a 
   ** temporary or in-memory database.  */
   const int bMmapOk = (pgno!=1 && USEFETCH(pPager)
-   && (pPager->eState==PAGER_READER || (flags & PAGER_ACQUIRE_READONLY))
+   && (pPager->eState==PAGER_READER || (flags & PAGER_GET_READONLY))
 #ifdef SQLITE_HAS_CODEC
    && pPager->xCodec==0
 #endif
@@ -5742,13 +5763,13 @@ int sqlite3PagerWrite(DbPage *pDbPage){
     int ii;                   /* Loop counter */
     int needSync = 0;         /* True if any page has PGHDR_NEED_SYNC */
 
-    /* Set the doNotSyncSpill flag to 1. This is because we cannot allow
+    /* Set the doNotSpill NOSYNC bit to 1. This is because we cannot allow
     ** a journal header to be written between the pages journaled by
     ** this function.
     */
     assert( !MEMDB );
-    assert( pPager->doNotSyncSpill==0 );
-    pPager->doNotSyncSpill++;
+    assert( (pPager->doNotSpill & SPILLFLAG_NOSYNC)==0 );
+    pPager->doNotSpill |= SPILLFLAG_NOSYNC;
 
     /* This trick assumes that both the page-size and sector-size are
     ** an integer power of 2. It sets variable pg1 to the identifier
@@ -5807,8 +5828,8 @@ int sqlite3PagerWrite(DbPage *pDbPage){
       }
     }
 
-    assert( pPager->doNotSyncSpill==1 );
-    pPager->doNotSyncSpill--;
+    assert( (pPager->doNotSpill & SPILLFLAG_NOSYNC)!=0 );
+    pPager->doNotSpill &= ~SPILLFLAG_NOSYNC;
   }else{
     rc = pager_write(pDbPage);
   }
@@ -6589,7 +6610,27 @@ void sqlite3PagerSetCodec(
 void *sqlite3PagerGetCodec(Pager *pPager){
   return pPager->pCodec;
 }
-#endif
+
+/*
+** This function is called by the wal module when writing page content
+** into the log file.
+**
+** This function returns a pointer to a buffer containing the encrypted
+** page content. If a malloc fails, this function may return NULL.
+*/
+void *sqlite3PagerCodec(PgHdr *pPg){
+  void *aData = 0;
+  CODEC2(pPg->pPager, pPg->pData, pPg->pgno, 6, return 0, aData);
+  return aData;
+}
+
+/*
+** Return the current pager state
+*/
+int sqlite3PagerState(Pager *pPager){
+  return pPager->eState;
+}
+#endif /* SQLITE_HAS_CODEC */
 
 #ifndef SQLITE_OMIT_AUTOVACUUM
 /*
@@ -7144,19 +7185,4 @@ int sqlite3PagerWalFramesize(Pager *pPager){
 }
 #endif
 
-#ifdef SQLITE_HAS_CODEC
-/*
-** This function is called by the wal module when writing page content
-** into the log file.
-**
-** This function returns a pointer to a buffer containing the encrypted
-** page content. If a malloc fails, this function may return NULL.
-*/
-void *sqlite3PagerCodec(PgHdr *pPg){
-  void *aData = 0;
-  CODEC2(pPg->pPager, pPg->pData, pPg->pgno, 6, return 0, aData);
-  return aData;
-}
-#endif /* SQLITE_HAS_CODEC */
-
 #endif /* SQLITE_OMIT_DISKIO */
diff --git a/lib/libsqlite3/src/pager.h b/lib/libsqlite3/src/pager.h
index 6f659136e27..7851d283454 100644
--- a/lib/libsqlite3/src/pager.h
+++ b/lib/libsqlite3/src/pager.h
@@ -81,8 +81,20 @@ typedef struct PgHdr DbPage;
 /*
 ** Flags that make up the mask passed to sqlite3PagerAcquire().
 */
-#define PAGER_ACQUIRE_NOCONTENT     0x01  /* Do not load data from disk */
-#define PAGER_ACQUIRE_READONLY      0x02  /* Read-only page is acceptable */
+#define PAGER_GET_NOCONTENT     0x01  /* Do not load data from disk */
+#define PAGER_GET_READONLY      0x02  /* Read-only page is acceptable */
+
+/*
+** Flags for sqlite3PagerSetFlags()
+*/
+#define PAGER_SYNCHRONOUS_OFF       0x01  /* PRAGMA synchronous=OFF */
+#define PAGER_SYNCHRONOUS_NORMAL    0x02  /* PRAGMA synchronous=NORMAL */
+#define PAGER_SYNCHRONOUS_FULL      0x03  /* PRAGMA synchronous=FULL */
+#define PAGER_SYNCHRONOUS_MASK      0x03  /* Mask for three values above */
+#define PAGER_FULLFSYNC             0x04  /* PRAGMA fullfsync=ON */
+#define PAGER_CKPT_FULLFSYNC        0x08  /* PRAGMA checkpoint_fullfsync=ON */
+#define PAGER_CACHESPILL            0x10  /* PRAGMA cache_spill=ON */
+#define PAGER_FLAGS_MASK            0x1c  /* All above except SYNCHRONOUS */
 
 /*
 ** The remainder of this file contains the declarations of the functions
@@ -110,7 +122,7 @@ int sqlite3PagerMaxPageCount(Pager*, int);
 void sqlite3PagerSetCachesize(Pager*, int);
 void sqlite3PagerSetMmapLimit(Pager *, sqlite3_int64);
 void sqlite3PagerShrink(Pager*);
-void sqlite3PagerSetSafetyLevel(Pager*,int,int,int);
+void sqlite3PagerSetFlags(Pager*,unsigned);
 int sqlite3PagerLockingMode(Pager *, int);
 int sqlite3PagerSetJournalMode(Pager *, int);
 int sqlite3PagerGetJournalMode(Pager*);
diff --git a/lib/libsqlite3/src/pcache1.c b/lib/libsqlite3/src/pcache1.c
index 4147d2eff55..df9d8775370 100644
--- a/lib/libsqlite3/src/pcache1.c
+++ b/lib/libsqlite3/src/pcache1.c
@@ -562,7 +562,7 @@ static sqlite3_pcache *pcache1Create(int szPage, int szExtra, int bPurgeable){
   int sz;               /* Bytes of memory required to allocate the new cache */
 
   /*
-  ** The seperateCache variable is true if each PCache has its own private
+  ** The separateCache variable is true if each PCache has its own private
   ** PGroup.  In other words, separateCache is true for mode (1) where no
   ** mutexing is required.
   **
@@ -765,6 +765,7 @@ static sqlite3_pcache_page *pcache1Fetch(
   if( pCache->nPage>=pCache->nHash && pcache1ResizeHash(pCache) ){
     goto fetch_out;
   }
+  assert( pCache->nHash>0 && pCache->apHash );
 
   /* Step 4. Try to recycle a page. */
   if( pCache->bPurgeable && pGroup->pLruTail && (
diff --git a/lib/libsqlite3/src/pragma.c b/lib/libsqlite3/src/pragma.c
index 3056a7d8e2b..ffaf69e9e44 100644
--- a/lib/libsqlite3/src/pragma.c
+++ b/lib/libsqlite3/src/pragma.c
@@ -158,6 +158,36 @@ static void returnSingleInt(Parse *pParse, const char *zLabel, i64 value){
   sqlite3VdbeAddOp2(v, OP_ResultRow, mem, 1);
 }
 
+
+/*
+** Set the safety_level and pager flags for pager iDb.  Or if iDb<0
+** set these values for all pagers.
+*/
+#ifndef SQLITE_OMIT_PAGER_PRAGMAS
+static void setAllPagerFlags(sqlite3 *db){
+  if( db->autoCommit ){
+    Db *pDb = db->aDb;
+    int n = db->nDb;
+    assert( SQLITE_FullFSync==PAGER_FULLFSYNC );
+    assert( SQLITE_CkptFullFSync==PAGER_CKPT_FULLFSYNC );
+    assert( SQLITE_CacheSpill==PAGER_CACHESPILL );
+    assert( (PAGER_FULLFSYNC | PAGER_CKPT_FULLFSYNC | PAGER_CACHESPILL)
+             ==  PAGER_FLAGS_MASK );
+    assert( (pDb->safety_level & PAGER_SYNCHRONOUS_MASK)==pDb->safety_level );
+    while( (n--) > 0 ){
+      if( pDb->pBt ){
+        sqlite3BtreeSetPagerFlags(pDb->pBt,
+                 pDb->safety_level | (db->flags & PAGER_FLAGS_MASK) );
+      }
+      pDb++;
+    }
+  }
+}
+#else
+# define setAllPagerFlags(X)  /* no-op */
+#endif
+
+
 #ifndef SQLITE_OMIT_FLAG_PRAGMAS
 /*
 ** Check to see if zRight and zLeft refer to a pragma that queries
@@ -176,7 +206,9 @@ static int flagPragma(Parse *pParse, const char *zLeft, const char *zRight){
     { "legacy_file_format",       SQLITE_LegacyFileFmt },
     { "fullfsync",                SQLITE_FullFSync     },
     { "checkpoint_fullfsync",     SQLITE_CkptFullFSync },
+    { "cache_spill",              SQLITE_CacheSpill    },
     { "reverse_unordered_selects", SQLITE_ReverseOrder  },
+    { "query_only",               SQLITE_QueryOnly     },
 #ifndef SQLITE_OMIT_AUTOMATIC_INDEX
     { "automatic_index",          SQLITE_AutoIndex     },
 #endif
@@ -197,12 +229,13 @@ static int flagPragma(Parse *pParse, const char *zLeft, const char *zRight){
     /* TODO: Maybe it shouldn't be possible to change the ReadUncommitted
     ** flag if there are any active statements. */
     { "read_uncommitted",         SQLITE_ReadUncommitted },
-    { "recursive_triggers",       SQLITE_RecTriggers },
+    { "recursive_triggers",       SQLITE_RecTriggers   },
 
     /* This flag may only be set if both foreign-key and trigger support
     ** are present in the build.  */
 #if !defined(SQLITE_OMIT_FOREIGN_KEY) && !defined(SQLITE_OMIT_TRIGGER)
-    { "foreign_keys",             SQLITE_ForeignKeys },
+    { "foreign_keys",             SQLITE_ForeignKeys   },
+    { "defer_foreign_keys",       SQLITE_DeferFKs      },
 #endif
   };
   int i;
@@ -228,6 +261,7 @@ static int flagPragma(Parse *pParse, const char *zLeft, const char *zRight){
             db->flags |= mask;
           }else{
             db->flags &= ~mask;
+            if( mask==SQLITE_DeferFKs ) db->nDeferredImmCons = 0;
           }
 
           /* Many of the flag-pragmas modify the code generated by the SQL 
@@ -774,11 +808,15 @@ void sqlite3Pragma(
       }
     }
     sz = -1;
-    if( sqlite3_file_control(db,zDb,SQLITE_FCNTL_MMAP_SIZE,&sz)==SQLITE_OK ){
+    rc = sqlite3_file_control(db, zDb, SQLITE_FCNTL_MMAP_SIZE, &sz);
 #if SQLITE_MAX_MMAP_SIZE==0
-      sz = 0;
+    sz = 0;
 #endif
+    if( rc==SQLITE_OK ){
       returnSingleInt(pParse, "mmap_size", sz);
+    }else if( rc!=SQLITE_NOTFOUND ){
+      pParse->nErr++;
+      pParse->rc = rc;
     }
   }else
 
@@ -959,6 +997,7 @@ void sqlite3Pragma(
             "Safety level may not be changed inside a transaction");
       }else{
         pDb->safety_level = getSafetyLevel(zRight,0,1)+1;
+        setAllPagerFlags(db);
       }
     }
   }else
@@ -966,8 +1005,7 @@ void sqlite3Pragma(
 
 #ifndef SQLITE_OMIT_FLAG_PRAGMAS
   if( flagPragma(pParse, zLeft, zRight) ){
-    /* The flagPragma() subroutine also generates any necessary code
-    ** there is nothing more to do here */
+    setAllPagerFlags(db);
   }else
 #endif /* SQLITE_OMIT_FLAG_PRAGMAS */
 
@@ -1309,7 +1347,7 @@ void sqlite3Pragma(
 #endif
 
 #ifndef SQLITE_OMIT_INTEGRITY_CHECK
-  /* Pragma "quick_check" is an experimental reduced version of 
+  /* Pragma "quick_check" is reduced version of 
   ** integrity_check designed to detect most database corruption
   ** without most of the overhead of a full integrity-check.
   */
@@ -1393,9 +1431,7 @@ void sqlite3Pragma(
       }
 
       /* Make sure sufficient number of registers have been allocated */
-      if( pParse->nMem < cnt+4 ){
-        pParse->nMem = cnt+4;
-      }
+      pParse->nMem = MAX( pParse->nMem, cnt+7 );
 
       /* Do the b-tree integrity checks */
       sqlite3VdbeAddOp3(v, OP_IntegrityCk, 2, cnt, 1);
@@ -1420,12 +1456,15 @@ void sqlite3Pragma(
         addr = sqlite3VdbeAddOp1(v, OP_IfPos, 1);  /* Stop if out of errors */
         sqlite3VdbeAddOp2(v, OP_Halt, 0, 0);
         sqlite3VdbeJumpHere(v, addr);
+        sqlite3ExprCacheClear(pParse);
         sqlite3OpenTableAndIndices(pParse, pTab, 1, OP_OpenRead);
-        sqlite3VdbeAddOp2(v, OP_Integer, 0, 2);  /* reg(2) will count entries */
-        loopTop = sqlite3VdbeAddOp2(v, OP_Rewind, 1, 0);
-        sqlite3VdbeAddOp2(v, OP_AddImm, 2, 1);   /* increment entry count */
         for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
-          int jmp2;
+          sqlite3VdbeAddOp2(v, OP_Integer, 0, 7+j); /* index entries counter */
+        }
+        pParse->nMem = MAX(pParse->nMem, 7+j);
+        loopTop = sqlite3VdbeAddOp2(v, OP_Rewind, 1, 0) + 1;
+        for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
+          int jmp2, jmp3;
           int r1;
           static const VdbeOpList idxErr[] = {
             { OP_AddImm,      1, -1,  0},
@@ -1440,7 +1479,8 @@ void sqlite3Pragma(
             { OP_IfPos,       1,  0,  0},    /* 9 */
             { OP_Halt,        0,  0,  0},
           };
-          r1 = sqlite3GenerateIndexKey(pParse, pIdx, 1, 3, 0);
+          r1 = sqlite3GenerateIndexKey(pParse, pIdx, 1, 3, 0, &jmp3);
+          sqlite3VdbeAddOp2(v, OP_AddImm, 7+j, 1);  /* increment entry count */
           jmp2 = sqlite3VdbeAddOp4Int(v, OP_Found, j+2, 0, r1, pIdx->nColumn+1);
           addr = sqlite3VdbeAddOpList(v, ArraySize(idxErr), idxErr);
           sqlite3VdbeChangeP4(v, addr+1, "rowid ", P4_STATIC);
@@ -1448,35 +1488,25 @@ void sqlite3Pragma(
           sqlite3VdbeChangeP4(v, addr+4, pIdx->zName, P4_TRANSIENT);
           sqlite3VdbeJumpHere(v, addr+9);
           sqlite3VdbeJumpHere(v, jmp2);
+          sqlite3VdbeResolveLabel(v, jmp3);
         }
-        sqlite3VdbeAddOp2(v, OP_Next, 1, loopTop+1);
-        sqlite3VdbeJumpHere(v, loopTop);
+        sqlite3VdbeAddOp2(v, OP_Next, 1, loopTop);
+        sqlite3VdbeJumpHere(v, loopTop-1);
+#ifndef SQLITE_OMIT_BTREECOUNT
+        sqlite3VdbeAddOp4(v, OP_String8, 0, 2, 0, 
+                     "wrong # of entries in index ", P4_STATIC);
         for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
-          static const VdbeOpList cntIdx[] = {
-             { OP_Integer,      0,  3,  0},
-             { OP_Rewind,       0,  0,  0},  /* 1 */
-             { OP_AddImm,       3,  1,  0},
-             { OP_Next,         0,  0,  0},  /* 3 */
-             { OP_Eq,           2,  0,  3},  /* 4 */
-             { OP_AddImm,       1, -1,  0},
-             { OP_String8,      0,  2,  0},  /* 6 */
-             { OP_String8,      0,  3,  0},  /* 7 */
-             { OP_Concat,       3,  2,  2},
-             { OP_ResultRow,    2,  1,  0},
-          };
-          addr = sqlite3VdbeAddOp1(v, OP_IfPos, 1);
+          addr = sqlite3VdbeCurrentAddr(v);
+          sqlite3VdbeAddOp2(v, OP_IfPos, 1, addr+2);
           sqlite3VdbeAddOp2(v, OP_Halt, 0, 0);
-          sqlite3VdbeJumpHere(v, addr);
-          addr = sqlite3VdbeAddOpList(v, ArraySize(cntIdx), cntIdx);
-          sqlite3VdbeChangeP1(v, addr+1, j+2);
-          sqlite3VdbeChangeP2(v, addr+1, addr+4);
-          sqlite3VdbeChangeP1(v, addr+3, j+2);
-          sqlite3VdbeChangeP2(v, addr+3, addr+2);
-          sqlite3VdbeJumpHere(v, addr+4);
-          sqlite3VdbeChangeP4(v, addr+6, 
-                     "wrong # of entries in index ", P4_STATIC);
-          sqlite3VdbeChangeP4(v, addr+7, pIdx->zName, P4_TRANSIENT);
+          sqlite3VdbeAddOp2(v, OP_Count, j+2, 3);
+          sqlite3VdbeAddOp3(v, OP_Eq, 7+j, addr+8, 3);
+          sqlite3VdbeAddOp2(v, OP_AddImm, 1, -1);
+          sqlite3VdbeAddOp4(v, OP_String8, 0, 3, 0, pIdx->zName, P4_TRANSIENT);
+          sqlite3VdbeAddOp3(v, OP_Concat, 3, 2, 7);
+          sqlite3VdbeAddOp2(v, OP_ResultRow, 7, 1);
         }
+#endif /* SQLITE_OMIT_BTREECOUNT */
       } 
     }
     addr = sqlite3VdbeAddOpList(v, ArraySize(endCode), endCode);
@@ -1767,10 +1797,10 @@ void sqlite3Pragma(
 
 #ifdef SQLITE_HAS_CODEC
   if( sqlite3StrICmp(zLeft, "key")==0 && zRight ){
-    sqlite3_key(db, zRight, sqlite3Strlen30(zRight));
+    sqlite3_key_v2(db, zDb, zRight, sqlite3Strlen30(zRight));
   }else
   if( sqlite3StrICmp(zLeft, "rekey")==0 && zRight ){
-    sqlite3_rekey(db, zRight, sqlite3Strlen30(zRight));
+    sqlite3_rekey_v2(db, zDb, zRight, sqlite3Strlen30(zRight));
   }else
   if( zRight && (sqlite3StrICmp(zLeft, "hexkey")==0 ||
                  sqlite3StrICmp(zLeft, "hexrekey")==0) ){
@@ -1782,9 +1812,9 @@ void sqlite3Pragma(
       zKey[i/2] = (h2 & 0x0f) | ((h1 & 0xf)<<4);
     }
     if( (zLeft[3] & 0xf)==0xb ){
-      sqlite3_key(db, zKey, i/2);
+      sqlite3_key_v2(db, zDb, zKey, i/2);
     }else{
-      sqlite3_rekey(db, zKey, i/2);
+      sqlite3_rekey_v2(db, zDb, zKey, i/2);
     }
   }else
 #endif
@@ -1806,17 +1836,6 @@ void sqlite3Pragma(
  
   {/* Empty ELSE clause */}
 
-  /*
-  ** Reset the safety level, in case the fullfsync flag or synchronous
-  ** setting changed.
-  */
-#ifndef SQLITE_OMIT_PAGER_PRAGMAS
-  if( db->autoCommit ){
-    sqlite3BtreeSetSafetyLevel(pDb->pBt, pDb->safety_level,
-               (db->flags&SQLITE_FullFSync)!=0,
-               (db->flags&SQLITE_CkptFullFSync)!=0);
-  }
-#endif
 pragma_out:
   sqlite3DbFree(db, zLeft);
   sqlite3DbFree(db, zRight);
diff --git a/lib/libsqlite3/src/prepare.c b/lib/libsqlite3/src/prepare.c
index d78d83cbd87..cfc9c348551 100644
--- a/lib/libsqlite3/src/prepare.c
+++ b/lib/libsqlite3/src/prepare.c
@@ -592,7 +592,7 @@ static int sqlite3Prepare(
   sqlite3VtabUnlockList(db);
 
   pParse->db = db;
-  pParse->nQueryLoop = (double)1;
+  pParse->nQueryLoop = 0;  /* Logarithmic, so 0 really means 1 */
   if( nBytes>=0 && (nBytes==0 || zSql[nBytes-1]!=0) ){
     char *zSqlCopy;
     int mxLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH];
@@ -614,7 +614,7 @@ static int sqlite3Prepare(
   }else{
     sqlite3RunParser(pParse, zSql, &zErrMsg);
   }
-  assert( 1==(int)pParse->nQueryLoop );
+  assert( 0==pParse->nQueryLoop );
 
   if( db->mallocFailed ){
     pParse->rc = SQLITE_NOMEM;
@@ -810,6 +810,12 @@ static int sqlite3Prepare16(
   if( !sqlite3SafetyCheckOk(db) ){
     return SQLITE_MISUSE_BKPT;
   }
+  if( nBytes>=0 ){
+    int sz;
+    const char *z = (const char*)zSql;
+    for(sz=0; sz<nBytes && (z[sz]!=0 || z[sz+1]!=0); sz += 2){}
+    nBytes = sz;
+  }
   sqlite3_mutex_enter(db->mutex);
   zSql8 = sqlite3Utf16to8(db, zSql, nBytes, SQLITE_UTF16NATIVE);
   if( zSql8 ){
diff --git a/lib/libsqlite3/src/printf.c b/lib/libsqlite3/src/printf.c
index 9f68d204ffd..f9e5c6406d7 100644
--- a/lib/libsqlite3/src/printf.c
+++ b/lib/libsqlite3/src/printf.c
@@ -359,7 +359,7 @@ void sqlite3VXPrintf(
           nOut = precision + 10;
           zOut = zExtra = sqlite3Malloc( nOut );
           if( zOut==0 ){
-            pAccum->mallocFailed = 1;
+            pAccum->accError = STRACCUM_NOMEM;
             return;
           }
         }
@@ -413,13 +413,7 @@ void sqlite3VXPrintf(
           else                         prefix = 0;
         }
         if( xtype==etGENERIC && precision>0 ) precision--;
-#if 0
-        /* Rounding works like BSD when the constant 0.4999 is used.  Wierd! */
-        for(idx=precision, rounder=0.4999; idx>0; idx--, rounder*=0.1);
-#else
-        /* It makes more sense to use 0.5 */
         for(idx=precision, rounder=0.5; idx>0; idx--, rounder*=0.1){}
-#endif
         if( xtype==etFLOAT ) realvalue += rounder;
         /* Normalize realvalue to within 10.0 > realvalue >= 1.0 */
         exp = 0;
@@ -474,10 +468,10 @@ void sqlite3VXPrintf(
         }else{
           e2 = exp;
         }
-        if( e2+precision+width > etBUFSIZE - 15 ){
-          bufpt = zExtra = sqlite3Malloc( e2+precision+width+15 );
+        if( MAX(e2,0)+precision+width > etBUFSIZE - 15 ){
+          bufpt = zExtra = sqlite3Malloc( MAX(e2,0)+precision+width+15 );
           if( bufpt==0 ){
-            pAccum->mallocFailed = 1;
+            pAccum->accError = STRACCUM_NOMEM;
             return;
           }
         }
@@ -612,7 +606,7 @@ void sqlite3VXPrintf(
         if( n>etBUFSIZE ){
           bufpt = zExtra = sqlite3Malloc( n );
           if( bufpt==0 ){
-            pAccum->mallocFailed = 1;
+            pAccum->accError = STRACCUM_NOMEM;
             return;
           }
         }else{
@@ -690,22 +684,20 @@ void sqlite3VXPrintf(
 */
 void sqlite3StrAccumAppend(StrAccum *p, const char *z, int N){
   assert( z!=0 || N==0 );
-  if( p->tooBig | p->mallocFailed ){
-    testcase(p->tooBig);
-    testcase(p->mallocFailed);
+  if( p->accError ){
+    testcase(p->accError==STRACCUM_TOOBIG);
+    testcase(p->accError==STRACCUM_NOMEM);
     return;
   }
   assert( p->zText!=0 || p->nChar==0 );
-  if( N<0 ){
+  if( N<=0 ){
+    if( N==0 || z[0]==0 ) return;
     N = sqlite3Strlen30(z);
   }
-  if( N==0 || NEVER(z==0) ){
-    return;
-  }
   if( p->nChar+N >= p->nAlloc ){
     char *zNew;
     if( !p->useMalloc ){
-      p->tooBig = 1;
+      p->accError = STRACCUM_TOOBIG;
       N = p->nAlloc - p->nChar - 1;
       if( N<=0 ){
         return;
@@ -716,7 +708,7 @@ void sqlite3StrAccumAppend(StrAccum *p, const char *z, int N){
       szNew += N + 1;
       if( szNew > p->mxAlloc ){
         sqlite3StrAccumReset(p);
-        p->tooBig = 1;
+        p->accError = STRACCUM_TOOBIG;
         return;
       }else{
         p->nAlloc = (int)szNew;
@@ -730,7 +722,7 @@ void sqlite3StrAccumAppend(StrAccum *p, const char *z, int N){
         if( zOld==0 && p->nChar>0 ) memcpy(zNew, p->zText, p->nChar);
         p->zText = zNew;
       }else{
-        p->mallocFailed = 1;
+        p->accError = STRACCUM_NOMEM;
         sqlite3StrAccumReset(p);
         return;
       }
@@ -758,7 +750,7 @@ char *sqlite3StrAccumFinish(StrAccum *p){
       if( p->zText ){
         memcpy(p->zText, p->zBase, p->nChar+1);
       }else{
-        p->mallocFailed = 1;
+        p->accError = STRACCUM_NOMEM;
       }
     }
   }
@@ -789,8 +781,7 @@ void sqlite3StrAccumInit(StrAccum *p, char *zBase, int n, int mx){
   p->nAlloc = n;
   p->mxAlloc = mx;
   p->useMalloc = 1;
-  p->tooBig = 0;
-  p->mallocFailed = 0;
+  p->accError = 0;
 }
 
 /*
@@ -807,7 +798,7 @@ char *sqlite3VMPrintf(sqlite3 *db, const char *zFormat, va_list ap){
   acc.db = db;
   sqlite3VXPrintf(&acc, 1, zFormat, ap);
   z = sqlite3StrAccumFinish(&acc);
-  if( acc.mallocFailed ){
+  if( acc.accError==STRACCUM_NOMEM ){
     db->mallocFailed = 1;
   }
   return z;
diff --git a/lib/libsqlite3/src/resolve.c b/lib/libsqlite3/src/resolve.c
index 91efcaa1a16..43a3870e23e 100644
--- a/lib/libsqlite3/src/resolve.c
+++ b/lib/libsqlite3/src/resolve.c
@@ -55,7 +55,7 @@ static void incrAggFunctionDepth(Expr *pExpr, int N){
 ** column reference is so that the column reference will be recognized as
 ** usable by indices within the WHERE clause processing logic. 
 **
-** Hack:  The TK_AS operator is inhibited if zType[0]=='G'.  This means
+** The TK_AS operator is inhibited if zType[0]=='G'.  This means
 ** that in a GROUP BY clause, the expression is evaluated twice.  Hence:
 **
 **     SELECT random()%5 AS x, count(*) FROM tab GROUP BY x
@@ -65,8 +65,9 @@ static void incrAggFunctionDepth(Expr *pExpr, int N){
 **     SELECT random()%5 AS x, count(*) FROM tab GROUP BY random()%5
 **
 ** The result of random()%5 in the GROUP BY clause is probably different
-** from the result in the result-set.  We might fix this someday.  Or
-** then again, we might not...
+** from the result in the result-set.  On the other hand Standard SQL does
+** not allow the GROUP BY clause to contain references to result-set columns.
+** So this should never come up in well-formed queries.
 **
 ** If the reference is followed by a COLLATE operator, then make sure
 ** the COLLATE operator is preserved.  For example:
@@ -240,11 +241,20 @@ static int lookupName(
   ** resulting in an appropriate error message toward the end of this routine
   */
   if( zDb ){
-    for(i=0; i<db->nDb; i++){
-      assert( db->aDb[i].zName );
-      if( sqlite3StrICmp(db->aDb[i].zName,zDb)==0 ){
-        pSchema = db->aDb[i].pSchema;
-        break;
+    testcase( pNC->ncFlags & NC_PartIdx );
+    testcase( pNC->ncFlags & NC_IsCheck );
+    if( (pNC->ncFlags & (NC_PartIdx|NC_IsCheck))!=0 ){
+      /* Silently ignore database qualifiers inside CHECK constraints and partial
+      ** indices.  Do not raise errors because that might break legacy and
+      ** because it does not hurt anything to just ignore the database name. */
+      zDb = 0;
+    }else{
+      for(i=0; i<db->nDb; i++){
+        assert( db->aDb[i].zName );
+        if( sqlite3StrICmp(db->aDb[i].zName,zDb)==0 ){
+          pSchema = db->aDb[i].pSchema;
+          break;
+        }
       }
     }
   }
@@ -387,10 +397,16 @@ static int lookupName(
     ** forms the result set entry ("a+b" in the example) and return immediately.
     ** Note that the expression in the result set should have already been
     ** resolved by the time the WHERE clause is resolved.
+    **
+    ** The ability to use an output result-set column in the WHERE, GROUP BY,
+    ** or HAVING clauses, or as part of a larger expression in the ORDRE BY
+    ** clause is not standard SQL.  This is a (goofy) SQLite extension, that
+    ** is supported for backwards compatibility only.  TO DO: Issue a warning
+    ** on sqlite3_log() whenever the capability is used.
     */
     if( (pEList = pNC->pEList)!=0
      && zTab==0
-     && ((pNC->ncFlags & NC_AsMaybe)==0 || cnt==0)
+     && cnt==0
     ){
       for(j=0; j<pEList->nExpr; j++){
         char *zAs = pEList->a[j].zName;
@@ -523,6 +539,39 @@ Expr *sqlite3CreateColumnExpr(sqlite3 *db, SrcList *pSrc, int iSrc, int iCol){
 }
 
 /*
+** Report an error that an expression is not valid for a partial index WHERE
+** clause.
+*/
+static void notValidPartIdxWhere(
+  Parse *pParse,       /* Leave error message here */
+  NameContext *pNC,    /* The name context */
+  const char *zMsg     /* Type of error */
+){
+  if( (pNC->ncFlags & NC_PartIdx)!=0 ){
+    sqlite3ErrorMsg(pParse, "%s prohibited in partial index WHERE clauses",
+                    zMsg);
+  }
+}
+
+#ifndef SQLITE_OMIT_CHECK
+/*
+** Report an error that an expression is not valid for a CHECK constraint.
+*/
+static void notValidCheckConstraint(
+  Parse *pParse,       /* Leave error message here */
+  NameContext *pNC,    /* The name context */
+  const char *zMsg     /* Type of error */
+){
+  if( (pNC->ncFlags & NC_IsCheck)!=0 ){
+    sqlite3ErrorMsg(pParse,"%s prohibited in CHECK constraints", zMsg);
+  }
+}
+#else
+# define notValidCheckConstraint(P,N,M)
+#endif
+
+
+/*
 ** This routine is callback for sqlite3WalkExpr().
 **
 ** Resolve symbolic names into TK_COLUMN operators for the current
@@ -621,6 +670,7 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
 
       testcase( pExpr->op==TK_CONST_FUNC );
       assert( !ExprHasProperty(pExpr, EP_xIsSelect) );
+      notValidPartIdxWhere(pParse, pNC, "functions");
       zId = pExpr->u.zToken;
       nId = sqlite3Strlen30(zId);
       pDef = sqlite3FindFunction(pParse->db, zId, nId, n, enc, 0);
@@ -686,11 +736,8 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
       testcase( pExpr->op==TK_IN );
       if( ExprHasProperty(pExpr, EP_xIsSelect) ){
         int nRef = pNC->nRef;
-#ifndef SQLITE_OMIT_CHECK
-        if( (pNC->ncFlags & NC_IsCheck)!=0 ){
-          sqlite3ErrorMsg(pParse,"subqueries prohibited in CHECK constraints");
-        }
-#endif
+        notValidCheckConstraint(pParse, pNC, "subqueries");
+        notValidPartIdxWhere(pParse, pNC, "subqueries");
         sqlite3WalkSelect(pWalker, pExpr->x.pSelect);
         assert( pNC->nRef>=nRef );
         if( nRef!=pNC->nRef ){
@@ -699,14 +746,11 @@ static int resolveExprStep(Walker *pWalker, Expr *pExpr){
       }
       break;
     }
-#ifndef SQLITE_OMIT_CHECK
     case TK_VARIABLE: {
-      if( (pNC->ncFlags & NC_IsCheck)!=0 ){
-        sqlite3ErrorMsg(pParse,"parameters prohibited in CHECK constraints");
-      }
+      notValidCheckConstraint(pParse, pNC, "parameters");
+      notValidPartIdxWhere(pParse, pNC, "parameters");
       break;
     }
-#endif
   }
   return (pParse->nErr || pParse->db->mallocFailed) ? WRC_Abort : WRC_Continue;
 }
@@ -797,7 +841,7 @@ static int resolveOrderByTermToExprList(
   ** result-set entry.
   */
   for(i=0; i<pEList->nExpr; i++){
-    if( sqlite3ExprCompare(pEList->a[i].pExpr, pE)<2 ){
+    if( sqlite3ExprCompare(pEList->a[i].pExpr, pE, -1)<2 ){
       return i+1;
     }
   }
@@ -924,7 +968,7 @@ static int resolveCompoundOrderBy(
 /*
 ** Check every term in the ORDER BY or GROUP BY clause pOrderBy of
 ** the SELECT statement pSelect.  If any term is reference to a
-** result set expression (as determined by the ExprList.a.iCol field)
+** result set expression (as determined by the ExprList.a.iOrderByCol field)
 ** then convert that term into a copy of the corresponding result set
 ** column.
 **
@@ -972,7 +1016,7 @@ int sqlite3ResolveOrderGroupBy(
 ** If the order-by term is an integer I between 1 and N (where N is the
 ** number of columns in the result set of the SELECT) then the expression
 ** in the resolution is a copy of the I-th result-set expression.  If
-** the order-by term is an identify that corresponds to the AS-name of
+** the order-by term is an identifier that corresponds to the AS-name of
 ** a result-set expression, then the term resolves to a copy of the
 ** result-set expression.  Otherwise, the expression is resolved in
 ** the usual way - using sqlite3ResolveExprNames().
@@ -998,16 +1042,19 @@ static int resolveOrderGroupBy(
   pParse = pNC->pParse;
   for(i=0, pItem=pOrderBy->a; i<pOrderBy->nExpr; i++, pItem++){
     Expr *pE = pItem->pExpr;
-    iCol = resolveAsName(pParse, pSelect->pEList, pE);
-    if( iCol>0 ){
-      /* If an AS-name match is found, mark this ORDER BY column as being
-      ** a copy of the iCol-th result-set column.  The subsequent call to
-      ** sqlite3ResolveOrderGroupBy() will convert the expression to a
-      ** copy of the iCol-th result-set expression. */
-      pItem->iOrderByCol = (u16)iCol;
-      continue;
+    Expr *pE2 = sqlite3ExprSkipCollate(pE);
+    if( zType[0]!='G' ){
+      iCol = resolveAsName(pParse, pSelect->pEList, pE2);
+      if( iCol>0 ){
+        /* If an AS-name match is found, mark this ORDER BY column as being
+        ** a copy of the iCol-th result-set column.  The subsequent call to
+        ** sqlite3ResolveOrderGroupBy() will convert the expression to a
+        ** copy of the iCol-th result-set expression. */
+        pItem->iOrderByCol = (u16)iCol;
+        continue;
+      }
     }
-    if( sqlite3ExprIsInteger(sqlite3ExprSkipCollate(pE), &iCol) ){
+    if( sqlite3ExprIsInteger(pE2, &iCol) ){
       /* The ORDER BY term is an integer constant.  Again, set the column
       ** number so that sqlite3ResolveOrderGroupBy() will convert the
       ** order-by term to a copy of the result-set expression */
@@ -1025,7 +1072,7 @@ static int resolveOrderGroupBy(
       return 1;
     }
     for(j=0; j<pSelect->pEList->nExpr; j++){
-      if( sqlite3ExprCompare(pE, pSelect->pEList->a[j].pExpr)==0 ){
+      if( sqlite3ExprCompare(pE, pSelect->pEList->a[j].pExpr, -1)==0 ){
         pItem->iOrderByCol = j+1;
       }
     }
@@ -1150,7 +1197,7 @@ static int resolveSelectStep(Walker *pWalker, Select *p){
       return WRC_Abort;
     }
   
-    /* Add the expression list to the name-context before parsing the
+    /* Add the output column list to the name-context before parsing the
     ** other expressions in the SELECT statement. This is so that
     ** expressions in the WHERE clause (etc.) can refer to expressions by
     ** aliases in the result set.
@@ -1159,10 +1206,8 @@ static int resolveSelectStep(Walker *pWalker, Select *p){
     ** re-evaluated for each reference to it.
     */
     sNC.pEList = p->pEList;
-    sNC.ncFlags |= NC_AsMaybe;
     if( sqlite3ResolveExprNames(&sNC, p->pHaving) ) return WRC_Abort;
     if( sqlite3ResolveExprNames(&sNC, p->pWhere) ) return WRC_Abort;
-    sNC.ncFlags &= ~NC_AsMaybe;
 
     /* The ORDER BY and GROUP BY clauses may not refer to terms in
     ** outer queries 
@@ -1331,3 +1376,45 @@ void sqlite3ResolveSelectNames(
   w.u.pNC = pOuterNC;
   sqlite3WalkSelect(&w, p);
 }
+
+/*
+** Resolve names in expressions that can only reference a single table:
+**
+**    *   CHECK constraints
+**    *   WHERE clauses on partial indices
+**
+** The Expr.iTable value for Expr.op==TK_COLUMN nodes of the expression
+** is set to -1 and the Expr.iColumn value is set to the column number.
+**
+** Any errors cause an error message to be set in pParse.
+*/
+void sqlite3ResolveSelfReference(
+  Parse *pParse,      /* Parsing context */
+  Table *pTab,        /* The table being referenced */
+  int type,           /* NC_IsCheck or NC_PartIdx */
+  Expr *pExpr,        /* Expression to resolve.  May be NULL. */
+  ExprList *pList     /* Expression list to resolve.  May be NUL. */
+){
+  SrcList sSrc;                   /* Fake SrcList for pParse->pNewTable */
+  NameContext sNC;                /* Name context for pParse->pNewTable */
+  int i;                          /* Loop counter */
+
+  assert( type==NC_IsCheck || type==NC_PartIdx );
+  memset(&sNC, 0, sizeof(sNC));
+  memset(&sSrc, 0, sizeof(sSrc));
+  sSrc.nSrc = 1;
+  sSrc.a[0].zName = pTab->zName;
+  sSrc.a[0].pTab = pTab;
+  sSrc.a[0].iCursor = -1;
+  sNC.pParse = pParse;
+  sNC.pSrcList = &sSrc;
+  sNC.ncFlags = type;
+  if( sqlite3ResolveExprNames(&sNC, pExpr) ) return;
+  if( pList ){
+    for(i=0; i<pList->nExpr; i++){
+      if( sqlite3ResolveExprNames(&sNC, pList->a[i].pExpr) ){
+        return;
+      }
+    }
+  }
+}
diff --git a/lib/libsqlite3/src/select.c b/lib/libsqlite3/src/select.c
index f3f14909639..83fcf7ed406 100644
--- a/lib/libsqlite3/src/select.c
+++ b/lib/libsqlite3/src/select.c
@@ -109,7 +109,7 @@ void sqlite3SelectDelete(sqlite3 *db, Select *p){
 }
 
 /*
-** Given 1 to 3 identifiers preceeding the JOIN keyword, determine the
+** Given 1 to 3 identifiers preceding the JOIN keyword, determine the
 ** type of join.  Return an integer constant that expresses that type
 ** in terms of the following bit values:
 **
@@ -803,6 +803,25 @@ static void selectInnerLoop(
 }
 
 /*
+** Allocate a KeyInfo object sufficient for an index of N columns.
+**
+** Actually, always allocate one extra column for the rowid at the end
+** of the index.  So the KeyInfo returned will have space sufficient for
+** N+1 columns.
+*/
+KeyInfo *sqlite3KeyInfoAlloc(sqlite3 *db, int N){
+  KeyInfo *p = sqlite3DbMallocZero(db, 
+                   sizeof(KeyInfo) + (N+1)*(sizeof(CollSeq*)+1));
+  if( p ){
+    p->aSortOrder = (u8*)&p->aColl[N+1];
+    p->nField = (u16)N;
+    p->enc = ENC(db);
+    p->db = db;
+  }
+  return p;
+}
+
+/*
 ** Given an expression list, generate a KeyInfo structure that records
 ** the collating sequence for each expression in that expression list.
 **
@@ -818,25 +837,19 @@ static void selectInnerLoop(
 ** P4_KEYINFO_HANDOFF is the usual way of dealing with this.
 */
 static KeyInfo *keyInfoFromExprList(Parse *pParse, ExprList *pList){
-  sqlite3 *db = pParse->db;
   int nExpr;
   KeyInfo *pInfo;
   struct ExprList_item *pItem;
+  sqlite3 *db = pParse->db;
   int i;
 
   nExpr = pList->nExpr;
-  pInfo = sqlite3DbMallocZero(db, sizeof(*pInfo) + nExpr*(sizeof(CollSeq*)+1) );
+  pInfo = sqlite3KeyInfoAlloc(db, nExpr);
   if( pInfo ){
-    pInfo->aSortOrder = (u8*)&pInfo->aColl[nExpr];
-    pInfo->nField = (u16)nExpr;
-    pInfo->enc = ENC(db);
-    pInfo->db = db;
     for(i=0, pItem=pList->a; i<nExpr; i++, pItem++){
       CollSeq *pColl;
       pColl = sqlite3ExprCollSeq(pParse, pItem->pExpr);
-      if( !pColl ){
-        pColl = db->pDfltColl;
-      }
+      if( !pColl ) pColl = db->pDfltColl;
       pInfo->aColl[i] = pColl;
       pInfo->aSortOrder[i] = pItem->sortOrder;
     }
@@ -1523,7 +1536,7 @@ static void computeLimitRegisters(Parse *pParse, Select *p, int iBreak){
 
   /* 
   ** "LIMIT -1" always shows all rows.  There is some
-  ** contraversy about what the correct behavior should be.
+  ** controversy about what the correct behavior should be.
   ** The current implementation interprets "LIMIT 0" to mean
   ** no rows.
   */
@@ -1538,8 +1551,8 @@ static void computeLimitRegisters(Parse *pParse, Select *p, int iBreak){
       VdbeComment((v, "LIMIT counter"));
       if( n==0 ){
         sqlite3VdbeAddOp2(v, OP_Goto, 0, iBreak);
-      }else{
-        if( p->nSelectRow > (double)n ) p->nSelectRow = (double)n;
+      }else if( n>=0 && p->nSelectRow>(u64)n ){
+        p->nSelectRow = n;
       }
     }else{
       sqlite3ExprCode(pParse, p->pLimit, iLimit);
@@ -1733,9 +1746,9 @@ static int multiSelect(
       p->nSelectRow += pPrior->nSelectRow;
       if( pPrior->pLimit
        && sqlite3ExprIsInteger(pPrior->pLimit, &nLimit)
-       && p->nSelectRow > (double)nLimit 
+       && nLimit>0 && p->nSelectRow > (u64)nLimit 
       ){
-        p->nSelectRow = (double)nLimit;
+        p->nSelectRow = nLimit;
       }
       if( addr ){
         sqlite3VdbeJumpHere(v, addr);
@@ -1942,23 +1955,17 @@ static int multiSelect(
 
     assert( p->pRightmost==p );
     nCol = p->pEList->nExpr;
-    pKeyInfo = sqlite3DbMallocZero(db,
-                       sizeof(*pKeyInfo)+nCol*(sizeof(CollSeq*) + 1));
+    pKeyInfo = sqlite3KeyInfoAlloc(db, nCol);
     if( !pKeyInfo ){
       rc = SQLITE_NOMEM;
       goto multi_select_end;
     }
-
-    pKeyInfo->enc = ENC(db);
-    pKeyInfo->nField = (u16)nCol;
-
     for(i=0, apColl=pKeyInfo->aColl; i<nCol; i++, apColl++){
       *apColl = multiSelectCollSeq(pParse, p, i);
       if( 0==*apColl ){
         *apColl = db->pDfltColl;
       }
     }
-    pKeyInfo->aSortOrder = (u8*)apColl;
 
     for(pLoop=p; pLoop; pLoop=pLoop->pPrior){
       for(i=0; i<2; i++){
@@ -2327,12 +2334,8 @@ static int multiSelectOrderBy(
       assert( pItem->iOrderByCol>0  && pItem->iOrderByCol<=p->pEList->nExpr );
       aPermute[i] = pItem->iOrderByCol - 1;
     }
-    pKeyMerge =
-      sqlite3DbMallocRaw(db, sizeof(*pKeyMerge)+nOrderBy*(sizeof(CollSeq*)+1));
+    pKeyMerge = sqlite3KeyInfoAlloc(db, nOrderBy);
     if( pKeyMerge ){
-      pKeyMerge->aSortOrder = (u8*)&pKeyMerge->aColl[nOrderBy];
-      pKeyMerge->nField = (u16)nOrderBy;
-      pKeyMerge->enc = ENC(db);
       for(i=0; i<nOrderBy; i++){
         CollSeq *pColl;
         Expr *pTerm = pOrderBy->a[i].pExpr;
@@ -2369,12 +2372,8 @@ static int multiSelectOrderBy(
     regPrev = pParse->nMem+1;
     pParse->nMem += nExpr+1;
     sqlite3VdbeAddOp2(v, OP_Integer, 0, regPrev);
-    pKeyDup = sqlite3DbMallocZero(db,
-                  sizeof(*pKeyDup) + nExpr*(sizeof(CollSeq*)+1) );
+    pKeyDup = sqlite3KeyInfoAlloc(db, nExpr);
     if( pKeyDup ){
-      pKeyDup->aSortOrder = (u8*)&pKeyDup->aColl[nExpr];
-      pKeyDup->nField = (u16)nExpr;
-      pKeyDup->enc = ENC(db);
       for(i=0; i<nExpr; i++){
         pKeyDup->aColl[i] = multiSelectCollSeq(pParse, p, i);
         pKeyDup->aSortOrder[i] = 0;
@@ -3640,10 +3639,12 @@ static int exprWalkNoop(Walker *NotUsed, Expr *NotUsed2){
 static void sqlite3SelectExpand(Parse *pParse, Select *pSelect){
   Walker w;
   memset(&w, 0, sizeof(w));
-  w.xSelectCallback = convertCompoundSelectToSubquery;
   w.xExprCallback = exprWalkNoop;
   w.pParse = pParse;
-  sqlite3WalkSelect(&w, pSelect);
+  if( pParse->hasCompound ){
+    w.xSelectCallback = convertCompoundSelectToSubquery;
+    sqlite3WalkSelect(&w, pSelect);
+  }
   w.xSelectCallback = selectExpander;
   sqlite3WalkSelect(&w, pSelect);
 }
@@ -3884,11 +3885,10 @@ static void explainSimpleCount(
   Index *pIdx                     /* Index used to optimize scan, or NULL */
 ){
   if( pParse->explain==2 ){
-    char *zEqp = sqlite3MPrintf(pParse->db, "SCAN TABLE %s %s%s(~%d rows)",
+    char *zEqp = sqlite3MPrintf(pParse->db, "SCAN TABLE %s%s%s",
         pTab->zName, 
-        pIdx ? "USING COVERING INDEX " : "",
-        pIdx ? pIdx->zName : "",
-        pTab->nRowEst
+        pIdx ? " USING COVERING INDEX " : "",
+        pIdx ? pIdx->zName : ""
     );
     sqlite3VdbeAddOp4(
         pParse->pVdbe, OP_Explain, pParse->iSelectId, 0, 0, zEqp, P4_DYNAMIC
@@ -4046,7 +4046,7 @@ int sqlite3Select(
     }
 
     /* Increment Parse.nHeight by the height of the largest expression
-    ** tree refered to by this, the parent select. The child select
+    ** tree referred to by this, the parent select. The child select
     ** may contain expression trees of at most
     ** (SQLITE_MAX_EXPR_DEPTH-Parse.nHeight) height. This is a bit
     ** more conservative than necessary, but much easier than enforcing
@@ -4178,7 +4178,7 @@ int sqlite3Select(
   ** Use the SQLITE_GroupByOrder flag with SQLITE_TESTCTRL_OPTIMIZER
   ** to disable this optimization for testing purposes.
   */
-  if( sqlite3ExprListCompare(p->pGroupBy, pOrderBy)==0
+  if( sqlite3ExprListCompare(p->pGroupBy, pOrderBy, -1)==0
          && OptimizationEnabled(db, SQLITE_GroupByOrder) ){
     pOrderBy = 0;
   }
@@ -4199,7 +4199,7 @@ int sqlite3Select(
   ** BY and DISTINCT, and an index or separate temp-table for the other.
   */
   if( (p->selFlags & (SF_Distinct|SF_Aggregate))==SF_Distinct 
-   && sqlite3ExprListCompare(pOrderBy, p->pEList)==0
+   && sqlite3ExprListCompare(pOrderBy, p->pEList, -1)==0
   ){
     p->selFlags &= ~SF_Distinct;
     p->pGroupBy = sqlite3ExprListDup(db, p->pEList, 0);
@@ -4239,7 +4239,7 @@ int sqlite3Select(
   /* Set the limiter.
   */
   iEnd = sqlite3VdbeMakeLabel(v);
-  p->nSelectRow = (double)LARGEST_INT64;
+  p->nSelectRow = LARGEST_INT64;
   computeLimitRegisters(pParse, p, iEnd);
   if( p->iLimit==0 && addrSortIndex>=0 ){
     sqlite3VdbeGetOp(v, addrSortIndex)->opcode = OP_SorterOpen;
@@ -4262,14 +4262,19 @@ int sqlite3Select(
 
   if( !isAgg && pGroupBy==0 ){
     /* No aggregate functions and no GROUP BY clause */
-    ExprList *pDist = (sDistinct.isTnct ? p->pEList : 0);
+    u16 wctrlFlags = (sDistinct.isTnct ? WHERE_WANT_DISTINCT : 0);
 
     /* Begin the database scan. */
-    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pOrderBy, pDist, 0,0);
+    pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pOrderBy, p->pEList,
+                               wctrlFlags, 0);
     if( pWInfo==0 ) goto select_end;
-    if( pWInfo->nRowOut < p->nSelectRow ) p->nSelectRow = pWInfo->nRowOut;
-    if( pWInfo->eDistinct ) sDistinct.eTnctType = pWInfo->eDistinct;
-    if( pOrderBy && pWInfo->nOBSat==pOrderBy->nExpr ) pOrderBy = 0;
+    if( sqlite3WhereOutputRowCount(pWInfo) < p->nSelectRow ){
+      p->nSelectRow = sqlite3WhereOutputRowCount(pWInfo);
+    }
+    if( sDistinct.isTnct && sqlite3WhereIsDistinct(pWInfo) ){
+      sDistinct.eTnctType = sqlite3WhereIsDistinct(pWInfo);
+    }
+    if( pOrderBy && sqlite3WhereIsOrdered(pWInfo) ) pOrderBy = 0;
 
     /* If sorting index that was created by a prior OP_OpenEphemeral 
     ** instruction ended up not being needed, then change the OP_OpenEphemeral
@@ -4282,7 +4287,8 @@ int sqlite3Select(
 
     /* Use the standard inner loop. */
     selectInnerLoop(pParse, p, pEList, 0, 0, pOrderBy, &sDistinct, pDest,
-                    pWInfo->iContinue, pWInfo->iBreak);
+                    sqlite3WhereContinueLabel(pWInfo),
+                    sqlite3WhereBreakLabel(pWInfo));
 
     /* End the database scan loop.
     */
@@ -4315,9 +4321,9 @@ int sqlite3Select(
       for(k=pGroupBy->nExpr, pItem=pGroupBy->a; k>0; k--, pItem++){
         pItem->iAlias = 0;
       }
-      if( p->nSelectRow>(double)100 ) p->nSelectRow = (double)100;
+      if( p->nSelectRow>100 ) p->nSelectRow = 100;
     }else{
-      p->nSelectRow = (double)1;
+      p->nSelectRow = 1;
     }
 
  
@@ -4397,9 +4403,10 @@ int sqlite3Select(
       ** in the right order to begin with.
       */
       sqlite3VdbeAddOp2(v, OP_Gosub, regReset, addrReset);
-      pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pGroupBy, 0, 0, 0);
+      pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pGroupBy, 0, 
+                                 WHERE_GROUPBY, 0);
       if( pWInfo==0 ) goto select_end;
-      if( pWInfo->nOBSat==pGroupBy->nExpr ){
+      if( sqlite3WhereIsOrdered(pWInfo) ){
         /* The optimizer is able to deliver rows in group by order so
         ** we do not have to sort.  The OP_OpenEphemeral table will be
         ** cancelled later because we still need to use the pKeyInfo
@@ -4680,8 +4687,8 @@ int sqlite3Select(
         }
         updateAccumulator(pParse, &sAggInfo);
         assert( pMinMax==0 || pMinMax->nExpr==1 );
-        if( pWInfo->nOBSat>0 ){
-          sqlite3VdbeAddOp2(v, OP_Goto, 0, pWInfo->iBreak);
+        if( sqlite3WhereIsOrdered(pWInfo) ){
+          sqlite3VdbeAddOp2(v, OP_Goto, 0, sqlite3WhereBreakLabel(pWInfo));
           VdbeComment((v, "%s() by index",
                 (flag==WHERE_ORDERBY_MIN?"min":"max")));
         }
diff --git a/lib/libsqlite3/src/sqlite.h.in b/lib/libsqlite3/src/sqlite.h.in
index 6608823175d..fc76029bcba 100644
--- a/lib/libsqlite3/src/sqlite.h.in
+++ b/lib/libsqlite3/src/sqlite.h.in
@@ -473,8 +473,10 @@ int sqlite3_exec(
 #define SQLITE_IOERR_SEEK              (SQLITE_IOERR | (22<<8))
 #define SQLITE_IOERR_DELETE_NOENT      (SQLITE_IOERR | (23<<8))
 #define SQLITE_IOERR_MMAP              (SQLITE_IOERR | (24<<8))
+#define SQLITE_IOERR_GETTEMPPATH       (SQLITE_IOERR | (25<<8))
 #define SQLITE_LOCKED_SHAREDCACHE      (SQLITE_LOCKED |  (1<<8))
 #define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
+#define SQLITE_BUSY_SNAPSHOT           (SQLITE_BUSY   |  (2<<8))
 #define SQLITE_CANTOPEN_NOTEMPDIR      (SQLITE_CANTOPEN | (1<<8))
 #define SQLITE_CANTOPEN_ISDIR          (SQLITE_CANTOPEN | (2<<8))
 #define SQLITE_CANTOPEN_FULLPATH       (SQLITE_CANTOPEN | (3<<8))
@@ -494,6 +496,7 @@ int sqlite3_exec(
 #define SQLITE_CONSTRAINT_VTAB         (SQLITE_CONSTRAINT | (9<<8))
 #define SQLITE_NOTICE_RECOVER_WAL      (SQLITE_NOTICE | (1<<8))
 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
+#define SQLITE_WARNING_AUTOINDEX       (SQLITE_WARNING | (1<<8))
 
 /*
 ** CAPI3REF: Flags For File Open Operations
@@ -2552,9 +2555,10 @@ SQLITE_EXPERIMENTAL void *sqlite3_profile(sqlite3*,
 ** interface is to keep a GUI updated during a large query.
 **
 ** ^The parameter P is passed through as the only parameter to the 
-** callback function X.  ^The parameter N is the number of 
+** callback function X.  ^The parameter N is the approximate number of 
 ** [virtual machine instructions] that are evaluated between successive
-** invocations of the callback X.
+** invocations of the callback X.  ^If N is less than one then the progress
+** handler is disabled.
 **
 ** ^Only a single progress handler may be defined at one time per
 ** [database connection]; setting a new progress handler cancels the
@@ -4174,41 +4178,49 @@ sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
 /*
 ** CAPI3REF: Function Auxiliary Data
 **
-** The following two functions may be used by scalar SQL functions to
+** These functions may be used by (non-aggregate) SQL functions to
 ** associate metadata with argument values. If the same value is passed to
 ** multiple invocations of the same SQL function during query execution, under
-** some circumstances the associated metadata may be preserved. This may
-** be used, for example, to add a regular-expression matching scalar
-** function. The compiled version of the regular expression is stored as
-** metadata associated with the SQL value passed as the regular expression
-** pattern.  The compiled regular expression can be reused on multiple
-** invocations of the same function so that the original pattern string
-** does not need to be recompiled on each invocation.
+** some circumstances the associated metadata may be preserved.  An example
+** of where this might be useful is in a regular-expression matching
+** function. The compiled version of the regular expression can be stored as
+** metadata associated with the pattern string.  
+** Then as long as the pattern string remains the same,
+** the compiled regular expression can be reused on multiple
+** invocations of the same function.
 **
 ** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata
 ** associated by the sqlite3_set_auxdata() function with the Nth argument
-** value to the application-defined function. ^If no metadata has been ever
-** been set for the Nth argument of the function, or if the corresponding
-** function parameter has changed since the meta-data was set,
-** then sqlite3_get_auxdata() returns a NULL pointer.
-**
-** ^The sqlite3_set_auxdata() interface saves the metadata
-** pointed to by its 3rd parameter as the metadata for the N-th
-** argument of the application-defined function.  Subsequent
-** calls to sqlite3_get_auxdata() might return this data, if it has
-** not been destroyed.
-** ^If it is not NULL, SQLite will invoke the destructor
-** function given by the 4th parameter to sqlite3_set_auxdata() on
-** the metadata when the corresponding function parameter changes
-** or when the SQL statement completes, whichever comes first.
-**
-** SQLite is free to call the destructor and drop metadata on any
-** parameter of any function at any time.  ^The only guarantee is that
-** the destructor will be called before the metadata is dropped.
+** value to the application-defined function. ^If there is no metadata
+** associated with the function argument, this sqlite3_get_auxdata() interface
+** returns a NULL pointer.
+**
+** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
+** argument of the application-defined function.  ^Subsequent
+** calls to sqlite3_get_auxdata(C,N) return P from the most recent
+** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
+** NULL if the metadata has been discarded.
+** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
+** SQLite will invoke the destructor function X with parameter P exactly
+** once, when the metadata is discarded.
+** SQLite is free to discard the metadata at any time, including: <ul>
+** <li> when the corresponding function parameter changes, or
+** <li> when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
+**      SQL statement, or
+** <li> when sqlite3_set_auxdata() is invoked again on the same parameter, or
+** <li> during the original sqlite3_set_auxdata() call when a memory 
+**      allocation error occurs. </ul>)^
+**
+** Note the last bullet in particular.  The destructor X in 
+** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
+** sqlite3_set_auxdata() interface even returns.  Hence sqlite3_set_auxdata()
+** should be called near the end of the function implementation and the
+** function implementation should not make any use of P after
+** sqlite3_set_auxdata() has been called.
 **
 ** ^(In practice, metadata is preserved between function calls for
-** expressions that are constant at compile time. This includes literal
-** values and [parameters].)^
+** function parameters that are compile-time constants, including literal
+** values and [parameters] and expressions composed from the same.)^
 **
 ** These routines must be called from the same thread in which
 ** the SQL function is running.
@@ -4513,6 +4525,11 @@ int sqlite3_key(
   sqlite3 *db,                   /* Database to be rekeyed */
   const void *pKey, int nKey     /* The key */
 );
+int sqlite3_key_v2(
+  sqlite3 *db,                   /* Database to be rekeyed */
+  const char *zDbName,           /* Name of the database */
+  const void *pKey, int nKey     /* The key */
+);
 
 /*
 ** Change the key on an open database.  If the current database is not
@@ -4526,6 +4543,11 @@ int sqlite3_rekey(
   sqlite3 *db,                   /* Database to be rekeyed */
   const void *pKey, int nKey     /* The new key */
 );
+int sqlite3_rekey_v2(
+  sqlite3 *db,                   /* Database to be rekeyed */
+  const char *zDbName,           /* Name of the database */
+  const void *pKey, int nKey     /* The new key */
+);
 
 /*
 ** Specify the activation key for a SEE database.  Unless 
@@ -5111,11 +5133,24 @@ int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
 ** on the list of automatic extensions is a harmless no-op. ^No entry point
 ** will be called more than once for each database connection that is opened.
 **
-** See also: [sqlite3_reset_auto_extension()].
+** See also: [sqlite3_reset_auto_extension()]
+** and [sqlite3_cancel_auto_extension()]
 */
 int sqlite3_auto_extension(void (*xEntryPoint)(void));
 
 /*
+** CAPI3REF: Cancel Automatic Extension Loading
+**
+** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
+** initialization routine X that was registered using a prior call to
+** [sqlite3_auto_extension(X)].  ^The [sqlite3_cancel_auto_extension(X)]
+** routine returns 1 if initialization routine X was successfully 
+** unregistered and it returns 0 if X was not on the list of initialization
+** routines.
+*/
+int sqlite3_cancel_auto_extension(void (*xEntryPoint)(void));
+
+/*
 ** CAPI3REF: Reset Automatic Extension Loading
 **
 ** ^This interface disables all automatic extensions previously
@@ -6227,6 +6262,12 @@ int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
 ** </dd>
+**
+** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
+** <dd>This parameter returns zero for the current value if and only if
+** all foreign key constraints (deferred or immediate) have been
+** resolved.)^  ^The highwater mark is always 0.
+** </dd>
 ** </dl>
 */
 #define SQLITE_DBSTATUS_LOOKASIDE_USED       0
@@ -6239,7 +6280,8 @@ int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
 #define SQLITE_DBSTATUS_CACHE_HIT            7
 #define SQLITE_DBSTATUS_CACHE_MISS           8
 #define SQLITE_DBSTATUS_CACHE_WRITE          9
-#define SQLITE_DBSTATUS_MAX                  9   /* Largest defined DBSTATUS */
+#define SQLITE_DBSTATUS_DEFERRED_FKS        10
+#define SQLITE_DBSTATUS_MAX                 10   /* Largest defined DBSTATUS */
 
 
 /*
@@ -6293,11 +6335,21 @@ int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
 ** A non-zero value in this counter may indicate an opportunity to
 ** improvement performance by adding permanent indices that do not
 ** need to be reinitialized each time the statement is run.</dd>
+**
+** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
+** <dd>^This is the number of virtual machine operations executed
+** by the prepared statement if that number is less than or equal
+** to 2147483647.  The number of virtual machine operations can be 
+** used as a proxy for the total work done by the prepared statement.
+** If the number of virtual machine operations exceeds 2147483647
+** then the value returned by this statement status code is undefined.
+** </dd>
 ** </dl>
 */
 #define SQLITE_STMTSTATUS_FULLSCAN_STEP     1
 #define SQLITE_STMTSTATUS_SORT              2
 #define SQLITE_STMTSTATUS_AUTOINDEX         3
+#define SQLITE_STMTSTATUS_VM_STEP           4
 
 /*
 ** CAPI3REF: Custom Page Cache Object
@@ -7176,4 +7228,4 @@ int sqlite3_vtab_on_conflict(sqlite3 *);
 #ifdef __cplusplus
 }  /* End of the 'extern "C"' block */
 #endif
-#endif
+#endif /* _SQLITE3_H_ */
diff --git a/lib/libsqlite3/src/sqlite3ext.h b/lib/libsqlite3/src/sqlite3ext.h
index 928bb3bad9d..ecf93f62f6c 100644
--- a/lib/libsqlite3/src/sqlite3ext.h
+++ b/lib/libsqlite3/src/sqlite3ext.h
@@ -474,11 +474,14 @@ struct sqlite3_api_routines {
   ** extension */
 # define SQLITE_EXTENSION_INIT1     const sqlite3_api_routines *sqlite3_api=0;
 # define SQLITE_EXTENSION_INIT2(v)  sqlite3_api=v;
+# define SQLITE_EXTENSION_INIT3     \
+    extern const sqlite3_api_routines *sqlite3_api;
 #else
   /* This case when the file is being statically linked into the 
   ** application */
 # define SQLITE_EXTENSION_INIT1     /*no-op*/
 # define SQLITE_EXTENSION_INIT2(v)  (void)v; /* unused parameter */
+# define SQLITE_EXTENSION_INIT3     /*no-op*/
 #endif
 
 #endif /* _SQLITE3EXT_H_ */
diff --git a/lib/libsqlite3/src/sqliteInt.h b/lib/libsqlite3/src/sqliteInt.h
index 5950f237d9f..025bb466d50 100644
--- a/lib/libsqlite3/src/sqliteInt.h
+++ b/lib/libsqlite3/src/sqliteInt.h
@@ -114,7 +114,7 @@
 ** The SQLITE_THREADSAFE macro must be defined as 0, 1, or 2.
 ** 0 means mutexes are permanently disable and the library is never
 ** threadsafe.  1 means the library is serialized which is the highest
-** level of threadsafety.  2 means the libary is multithreaded - multiple
+** level of threadsafety.  2 means the library is multithreaded - multiple
 ** threads can use SQLite as long as no two threads try to use the same
 ** database connection at the same time.
 **
@@ -161,9 +161,6 @@
 ** will cause HeapValidate to be called.  If heap validation should fail, an
 ** assertion will be triggered.
 **
-** (Historical note:  There used to be several other options, but we've
-** pared it down to just these three.)
-**
 ** If none of the above are defined, then set SQLITE_SYSTEM_MALLOC as
 ** the default.
 */
@@ -193,27 +190,12 @@
 
 /*
 ** We need to define _XOPEN_SOURCE as follows in order to enable
-** recursive mutexes on most Unix systems.  But Mac OS X is different.
-** The _XOPEN_SOURCE define causes problems for Mac OS X we are told,
-** so it is omitted there.  See ticket #2673.
-**
-** Later we learn that _XOPEN_SOURCE is poorly or incorrectly
-** implemented on some systems.  So we avoid defining it at all
-** if it is already defined or if it is unneeded because we are
-** not doing a threadsafe build.  Ticket #2681.
-**
-** See also ticket #2741.
+** recursive mutexes on most Unix systems and fchmod() on OpenBSD.
+** But _XOPEN_SOURCE define causes problems for Mac OS X, so omit
+** it.
 */
-#if !defined(_XOPEN_SOURCE) && !defined(__DARWIN__) \
- && !defined(__APPLE__) && SQLITE_THREADSAFE
-#  define _XOPEN_SOURCE 500  /* Needed to enable pthread recursive mutexes */
-#endif
-
-/*
-** The TCL headers are only needed when compiling the TCL bindings.
-*/
-#if defined(SQLITE_TCL) || defined(TCLSH)
-# include <tcl.h>
+#if !defined(_XOPEN_SOURCE) && !defined(__DARWIN__) && !defined(__APPLE__)
+#  define _XOPEN_SOURCE 600
 #endif
 
 /*
@@ -221,8 +203,8 @@
 ** defined(NDEBUG)==!defined(SQLITE_DEBUG).  If this is not currently true,
 ** make it true by defining or undefining NDEBUG.
 **
-** Setting NDEBUG makes the code smaller and run faster by disabling the
-** number assert() statements in the code.  So we want the default action
+** Setting NDEBUG makes the code smaller and faster by disabling the
+** assert() statements in the code.  So we want the default action
 ** to be for NDEBUG to be set and NDEBUG to be undefined only if SQLITE_DEBUG
 ** is set.  Thus NDEBUG becomes an opt-in rather than an opt-out
 ** feature.
@@ -292,7 +274,7 @@
 ** In other words, ALWAYS and NEVER are added for defensive code.
 **
 ** When doing coverage testing ALWAYS and NEVER are hard-coded to
-** be true and false so that the unreachable code then specify will
+** be true and false so that the unreachable code they specify will
 ** not be counted as untested code.
 */
 #if defined(SQLITE_COVERAGE_TEST)
@@ -316,16 +298,12 @@
 /*
 ** The macro unlikely() is a hint that surrounds a boolean
 ** expression that is usually false.  Macro likely() surrounds
-** a boolean expression that is usually true.  GCC is able to
-** use these hints to generate better code, sometimes.
+** a boolean expression that is usually true.  These hints could,
+** in theory, be used by the compiler to generate better code, but
+** currently they are just comments for human readers.
 */
-#if defined(__GNUC__) && 0
-# define likely(X)    __builtin_expect((X),1)
-# define unlikely(X)  __builtin_expect((X),0)
-#else
-# define likely(X)    !!(X)
-# define unlikely(X)  !!(X)
-#endif
+#define likely(X)    (X)
+#define unlikely(X)  (X)
 
 #include "sqlite3.h"
 #include "hash.h"
@@ -404,6 +382,12 @@
 #endif
 
 /*
+** Macros to compute minimum and maximum of two numbers.
+*/
+#define MIN(A,B) ((A)<(B)?(A):(B))
+#define MAX(A,B) ((A)>(B)?(A):(B))
+
+/*
 ** Check to see if this machine uses EBCDIC.  (Yes, believe it or
 ** not, there are still machines out there that use EBCDIC.)
 */
@@ -728,9 +712,7 @@ typedef struct UnpackedRecord UnpackedRecord;
 typedef struct VTable VTable;
 typedef struct VtabCtx VtabCtx;
 typedef struct Walker Walker;
-typedef struct WherePlan WherePlan;
 typedef struct WhereInfo WhereInfo;
-typedef struct WhereLevel WhereLevel;
 
 /*
 ** Defer sourcing vdbe.h and btree.h until after the "u8" and 
@@ -756,7 +738,6 @@ typedef struct WhereLevel WhereLevel;
 struct Db {
   char *zName;         /* Name of this database */
   Btree *pBt;          /* The B*Tree structure for this database file */
-  u8 inTrans;          /* 0: not writable.  1: Transaction.  2: Checkpoint */
   u8 safety_level;     /* How aggressive at syncing data to disk */
   Schema *pSchema;     /* Pointer to database schema (possibly shared) */
 };
@@ -902,9 +883,10 @@ struct sqlite3 {
     u8 busy;                    /* TRUE if currently initializing */
     u8 orphanTrigger;           /* Last statement is orphaned TEMP trigger */
   } init;
-  int activeVdbeCnt;            /* Number of VDBEs currently executing */
-  int writeVdbeCnt;             /* Number of active VDBEs that are writing */
-  int vdbeExecCnt;              /* Number of nested calls to VdbeExec() */
+  int nVdbeActive;              /* Number of VDBEs currently running */
+  int nVdbeRead;                /* Number of active VDBEs that read or write */
+  int nVdbeWrite;               /* Number of active VDBEs that read and write */
+  int nVdbeExec;                /* Number of nested calls to VdbeExec() */
   int nExtension;               /* Number of loaded extensions */
   void **aExtension;            /* Array of shared library handles */
   void (*xTrace)(void*,const char*);        /* Trace function */
@@ -940,7 +922,7 @@ struct sqlite3 {
 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
   int (*xProgress)(void *);     /* The progress callback */
   void *pProgressArg;           /* Argument to the progress callback */
-  int nProgressOps;             /* Number of opcodes for progress callback */
+  unsigned nProgressOps;        /* Number of opcodes for progress callback */
 #endif
 #ifndef SQLITE_OMIT_VIRTUALTABLE
   int nVTrans;                  /* Allocated size of aVTrans */
@@ -958,6 +940,7 @@ struct sqlite3 {
   int nSavepoint;               /* Number of non-transaction savepoints */
   int nStatement;               /* Number of nested statement-transactions  */
   i64 nDeferredCons;            /* Net deferred constraints this transaction. */
+  i64 nDeferredImmCons;         /* Net deferred immediate constraints */
   int *pnBytesFreed;            /* If not NULL, increment this in DbFree() */
 
 #ifdef SQLITE_ENABLE_UNLOCK_NOTIFY
@@ -989,30 +972,34 @@ struct sqlite3 {
 */
 #define SQLITE_VdbeTrace      0x00000001  /* True to trace VDBE execution */
 #define SQLITE_InternChanges  0x00000002  /* Uncommitted Hash table changes */
-#define SQLITE_FullColNames   0x00000004  /* Show full column names on SELECT */
-#define SQLITE_ShortColNames  0x00000008  /* Show short columns names */
-#define SQLITE_CountRows      0x00000010  /* Count rows changed by INSERT, */
+#define SQLITE_FullFSync      0x00000004  /* Use full fsync on the backend */
+#define SQLITE_CkptFullFSync  0x00000008  /* Use full fsync for checkpoint */
+#define SQLITE_CacheSpill     0x00000010  /* OK to spill pager cache */
+#define SQLITE_FullColNames   0x00000020  /* Show full column names on SELECT */
+#define SQLITE_ShortColNames  0x00000040  /* Show short columns names */
+#define SQLITE_CountRows      0x00000080  /* Count rows changed by INSERT, */
                                           /*   DELETE, or UPDATE and return */
                                           /*   the count using a callback. */
-#define SQLITE_NullCallback   0x00000020  /* Invoke the callback once if the */
+#define SQLITE_NullCallback   0x00000100  /* Invoke the callback once if the */
                                           /*   result set is empty */
-#define SQLITE_SqlTrace       0x00000040  /* Debug print SQL as it executes */
-#define SQLITE_VdbeListing    0x00000080  /* Debug listings of VDBE programs */
-#define SQLITE_WriteSchema    0x00000100  /* OK to update SQLITE_MASTER */
-#define SQLITE_VdbeAddopTrace 0x00000200  /* Trace sqlite3VdbeAddOp() calls */
-#define SQLITE_IgnoreChecks   0x00000400  /* Do not enforce check constraints */
-#define SQLITE_ReadUncommitted 0x0000800  /* For shared-cache mode */
-#define SQLITE_LegacyFileFmt  0x00001000  /* Create new databases in format 1 */
-#define SQLITE_FullFSync      0x00002000  /* Use full fsync on the backend */
-#define SQLITE_CkptFullFSync  0x00004000  /* Use full fsync for checkpoint */
-#define SQLITE_RecoveryMode   0x00008000  /* Ignore schema errors */
-#define SQLITE_ReverseOrder   0x00010000  /* Reverse unordered SELECTs */
-#define SQLITE_RecTriggers    0x00020000  /* Enable recursive triggers */
-#define SQLITE_ForeignKeys    0x00040000  /* Enforce foreign key constraints  */
-#define SQLITE_AutoIndex      0x00080000  /* Enable automatic indexes */
-#define SQLITE_PreferBuiltin  0x00100000  /* Preference to built-in funcs */
-#define SQLITE_LoadExtension  0x00200000  /* Enable load_extension */
-#define SQLITE_EnableTrigger  0x00400000  /* True to enable triggers */
+#define SQLITE_SqlTrace       0x00000200  /* Debug print SQL as it executes */
+#define SQLITE_VdbeListing    0x00000400  /* Debug listings of VDBE programs */
+#define SQLITE_WriteSchema    0x00000800  /* OK to update SQLITE_MASTER */
+#define SQLITE_VdbeAddopTrace 0x00001000  /* Trace sqlite3VdbeAddOp() calls */
+#define SQLITE_IgnoreChecks   0x00002000  /* Do not enforce check constraints */
+#define SQLITE_ReadUncommitted 0x0004000  /* For shared-cache mode */
+#define SQLITE_LegacyFileFmt  0x00008000  /* Create new databases in format 1 */
+#define SQLITE_RecoveryMode   0x00010000  /* Ignore schema errors */
+#define SQLITE_ReverseOrder   0x00020000  /* Reverse unordered SELECTs */
+#define SQLITE_RecTriggers    0x00040000  /* Enable recursive triggers */
+#define SQLITE_ForeignKeys    0x00080000  /* Enforce foreign key constraints  */
+#define SQLITE_AutoIndex      0x00100000  /* Enable automatic indexes */
+#define SQLITE_PreferBuiltin  0x00200000  /* Preference to built-in funcs */
+#define SQLITE_LoadExtension  0x00400000  /* Enable load_extension */
+#define SQLITE_EnableTrigger  0x00800000  /* True to enable triggers */
+#define SQLITE_DeferFKs       0x01000000  /* Defer all FK constraints */
+#define SQLITE_QueryOnly      0x02000000  /* Disable database changes */
+
 
 /*
 ** Bits of the sqlite3.dbOptFlags field that are used by the
@@ -1029,6 +1016,8 @@ struct sqlite3 {
 #define SQLITE_OrderByIdxJoin 0x0080   /* ORDER BY of joins via index */
 #define SQLITE_SubqCoroutine  0x0100   /* Evaluate subqueries as coroutines */
 #define SQLITE_Transitive     0x0200   /* Transitive constraints */
+#define SQLITE_OmitNoopJoin   0x0400   /* Omit unused tables in joins */
+#define SQLITE_Stat3          0x0800   /* Use the SQLITE_STAT3 table */
 #define SQLITE_AllOpts        0xffff   /* All optimizations */
 
 /*
@@ -1157,6 +1146,7 @@ struct FuncDestructor {
 struct Savepoint {
   char *zName;                        /* Savepoint name (nul-terminated) */
   i64 nDeferredCons;                  /* Number of deferred fk violations */
+  i64 nDeferredImmCons;               /* Number of deferred imm fk. */
   Savepoint *pNext;                   /* Parent savepoint (if any) */
 };
 
@@ -1475,12 +1465,16 @@ struct FKey {
 ** An instance of the following structure is passed as the first
 ** argument to sqlite3VdbeKeyCompare and is used to control the 
 ** comparison of the two index keys.
+**
+** Note that aSortOrder[] and aColl[] have nField+1 slots.  There
+** are nField slots for the columns of an index then one extra slot
+** for the rowid at the end.
 */
 struct KeyInfo {
   sqlite3 *db;        /* The database connection */
   u8 enc;             /* Text encoding - one of the SQLITE_UTF* values */
-  u16 nField;         /* Number of entries in aColl[] */
-  u8 *aSortOrder;     /* Sort order for each column.  May be NULL */
+  u16 nField;         /* Maximum index for aColl[] and aSortOrder[] */
+  u8 *aSortOrder;     /* Sort order for each column. */
   CollSeq *aColl[1];  /* Collating sequence for each term of the key */
 };
 
@@ -1549,11 +1543,13 @@ struct Index {
   Schema *pSchema;         /* Schema containing this index */
   u8 *aSortOrder;          /* for each column: True==DESC, False==ASC */
   char **azColl;           /* Array of collation sequence names for index */
+  Expr *pPartIdxWhere;     /* WHERE clause for partial indices */
   int tnum;                /* DB Page containing root of this index */
   u16 nColumn;             /* Number of columns in table used by this index */
   u8 onError;              /* OE_Abort, OE_Ignore, OE_Replace, or OE_None */
   unsigned autoIndex:2;    /* 1==UNIQUE, 2==PRIMARY KEY, 0==CREATE INDEX */
   unsigned bUnordered:1;   /* Use this index for == or IN queries only */
+  unsigned uniqNotNull:1;  /* True if UNIQUE and NOT NULL for all columns */
 #ifdef SQLITE_ENABLE_STAT3
   int nSample;             /* Number of elements in aSample[] */
   tRowcnt avgEq;           /* Average nEq value for key values not in aSample */
@@ -1900,6 +1896,11 @@ typedef u64 Bitmask;
 #define BMS  ((int)(sizeof(Bitmask)*8))
 
 /*
+** A bit in a Bitmask
+*/
+#define MASKBIT(n)   (((Bitmask)1)<<(n))
+
+/*
 ** The following structure describes the FROM clause of a SELECT statement.
 ** Each table or subquery in the FROM clause is a separate element of
 ** the SrcList.a[] array.
@@ -1919,8 +1920,8 @@ typedef u64 Bitmask;
 ** contains more than 63 columns and the 64-th or later column is used.
 */
 struct SrcList {
-  i16 nSrc;        /* Number of tables or subqueries in the FROM clause */
-  i16 nAlloc;      /* Number of entries allocated in a[] below */
+  u8 nSrc;        /* Number of tables or subqueries in the FROM clause */
+  u8 nAlloc;      /* Number of entries allocated in a[] below */
   struct SrcList_item {
     Schema *pSchema;  /* Schema to which this item is fixed */
     char *zDatabase;  /* Name of database holding this table */
@@ -1959,79 +1960,6 @@ struct SrcList {
 
 
 /*
-** A WherePlan object holds information that describes a lookup
-** strategy.
-**
-** This object is intended to be opaque outside of the where.c module.
-** It is included here only so that that compiler will know how big it
-** is.  None of the fields in this object should be used outside of
-** the where.c module.
-**
-** Within the union, pIdx is only used when wsFlags&WHERE_INDEXED is true.
-** pTerm is only used when wsFlags&WHERE_MULTI_OR is true.  And pVtabIdx
-** is only used when wsFlags&WHERE_VIRTUALTABLE is true.  It is never the
-** case that more than one of these conditions is true.
-*/
-struct WherePlan {
-  u32 wsFlags;                   /* WHERE_* flags that describe the strategy */
-  u16 nEq;                       /* Number of == constraints */
-  u16 nOBSat;                    /* Number of ORDER BY terms satisfied */
-  double nRow;                   /* Estimated number of rows (for EQP) */
-  union {
-    Index *pIdx;                   /* Index when WHERE_INDEXED is true */
-    struct WhereTerm *pTerm;       /* WHERE clause term for OR-search */
-    sqlite3_index_info *pVtabIdx;  /* Virtual table index to use */
-  } u;
-};
-
-/*
-** For each nested loop in a WHERE clause implementation, the WhereInfo
-** structure contains a single instance of this structure.  This structure
-** is intended to be private to the where.c module and should not be
-** access or modified by other modules.
-**
-** The pIdxInfo field is used to help pick the best index on a
-** virtual table.  The pIdxInfo pointer contains indexing
-** information for the i-th table in the FROM clause before reordering.
-** All the pIdxInfo pointers are freed by whereInfoFree() in where.c.
-** All other information in the i-th WhereLevel object for the i-th table
-** after FROM clause ordering.
-*/
-struct WhereLevel {
-  WherePlan plan;       /* query plan for this element of the FROM clause */
-  int iLeftJoin;        /* Memory cell used to implement LEFT OUTER JOIN */
-  int iTabCur;          /* The VDBE cursor used to access the table */
-  int iIdxCur;          /* The VDBE cursor used to access pIdx */
-  int addrBrk;          /* Jump here to break out of the loop */
-  int addrNxt;          /* Jump here to start the next IN combination */
-  int addrCont;         /* Jump here to continue with the next loop cycle */
-  int addrFirst;        /* First instruction of interior of the loop */
-  u8 iFrom;             /* Which entry in the FROM clause */
-  u8 op, p5;            /* Opcode and P5 of the opcode that ends the loop */
-  int p1, p2;           /* Operands of the opcode used to ends the loop */
-  union {               /* Information that depends on plan.wsFlags */
-    struct {
-      int nIn;              /* Number of entries in aInLoop[] */
-      struct InLoop {
-        int iCur;              /* The VDBE cursor used by this IN operator */
-        int addrInTop;         /* Top of the IN loop */
-        u8 eEndLoopOp;         /* IN Loop terminator. OP_Next or OP_Prev */
-      } *aInLoop;           /* Information about each nested IN operator */
-    } in;                 /* Used when plan.wsFlags&WHERE_IN_ABLE */
-    Index *pCovidx;       /* Possible covering index for WHERE_MULTI_OR */
-  } u;
-  double rOptCost;      /* "Optimal" cost for this level */
-
-  /* The following field is really not part of the current level.  But
-  ** we need a place to cache virtual table index information for each
-  ** virtual table in the FROM clause and the WhereLevel structure is
-  ** a convenient place since there is one WhereLevel for each FROM clause
-  ** element.
-  */
-  sqlite3_index_info *pIdxInfo;  /* Index info for n-th source table */
-};
-
-/*
 ** Flags appropriate for the wctrlFlags parameter of sqlite3WhereBegin()
 ** and the WhereInfo.wctrlFlags member.
 */
@@ -2044,33 +1972,12 @@ struct WhereLevel {
 #define WHERE_FORCE_TABLE      0x0020 /* Do not use an index-only search */
 #define WHERE_ONETABLE_ONLY    0x0040 /* Only code the 1st table in pTabList */
 #define WHERE_AND_ONLY         0x0080 /* Don't use indices for OR terms */
+#define WHERE_GROUPBY          0x0100 /* pOrderBy is really a GROUP BY */
+#define WHERE_DISTINCTBY       0x0200 /* pOrderby is really a DISTINCT clause */
+#define WHERE_WANT_DISTINCT    0x0400 /* All output needs to be distinct */
 
-/*
-** The WHERE clause processing routine has two halves.  The
-** first part does the start of the WHERE loop and the second
-** half does the tail of the WHERE loop.  An instance of
-** this structure is returned by the first half and passed
-** into the second half to give some continuity.
-*/
-struct WhereInfo {
-  Parse *pParse;            /* Parsing and code generating context */
-  SrcList *pTabList;        /* List of tables in the join */
-  u16 nOBSat;               /* Number of ORDER BY terms satisfied by indices */
-  u16 wctrlFlags;           /* Flags originally passed to sqlite3WhereBegin() */
-  u8 okOnePass;             /* Ok to use one-pass algorithm for UPDATE/DELETE */
-  u8 untestedTerms;         /* Not all WHERE terms resolved by outer loop */
-  u8 eDistinct;             /* One of the WHERE_DISTINCT_* values below */
-  int iTop;                 /* The very beginning of the WHERE loop */
-  int iContinue;            /* Jump here to continue with next record */
-  int iBreak;               /* Jump here to break out of the loop */
-  int nLevel;               /* Number of nested loop */
-  struct WhereClause *pWC;  /* Decomposition of the WHERE clause */
-  double savedNQueryLoop;   /* pParse->nQueryLoop outside the WHERE loop */
-  double nRowOut;           /* Estimated number of output rows */
-  WhereLevel a[1];          /* Information about each nest loop in WHERE */
-};
-
-/* Allowed values for WhereInfo.eDistinct and DistinctCtx.eTnctType */
+/* Allowed return values from sqlite3WhereIsDistinct()
+*/
 #define WHERE_DISTINCT_NOOP      0  /* DISTINCT keyword not used */
 #define WHERE_DISTINCT_UNIQUE    1  /* No duplicates */
 #define WHERE_DISTINCT_ORDERED   2  /* All duplicates are adjacent */
@@ -2100,7 +2007,7 @@ struct WhereInfo {
 struct NameContext {
   Parse *pParse;       /* The parser */
   SrcList *pSrcList;   /* One or more tables used to resolve names */
-  ExprList *pEList;    /* Optional list of named expressions */
+  ExprList *pEList;    /* Optional list of result-set columns */
   AggInfo *pAggInfo;   /* Information about aggregates at this level */
   NameContext *pNext;  /* Next outer name context.  NULL for outermost */
   int nRef;            /* Number of names resolved by this context */
@@ -2115,8 +2022,7 @@ struct NameContext {
 #define NC_HasAgg    0x02    /* One or more aggregate functions seen */
 #define NC_IsCheck   0x04    /* True if resolving names in a CHECK constraint */
 #define NC_InAggFunc 0x08    /* True if analyzing arguments to an agg func */
-#define NC_AsMaybe   0x10    /* Resolve to AS terms of the result set only
-                             ** if no other resolution is available */
+#define NC_PartIdx   0x10    /* True if resolving a partial index WHERE */
 
 /*
 ** An instance of the following structure contains all information
@@ -2144,7 +2050,7 @@ struct Select {
   u16 selFlags;          /* Various SF_* values */
   int iLimit, iOffset;   /* Memory registers holding LIMIT & OFFSET counters */
   int addrOpenEphm[3];   /* OP_OpenEphem opcodes related to this select */
-  double nSelectRow;     /* Estimated number of result rows */
+  u64 nSelectRow;        /* Estimated number of result rows */
   SrcList *pSrc;         /* The FROM clause */
   Expr *pWhere;          /* The WHERE clause */
   ExprList *pGroupBy;    /* The GROUP BY clause */
@@ -2171,6 +2077,7 @@ struct Select {
 #define SF_Values          0x0080  /* Synthesized from VALUES clause */
 #define SF_Materialize     0x0100  /* Force materialization of views */
 #define SF_NestedFrom      0x0200  /* Part of a parenthesized FROM clause */
+#define SF_MaybeConvert    0x0400  /* Need convertCompoundSelectToSubquery() */
 
 
 /*
@@ -2292,6 +2199,7 @@ struct Parse {
   u8 iColCache;        /* Next entry in aColCache[] to replace */
   u8 isMultiWrite;     /* True if statement may modify/insert multiple rows */
   u8 mayAbort;         /* True if statement may throw an ABORT exception */
+  u8 hasCompound;      /* Need to invoke convertCompoundSelectToSubquery() */
   int aTempReg[8];     /* Holding area for temporary registers */
   int nRangeReg;       /* Size of the temporary register block */
   int iRangeReg;       /* First register in temporary register block */
@@ -2301,6 +2209,7 @@ struct Parse {
   int nSet;            /* Number of sets used so far */
   int nOnce;           /* Number of OP_Once instructions so far */
   int ckBase;          /* Base register of data during check constraints */
+  int iPartIdxTab;     /* Table corresponding to a partial index */
   int iCacheLevel;     /* ColCache valid when aColCache[].iLevel<=iCacheLevel */
   int iCacheCnt;       /* Counter used to generate aColCache[].lru values */
   struct yColCache {
@@ -2328,7 +2237,7 @@ struct Parse {
   /* Information used while coding trigger programs. */
   Parse *pToplevel;    /* Parse structure for main program (or NULL) */
   Table *pTriggerTab;  /* Table triggers are being coded for */
-  double nQueryLoop;   /* Estimated number of iterations of a query */
+  u32 nQueryLoop;      /* Est number of iterations of a query (10*log2(N)) */
   u32 oldmask;         /* Mask of old.* columns referenced */
   u32 newmask;         /* Mask of new.* columns referenced */
   u8 eTriggerOp;       /* TK_UPDATE, TK_INSERT or TK_DELETE */
@@ -2516,10 +2425,11 @@ struct StrAccum {
   int  nChar;          /* Length of the string so far */
   int  nAlloc;         /* Amount of space allocated in zText */
   int  mxAlloc;        /* Maximum allowed string length */
-  u8   mallocFailed;   /* Becomes true if any memory allocation fails */
   u8   useMalloc;      /* 0: none,  1: sqlite3DbMalloc,  2: sqlite3_malloc */
-  u8   tooBig;         /* Becomes true if string size exceeds limits */
+  u8   accError;       /* STRACCUM_NOMEM or STRACCUM_TOOBIG */
 };
+#define STRACCUM_NOMEM   1
+#define STRACCUM_TOOBIG  2
 
 /*
 ** A pointer to this structure is used to communicate information
@@ -2882,7 +2792,7 @@ void sqlite3SrcListAssignCursors(Parse*, SrcList*);
 void sqlite3IdListDelete(sqlite3*, IdList*);
 void sqlite3SrcListDelete(sqlite3*, SrcList*);
 Index *sqlite3CreateIndex(Parse*,Token*,Token*,SrcList*,ExprList*,int,Token*,
-                        Token*, int, int);
+                          Expr*, int, int);
 void sqlite3DropIndex(Parse*, SrcList*, int);
 int sqlite3Select(Parse*, Select*, SelectDest*);
 Select *sqlite3SelectNew(Parse*,ExprList*,SrcList*,Expr*,ExprList*,
@@ -2898,6 +2808,12 @@ void sqlite3DeleteFrom(Parse*, SrcList*, Expr*);
 void sqlite3Update(Parse*, SrcList*, ExprList*, Expr*, int);
 WhereInfo *sqlite3WhereBegin(Parse*,SrcList*,Expr*,ExprList*,ExprList*,u16,int);
 void sqlite3WhereEnd(WhereInfo*);
+u64 sqlite3WhereOutputRowCount(WhereInfo*);
+int sqlite3WhereIsDistinct(WhereInfo*);
+int sqlite3WhereIsOrdered(WhereInfo*);
+int sqlite3WhereContinueLabel(WhereInfo*);
+int sqlite3WhereBreakLabel(WhereInfo*);
+int sqlite3WhereOkOnePass(WhereInfo*);
 int sqlite3ExprCodeGetColumn(Parse*, Table*, int, int, int, u8);
 void sqlite3ExprCodeGetColumnOfTable(Vdbe*, Table*, int, int, int);
 void sqlite3ExprCodeMove(Parse*, int, int, int);
@@ -2924,8 +2840,9 @@ void sqlite3UnlinkAndDeleteIndex(sqlite3*,int,const char*);
 void sqlite3Vacuum(Parse*);
 int sqlite3RunVacuum(char**, sqlite3*);
 char *sqlite3NameFromToken(sqlite3*, Token*);
-int sqlite3ExprCompare(Expr*, Expr*);
-int sqlite3ExprListCompare(ExprList*, ExprList*);
+int sqlite3ExprCompare(Expr*, Expr*, int);
+int sqlite3ExprListCompare(ExprList*, ExprList*, int);
+int sqlite3ExprImpliesExpr(Expr*, Expr*, int);
 void sqlite3ExprAnalyzeAggregates(NameContext*, Expr*);
 void sqlite3ExprAnalyzeAggList(NameContext*,ExprList*);
 int sqlite3FunctionUsesThisSrc(Expr*, SrcList*);
@@ -2952,7 +2869,7 @@ int sqlite3ExprNeedsNoAffinityChange(const Expr*, char);
 int sqlite3IsRowid(const char*);
 void sqlite3GenerateRowDelete(Parse*, Table*, int, int, int, Trigger *, int);
 void sqlite3GenerateRowIndexDelete(Parse*, Table*, int, int*);
-int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int);
+int sqlite3GenerateIndexKey(Parse*, Index*, int, int, int, int*);
 void sqlite3GenerateConstraintChecks(Parse*,Table*,int,int,
                                      int*,int,int,int,int,int*);
 void sqlite3CompleteInsertion(Parse*, Table*, int, int, int*, int, int, int);
@@ -3155,6 +3072,7 @@ void sqlite3SelectPrep(Parse*, Select*, NameContext*);
 int sqlite3MatchSpanName(const char*, const char*, const char*, const char*);
 int sqlite3ResolveExprNames(NameContext*, Expr*);
 void sqlite3ResolveSelectNames(Parse*, Select*, NameContext*);
+void sqlite3ResolveSelfReference(Parse*,Table*,int,Expr*,ExprList*);
 int sqlite3ResolveOrderGroupBy(Parse*, Select*, ExprList*, const char*);
 void sqlite3ColumnDefault(Vdbe *, Table *, int, int);
 void sqlite3AlterFinishAddColumn(Parse *, Token *);
@@ -3174,6 +3092,7 @@ void sqlite3MinimumFileFormat(Parse*, int, int);
 void sqlite3SchemaClear(void *);
 Schema *sqlite3SchemaGet(sqlite3 *, Btree *);
 int sqlite3SchemaToIndex(sqlite3 *db, Schema *);
+KeyInfo *sqlite3KeyInfoAlloc(sqlite3*,int);
 KeyInfo *sqlite3IndexKeyinfo(Parse *, Index *);
 int sqlite3CreateFunc(sqlite3 *, const char *, int, int, void *, 
   void (*)(sqlite3_context*,int,sqlite3_value **),
@@ -3235,13 +3154,14 @@ void sqlite3AutoLoadExtensions(sqlite3*);
 #else
    void sqlite3VtabClear(sqlite3 *db, Table*);
    void sqlite3VtabDisconnect(sqlite3 *db, Table *p);
-   int sqlite3VtabSync(sqlite3 *db, char **);
+   int sqlite3VtabSync(sqlite3 *db, Vdbe*);
    int sqlite3VtabRollback(sqlite3 *db);
    int sqlite3VtabCommit(sqlite3 *db);
    void sqlite3VtabLock(VTable *);
    void sqlite3VtabUnlock(VTable *);
    void sqlite3VtabUnlockList(sqlite3*);
    int sqlite3VtabSavepoint(sqlite3 *, int, int);
+   void sqlite3VtabImportErrmsg(Vdbe*, sqlite3_vtab*);
    VTable *sqlite3GetVTable(sqlite3*, Table*);
 #  define sqlite3VtabInSync(db) ((db)->nVTrans>0 && (db)->aVTrans==0)
 #endif
diff --git a/lib/libsqlite3/src/status.c b/lib/libsqlite3/src/status.c
index 28349e6d3d2..5fcb68ddc38 100644
--- a/lib/libsqlite3/src/status.c
+++ b/lib/libsqlite3/src/status.c
@@ -243,6 +243,16 @@ int sqlite3_db_status(
       break;
     }
 
+    /* Set *pCurrent to non-zero if there are unresolved deferred foreign
+    ** key constraints.  Set *pCurrent to zero if all foreign key constraints
+    ** have been satisfied.  The *pHighwater is always set to zero.
+    */
+    case SQLITE_DBSTATUS_DEFERRED_FKS: {
+      *pHighwater = 0;
+      *pCurrent = db->nDeferredImmCons>0 || db->nDeferredCons>0;
+      break;
+    }
+
     default: {
       rc = SQLITE_ERROR;
     }
diff --git a/lib/libsqlite3/src/tclsqlite.c b/lib/libsqlite3/src/tclsqlite.c
index f1bb2921da0..42f7bcdc3af 100644
--- a/lib/libsqlite3/src/tclsqlite.c
+++ b/lib/libsqlite3/src/tclsqlite.c
@@ -41,6 +41,18 @@
 #endif
 #include <ctype.h>
 
+/* Used to get the current process ID */
+#if !defined(_WIN32)
+# include <unistd.h>
+# define GETPID getpid
+#elif !defined(_WIN32_WCE)
+# ifndef SQLITE_AMALGAMATION
+#  define WIN32_LEAN_AND_MEAN
+#  include <windows.h>
+# endif
+# define GETPID (int)GetCurrentProcessId
+#endif
+
 /*
  * Windows needs to know which symbols to export.  Unix does not.
  * BUILD_sqlite should be undefined for Unix.
@@ -3050,7 +3062,7 @@ static int DbMain(void *cd, Tcl_Interp *interp, int objc,Tcl_Obj *const*objv){
 */
 #ifndef USE_TCL_STUBS
 # undef  Tcl_InitStubs
-# define Tcl_InitStubs(a,b,c)
+# define Tcl_InitStubs(a,b,c) TCL_VERSION
 #endif
 
 /*
@@ -3074,19 +3086,18 @@ static int DbMain(void *cd, Tcl_Interp *interp, int objc,Tcl_Obj *const*objv){
 ** The EXTERN macros are required by TCL in order to work on windows.
 */
 EXTERN int Sqlite3_Init(Tcl_Interp *interp){
-  Tcl_InitStubs(interp, "8.4", 0);
-  Tcl_CreateObjCommand(interp, "sqlite3", (Tcl_ObjCmdProc*)DbMain, 0, 0);
-  Tcl_PkgProvide(interp, "sqlite3", PACKAGE_VERSION);
-
+  int rc = Tcl_InitStubs(interp, "8.4", 0)==0 ? TCL_ERROR : TCL_OK;
+  if( rc==TCL_OK ){
+    Tcl_CreateObjCommand(interp, "sqlite3", (Tcl_ObjCmdProc*)DbMain, 0, 0);
 #ifndef SQLITE_3_SUFFIX_ONLY
-  /* The "sqlite" alias is undocumented.  It is here only to support
-  ** legacy scripts.  All new scripts should use only the "sqlite3"
-  ** command.
-  */
-  Tcl_CreateObjCommand(interp, "sqlite", (Tcl_ObjCmdProc*)DbMain, 0, 0);
+    /* The "sqlite" alias is undocumented.  It is here only to support
+    ** legacy scripts.  All new scripts should use only the "sqlite3"
+    ** command. */
+    Tcl_CreateObjCommand(interp, "sqlite", (Tcl_ObjCmdProc*)DbMain, 0, 0);
 #endif
-
-  return TCL_OK;
+    rc = Tcl_PkgProvide(interp, "sqlite3", PACKAGE_VERSION);
+  }
+  return rc;
 }
 EXTERN int Tclsqlite3_Init(Tcl_Interp *interp){ return Sqlite3_Init(interp); }
 EXTERN int Sqlite3_Unload(Tcl_Interp *interp, int flags){ return TCL_OK; }
@@ -3747,7 +3758,16 @@ static void init_all(Tcl_Interp *interp){
 #define TCLSH_MAIN main   /* Needed to fake out mktclapp */
 int TCLSH_MAIN(int argc, char **argv){
   Tcl_Interp *interp;
-  
+
+#if !defined(_WIN32_WCE)
+  if( getenv("BREAK") ){
+    fprintf(stderr,
+        "attach debugger to process %d and press any key to continue.\n",
+        GETPID());
+    fgetc(stdin);
+  }
+#endif
+
   /* Call sqlite3_shutdown() once before doing anything else. This is to
   ** test that sqlite3_shutdown() can be safely called by a process before
   ** sqlite3_initialize() is. */
diff --git a/lib/libsqlite3/src/test1.c b/lib/libsqlite3/src/test1.c
index a638e480add..9c38b11a6db 100644
--- a/lib/libsqlite3/src/test1.c
+++ b/lib/libsqlite3/src/test1.c
@@ -2218,6 +2218,7 @@ static int test_stmt_status(
     { "SQLITE_STMTSTATUS_FULLSCAN_STEP",   SQLITE_STMTSTATUS_FULLSCAN_STEP   },
     { "SQLITE_STMTSTATUS_SORT",            SQLITE_STMTSTATUS_SORT            },
     { "SQLITE_STMTSTATUS_AUTOINDEX",       SQLITE_STMTSTATUS_AUTOINDEX       },
+    { "SQLITE_STMTSTATUS_VM_STEP",         SQLITE_STMTSTATUS_VM_STEP         },
   };
   if( objc!=4 ){
     Tcl_WrongNumArgs(interp, 1, objv, "STMT PARAMETER RESETFLAG");
@@ -2469,7 +2470,7 @@ static int sqlite_static_bind_nbyte = 0;
 /*
 ** Usage:  sqlite3_bind  VM  IDX  VALUE  FLAGS
 **
-** Sets the value of the IDX-th occurance of "?" in the original SQL
+** Sets the value of the IDX-th occurrence of "?" in the original SQL
 ** string.  VALUE is the new value.  If FLAGS=="null" then VALUE is
 ** ignored and the value is set to NULL.  If FLAGS=="static" then
 ** the value is set to the value of a static variable named
@@ -5563,7 +5564,7 @@ static int test_wal_checkpoint(
 **
 ** Otherwise, this command returns a list of three integers. The first integer
 ** is 1 if SQLITE_BUSY was returned, or 0 otherwise. The following two integers
-** are the values returned via the output paramaters by wal_checkpoint_v2() -
+** are the values returned via the output parameters by wal_checkpoint_v2() -
 ** the number of frames in the log and the number of frames in the log
 ** that have been checkpointed.
 */
@@ -5958,15 +5959,20 @@ static int optimization_control(
     const char *zOptName;
     int mask;
   } aOpt[] = {
-    { "all",              SQLITE_AllOpts        },
-    { "query-flattener",  SQLITE_QueryFlattener },
-    { "column-cache",     SQLITE_ColumnCache    },
-    { "groupby-order",    SQLITE_GroupByOrder   },
-    { "factor-constants", SQLITE_FactorOutConst },
-    { "real-as-int",      SQLITE_IdxRealAsInt   },
-    { "distinct-opt",     SQLITE_DistinctOpt    },
-    { "cover-idx-scan",   SQLITE_CoverIdxScan   },
-    { "order-by-idx-join",SQLITE_OrderByIdxJoin },
+    { "all",                 SQLITE_AllOpts        },
+    { "none",                0                     },
+    { "query-flattener",     SQLITE_QueryFlattener },
+    { "column-cache",        SQLITE_ColumnCache    },
+    { "groupby-order",       SQLITE_GroupByOrder   },
+    { "factor-constants",    SQLITE_FactorOutConst },
+    { "real-as-int",         SQLITE_IdxRealAsInt   },
+    { "distinct-opt",        SQLITE_DistinctOpt    },
+    { "cover-idx-scan",      SQLITE_CoverIdxScan   },
+    { "order-by-idx-join",   SQLITE_OrderByIdxJoin },
+    { "transitive",          SQLITE_Transitive     },
+    { "subquery-coroutine",  SQLITE_SubqCoroutine  },
+    { "omit-noop-join",      SQLITE_OmitNoopJoin   },
+    { "stat3",               SQLITE_Stat3          },
   };
 
   if( objc!=4 ){
@@ -5987,7 +5993,7 @@ static int optimization_control(
     Tcl_AppendResult(interp, "unknown optimization - should be one of:",
                      (char*)0);
     for(i=0; i<sizeof(aOpt)/sizeof(aOpt[0]); i++){
-      Tcl_AppendResult(interp, " ", aOpt[i].zOptName);
+      Tcl_AppendResult(interp, " ", aOpt[i].zOptName, (char*)0);
     }
     return TCL_ERROR;
   }
@@ -6012,6 +6018,7 @@ static int tclLoadStaticExtensionCmd(
   extern int sqlite3_fuzzer_init(sqlite3*,char**,const sqlite3_api_routines*);
   extern int sqlite3_ieee_init(sqlite3*,char**,const sqlite3_api_routines*);
   extern int sqlite3_nextchar_init(sqlite3*,char**,const sqlite3_api_routines*);
+  extern int sqlite3_percentile_init(sqlite3*,char**,const sqlite3_api_routines*);
   extern int sqlite3_regexp_init(sqlite3*,char**,const sqlite3_api_routines*);
   extern int sqlite3_spellfix_init(sqlite3*,char**,const sqlite3_api_routines*);
   extern int sqlite3_wholenumber_init(sqlite3*,char**,const sqlite3_api_routines*);
@@ -6024,6 +6031,7 @@ static int tclLoadStaticExtensionCmd(
     { "fuzzer",                sqlite3_fuzzer_init               },
     { "ieee754",               sqlite3_ieee_init                 },
     { "nextchar",              sqlite3_nextchar_init             },
+    { "percentile",            sqlite3_percentile_init           },
     { "regexp",                sqlite3_regexp_init               },
     { "spellfix",              sqlite3_spellfix_init             },
     { "wholenumber",           sqlite3_wholenumber_init          },
@@ -6300,8 +6308,6 @@ int Sqlitetest1_Init(Tcl_Interp *interp){
   extern int sqlite3WalTrace;
 #endif
 #ifdef SQLITE_TEST
-  extern char sqlite3_query_plan[];
-  static char *query_plan = sqlite3_query_plan;
 #ifdef SQLITE_ENABLE_FTS3
   extern int sqlite3_fts3_enable_parentheses;
 #endif
@@ -6355,8 +6361,11 @@ int Sqlitetest1_Init(Tcl_Interp *interp){
       (char*)&sqlite3_os_type, TCL_LINK_INT);
 #endif
 #ifdef SQLITE_TEST
-  Tcl_LinkVar(interp, "sqlite_query_plan",
-      (char*)&query_plan, TCL_LINK_STRING|TCL_LINK_READ_ONLY);
+  {
+    static const char *query_plan = "*** OBSOLETE VARIABLE ***";
+    Tcl_LinkVar(interp, "sqlite_query_plan",
+       (char*)&query_plan, TCL_LINK_STRING|TCL_LINK_READ_ONLY);
+  }
 #endif
 #ifdef SQLITE_DEBUG
   Tcl_LinkVar(interp, "sqlite_where_trace",
diff --git a/lib/libsqlite3/src/test_autoext.c b/lib/libsqlite3/src/test_autoext.c
index b5013f3173a..a5236d23908 100644
--- a/lib/libsqlite3/src/test_autoext.c
+++ b/lib/libsqlite3/src/test_autoext.c
@@ -99,6 +99,22 @@ static int autoExtSqrObjCmd(
 }
 
 /*
+** tclcmd:   sqlite3_cancel_auto_extension_sqr
+**
+** Unregister the "sqr" extension.
+*/
+static int cancelAutoExtSqrObjCmd(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int rc = sqlite3_cancel_auto_extension((void*)sqr_init);
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(rc));
+  return SQLITE_OK;
+}
+
+/*
 ** tclcmd:   sqlite3_auto_extension_cube
 **
 ** Register the "cube" extension to be loaded automatically.
@@ -115,6 +131,22 @@ static int autoExtCubeObjCmd(
 }
 
 /*
+** tclcmd:   sqlite3_cancel_auto_extension_cube
+**
+** Unregister the "cube" extension.
+*/
+static int cancelAutoExtCubeObjCmd(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int rc = sqlite3_cancel_auto_extension((void*)cube_init);
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(rc));
+  return SQLITE_OK;
+}
+
+/*
 ** tclcmd:   sqlite3_auto_extension_broken
 **
 ** Register the broken extension to be loaded automatically.
@@ -130,6 +162,22 @@ static int autoExtBrokenObjCmd(
   return SQLITE_OK;
 }
 
+/*
+** tclcmd:   sqlite3_cancel_auto_extension_broken
+**
+** Unregister the broken extension.
+*/
+static int cancelAutoExtBrokenObjCmd(
+  void * clientData,
+  Tcl_Interp *interp,
+  int objc,
+  Tcl_Obj *CONST objv[]
+){
+  int rc = sqlite3_cancel_auto_extension((void*)broken_init);
+  Tcl_SetObjResult(interp, Tcl_NewIntObj(rc));
+  return SQLITE_OK;
+}
+
 #endif /* SQLITE_OMIT_LOAD_EXTENSION */
 
 
@@ -160,6 +208,12 @@ int Sqlitetest_autoext_Init(Tcl_Interp *interp){
           autoExtCubeObjCmd, 0, 0);
   Tcl_CreateObjCommand(interp, "sqlite3_auto_extension_broken",
           autoExtBrokenObjCmd, 0, 0);
+  Tcl_CreateObjCommand(interp, "sqlite3_cancel_auto_extension_sqr",
+          cancelAutoExtSqrObjCmd, 0, 0);
+  Tcl_CreateObjCommand(interp, "sqlite3_cancel_auto_extension_cube",
+          cancelAutoExtCubeObjCmd, 0, 0);
+  Tcl_CreateObjCommand(interp, "sqlite3_cancel_auto_extension_broken",
+          cancelAutoExtBrokenObjCmd, 0, 0);
 #endif
   Tcl_CreateObjCommand(interp, "sqlite3_reset_auto_extension",
           resetAutoExtObjCmd, 0, 0);
diff --git a/lib/libsqlite3/src/test_demovfs.c b/lib/libsqlite3/src/test_demovfs.c
index 637627071d9..c63b0a8b7a1 100644
--- a/lib/libsqlite3/src/test_demovfs.c
+++ b/lib/libsqlite3/src/test_demovfs.c
@@ -536,7 +536,7 @@ static int demoFullPathname(
   if( zPath[0]=='/' ){
     zDir[0] = '\0';
   }else{
-    getcwd(zDir, sizeof(zDir));
+    if( getcwd(zDir, sizeof(zDir))==0 ) return SQLITE_IOERR;
   }
   zDir[MAXPATHNAME] = '\0';
 
diff --git a/lib/libsqlite3/src/test_fs.c b/lib/libsqlite3/src/test_fs.c
index 478cad80b16..417c81b49f2 100644
--- a/lib/libsqlite3/src/test_fs.c
+++ b/lib/libsqlite3/src/test_fs.c
@@ -195,6 +195,7 @@ static int fsColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
     const char *zFile = (const char *)sqlite3_column_text(pCur->pStmt, 1);
     struct stat sbuf;
     int fd;
+    int n;
 
     fd = open(zFile, O_RDONLY);
     if( fd<0 ) return SQLITE_IOERR;
@@ -214,8 +215,9 @@ static int fsColumn(sqlite3_vtab_cursor *cur, sqlite3_context *ctx, int i){
       pCur->nAlloc = nNew;
     }
 
-    read(fd, pCur->zBuf, sbuf.st_size);
+    n = (int)read(fd, pCur->zBuf, sbuf.st_size);
     close(fd);
+    if( n!=sbuf.st_size ) return SQLITE_ERROR;
     pCur->nBuf = sbuf.st_size;
     pCur->zBuf[pCur->nBuf] = '\0';
 
diff --git a/lib/libsqlite3/src/test_intarray.h b/lib/libsqlite3/src/test_intarray.h
index 691337d1aed..6d26235a870 100644
--- a/lib/libsqlite3/src/test_intarray.h
+++ b/lib/libsqlite3/src/test_intarray.h
@@ -75,6 +75,8 @@
 ** action to free the intarray objects.
 */
 #include "sqlite3.h"
+#ifndef _INTARRAY_H_
+#define _INTARRAY_H_
 
 /*
 ** Make sure we can call this stuff from C++.
@@ -123,3 +125,4 @@ int sqlite3_intarray_bind(
 #ifdef __cplusplus
 }  /* End of the 'extern "C"' block */
 #endif
+#endif /* _INTARRAY_H_ */
diff --git a/lib/libsqlite3/src/test_malloc.c b/lib/libsqlite3/src/test_malloc.c
index cf98a8fb218..2e31f0833d2 100644
--- a/lib/libsqlite3/src/test_malloc.c
+++ b/lib/libsqlite3/src/test_malloc.c
@@ -1349,7 +1349,8 @@ static int test_db_status(
     { "LOOKASIDE_MISS_FULL", SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL },
     { "CACHE_HIT",           SQLITE_DBSTATUS_CACHE_HIT           },
     { "CACHE_MISS",          SQLITE_DBSTATUS_CACHE_MISS          },
-    { "CACHE_WRITE",         SQLITE_DBSTATUS_CACHE_WRITE         }
+    { "CACHE_WRITE",         SQLITE_DBSTATUS_CACHE_WRITE         },
+    { "DEFERRED_FKS",        SQLITE_DBSTATUS_DEFERRED_FKS        }
   };
   Tcl_Obj *pResult;
   if( objc!=4 ){
diff --git a/lib/libsqlite3/src/test_multiplex.h b/lib/libsqlite3/src/test_multiplex.h
index b7e1afea5fd..9fe2f0f2b22 100644
--- a/lib/libsqlite3/src/test_multiplex.h
+++ b/lib/libsqlite3/src/test_multiplex.h
@@ -96,4 +96,4 @@ extern int sqlite3_multiplex_shutdown(void);
 }  /* End of the 'extern "C"' block */
 #endif
 
-#endif
+#endif /* _TEST_MULTIPLEX_H */
diff --git a/lib/libsqlite3/src/test_rtree.c b/lib/libsqlite3/src/test_rtree.c
index f54ae9b063b..e1966c24373 100644
--- a/lib/libsqlite3/src/test_rtree.c
+++ b/lib/libsqlite3/src/test_rtree.c
@@ -14,6 +14,7 @@
 */
 
 #include <sqlite3.h>
+#include <tcl.h>
 
 /* Solely for the UNUSED_PARAMETER() macro. */
 #include "sqliteInt.h"
diff --git a/lib/libsqlite3/src/test_schema.c b/lib/libsqlite3/src/test_schema.c
index 12644467647..00a9f4dd903 100644
--- a/lib/libsqlite3/src/test_schema.c
+++ b/lib/libsqlite3/src/test_schema.c
@@ -344,7 +344,10 @@ int Sqlitetestschema_Init(Tcl_Interp *interp){
 /*
 ** Extension load function.
 */
-int sqlite3_extension_init(
+#ifdef _WIN32
+__declspec(dllexport)
+#endif
+int sqlite3_schema_init(
   sqlite3 *db, 
   char **pzErrMsg, 
   const sqlite3_api_routines *pApi
diff --git a/lib/libsqlite3/src/test_vfs.c b/lib/libsqlite3/src/test_vfs.c
index fcd577439cf..613b0fce774 100644
--- a/lib/libsqlite3/src/test_vfs.c
+++ b/lib/libsqlite3/src/test_vfs.c
@@ -28,6 +28,7 @@
 
 #include "sqlite3.h"
 #include "sqliteInt.h"
+#include <tcl.h>
 
 typedef struct Testvfs Testvfs;
 typedef struct TestvfsShm TestvfsShm;
@@ -190,8 +191,11 @@ static int tvfsShmMap(sqlite3_file*,int,int,int, void volatile **);
 static void tvfsShmBarrier(sqlite3_file*);
 static int tvfsShmUnmap(sqlite3_file*, int);
 
+static int tvfsFetch(sqlite3_file*, sqlite3_int64, int, void**);
+static int tvfsUnfetch(sqlite3_file*, sqlite3_int64, void*);
+
 static sqlite3_io_methods tvfs_io_methods = {
-  2,                              /* iVersion */
+  3,                              /* iVersion */
   tvfsClose,                      /* xClose */
   tvfsRead,                       /* xRead */
   tvfsWrite,                      /* xWrite */
@@ -207,7 +211,9 @@ static sqlite3_io_methods tvfs_io_methods = {
   tvfsShmMap,                     /* xShmMap */
   tvfsShmLock,                    /* xShmLock */
   tvfsShmBarrier,                 /* xShmBarrier */
-  tvfsShmUnmap                    /* xShmUnmap */
+  tvfsShmUnmap,                   /* xShmUnmap */
+  tvfsFetch,
+  tvfsUnfetch
 };
 
 static int tvfsResultCode(Testvfs *p, int *pRc){
@@ -618,7 +624,10 @@ static int tvfsOpen(
 
     pMethods = (sqlite3_io_methods *)ckalloc(nByte);
     memcpy(pMethods, &tvfs_io_methods, nByte);
-    pMethods->iVersion = pVfs->iVersion;
+    pMethods->iVersion = pFd->pReal->pMethods->iVersion;
+    if( pMethods->iVersion>pVfs->iVersion ){
+      pMethods->iVersion = pVfs->iVersion;
+    }
     if( pVfs->iVersion>1 && ((Testvfs *)pVfs->pAppData)->isNoshm ){
       pMethods->xShmUnmap = 0;
       pMethods->xShmLock = 0;
@@ -993,6 +1002,21 @@ static int tvfsShmUnmap(
   return rc;
 }
 
+static int tvfsFetch(
+    sqlite3_file *pFile, 
+    sqlite3_int64 iOfst, 
+    int iAmt, 
+    void **pp
+){
+  TestvfsFd *pFd = tvfsGetFd(pFile);
+  return sqlite3OsFetch(pFd->pReal, iOfst, iAmt, pp);
+}
+
+static int tvfsUnfetch(sqlite3_file *pFile, sqlite3_int64 iOfst, void *p){
+  TestvfsFd *pFd = tvfsGetFd(pFile);
+  return sqlite3OsUnfetch(pFd->pReal, iOfst, p);
+}
+
 static int testvfs_obj_cmd(
   ClientData cd,
   Tcl_Interp *interp,
@@ -1343,7 +1367,7 @@ static int testvfs_cmd(
   Tcl_Obj *CONST objv[]
 ){
   static sqlite3_vfs tvfs_vfs = {
-    2,                            /* iVersion */
+    3,                            /* iVersion */
     0,                            /* szOsFile */
     0,                            /* mxPathname */
     0,                            /* pNext */
@@ -1369,6 +1393,9 @@ static int testvfs_cmd(
     tvfsCurrentTime,              /* xCurrentTime */
     0,                            /* xGetLastError */
     0,                            /* xCurrentTimeInt64 */
+    0,                            /* xSetSystemCall */
+    0,                            /* xGetSystemCall */
+    0,                            /* xNextSystemCall */
   };
 
   Testvfs *p;                     /* New object */
@@ -1382,7 +1409,7 @@ static int testvfs_cmd(
   int isDefault = 0;              /* True if -default is passed */
   int szOsFile = 0;               /* Value passed to -szosfile */
   int mxPathname = -1;            /* Value passed to -mxpathname */
-  int iVersion = 2;               /* Value passed to -iversion */
+  int iVersion = 3;               /* Value passed to -iversion */
 
   if( objc<2 || 0!=(objc%2) ) goto bad_args;
   for(i=2; i<objc; i += 2){
diff --git a/lib/libsqlite3/src/tokenize.c b/lib/libsqlite3/src/tokenize.c
index faea5f26c79..d26157f7d23 100644
--- a/lib/libsqlite3/src/tokenize.c
+++ b/lib/libsqlite3/src/tokenize.c
@@ -123,7 +123,6 @@ int sqlite3GetToken(const unsigned char *z, int *tokenType){
     }
     case '-': {
       if( z[1]=='-' ){
-        /* IMP: R-50417-27976 -- syntax diagram for comments */
         for(i=2; (c=z[i])!=0 && c!='\n'; i++){}
         *tokenType = TK_SPACE;   /* IMP: R-22934-25134 */
         return i;
@@ -156,7 +155,6 @@ int sqlite3GetToken(const unsigned char *z, int *tokenType){
         *tokenType = TK_SLASH;
         return 1;
       }
-      /* IMP: R-50417-27976 -- syntax diagram for comments */
       for(i=3, c=z[2]; (c!='*' || z[i]!='/') && (c=z[i])!=0; i++){}
       if( c ) i++;
       *tokenType = TK_SPACE;   /* IMP: R-22934-25134 */
@@ -396,7 +394,7 @@ int sqlite3RunParser(Parse *pParse, const char *zSql, char **pzErrMsg){
 
 
   mxSqlLen = db->aLimit[SQLITE_LIMIT_SQL_LENGTH];
-  if( db->activeVdbeCnt==0 ){
+  if( db->nVdbeActive==0 ){
     db->u1.isInterrupted = 0;
   }
   pParse->rc = SQLITE_OK;
diff --git a/lib/libsqlite3/src/trigger.c b/lib/libsqlite3/src/trigger.c
index f1ff766e202..b901d07678e 100644
--- a/lib/libsqlite3/src/trigger.c
+++ b/lib/libsqlite3/src/trigger.c
@@ -1002,7 +1002,7 @@ void sqlite3CodeRowTriggerDirect(
 /*
 ** This is called to code the required FOR EACH ROW triggers for an operation
 ** on table pTab. The operation to code triggers for (INSERT, UPDATE or DELETE)
-** is given by the op paramater. The tr_tm parameter determines whether the
+** is given by the op parameter. The tr_tm parameter determines whether the
 ** BEFORE or AFTER triggers are coded. If the operation is an UPDATE, then
 ** parameter pChanges is passed the list of columns being modified.
 **
diff --git a/lib/libsqlite3/src/update.c b/lib/libsqlite3/src/update.c
index 3ab1ab2a4b6..4fbefc3b595 100644
--- a/lib/libsqlite3/src/update.c
+++ b/lib/libsqlite3/src/update.c
@@ -246,7 +246,7 @@ void sqlite3Update(
   }
   for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){
     int reg;
-    if( hasFK || chngRowid ){
+    if( hasFK || chngRowid || pIdx->pPartIdxWhere ){
       reg = ++pParse->nMem;
     }else{
       reg = 0;
@@ -318,7 +318,7 @@ void sqlite3Update(
       pParse, pTabList, pWhere, 0, 0, WHERE_ONEPASS_DESIRED, 0
   );
   if( pWInfo==0 ) goto update_cleanup;
-  okOnePass = pWInfo->okOnePass;
+  okOnePass = sqlite3WhereOkOnePass(pWInfo);
 
   /* Remember the rowid of every item to be updated.
   */
diff --git a/lib/libsqlite3/src/vacuum.c b/lib/libsqlite3/src/vacuum.c
index 4afb2cca64d..4ba09fd4d99 100644
--- a/lib/libsqlite3/src/vacuum.c
+++ b/lib/libsqlite3/src/vacuum.c
@@ -111,7 +111,7 @@ int sqlite3RunVacuum(char **pzErrMsg, sqlite3 *db){
     sqlite3SetString(pzErrMsg, db, "cannot VACUUM from within a transaction");
     return SQLITE_ERROR;
   }
-  if( db->activeVdbeCnt>1 ){
+  if( db->nVdbeActive>1 ){
     sqlite3SetString(pzErrMsg, db,"cannot VACUUM - SQL statements in progress");
     return SQLITE_ERROR;
   }
diff --git a/lib/libsqlite3/src/vdbe.c b/lib/libsqlite3/src/vdbe.c
index f343e13d4e9..6c825e4e9a0 100644
--- a/lib/libsqlite3/src/vdbe.c
+++ b/lib/libsqlite3/src/vdbe.c
@@ -497,19 +497,6 @@ static int checkSavepointCount(sqlite3 *db){
 }
 #endif
 
-/*
-** Transfer error message text from an sqlite3_vtab.zErrMsg (text stored
-** in memory obtained from sqlite3_malloc) into a Vdbe.zErrMsg (text stored
-** in memory obtained from sqlite3DbMalloc).
-*/
-static void importVtabErrMsg(Vdbe *p, sqlite3_vtab *pVtab){
-  sqlite3 *db = p->db;
-  sqlite3DbFree(db, p->zErrMsg);
-  p->zErrMsg = sqlite3DbStrDup(db, pVtab->zErrMsg);
-  sqlite3_free(pVtab->zErrMsg);
-  pVtab->zErrMsg = 0;
-}
-
 
 /*
 ** Execute as much of a VDBE program as we can then return.
@@ -552,16 +539,16 @@ int sqlite3VdbeExec(
   sqlite3 *db = p->db;       /* The database */
   u8 resetSchemaOnFault = 0; /* Reset schema after an error if positive */
   u8 encoding = ENC(db);     /* The database encoding */
+  int iCompare = 0;          /* Result of last OP_Compare operation */
+  unsigned nVmStep = 0;      /* Number of virtual machine steps */
 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
-  int checkProgress;         /* True if progress callbacks are enabled */
-  int nProgressOps = 0;      /* Opcodes executed since progress callback. */
+  unsigned nProgressLimit = 0;/* Invoke xProgress() when nVmStep reaches this */
 #endif
   Mem *aMem = p->aMem;       /* Copy of p->aMem */
   Mem *pIn1 = 0;             /* 1st input operand */
   Mem *pIn2 = 0;             /* 2nd input operand */
   Mem *pIn3 = 0;             /* 3rd input operand */
   Mem *pOut = 0;             /* Output operand */
-  int iCompare = 0;          /* Result of last OP_Compare operation */
   int *aPermute = 0;         /* Permutation of columns for OP_Compare */
   i64 lastRowid = db->lastRowid;  /* Saved value of the last insert ROWID */
 #ifdef VDBE_PROFILE
@@ -578,6 +565,7 @@ int sqlite3VdbeExec(
     goto no_mem;
   }
   assert( p->rc==SQLITE_OK || p->rc==SQLITE_BUSY );
+  assert( p->bIsReader || p->readOnly!=0 );
   p->rc = SQLITE_OK;
   assert( p->explain==0 );
   p->pResultSet = 0;
@@ -585,7 +573,15 @@ int sqlite3VdbeExec(
   CHECK_FOR_INTERRUPT;
   sqlite3VdbeIOTraceSql(p);
 #ifndef SQLITE_OMIT_PROGRESS_CALLBACK
-  checkProgress = db->xProgress!=0;
+  if( db->xProgress ){
+    assert( 0 < db->nProgressOps );
+    nProgressLimit = (unsigned)p->aCounter[SQLITE_STMTSTATUS_VM_STEP];
+    if( nProgressLimit==0 ){
+      nProgressLimit = db->nProgressOps;
+    }else{
+      nProgressLimit %= (unsigned)db->nProgressOps;
+    }
+  }
 #endif
 #ifdef SQLITE_DEBUG
   sqlite3BeginBenignMalloc();
@@ -606,6 +602,7 @@ int sqlite3VdbeExec(
     origPc = pc;
     start = sqlite3Hwtime();
 #endif
+    nVmStep++;
     pOp = &aOp[pc];
 
     /* Only allow tracing if SQLITE_DEBUG is defined.
@@ -633,27 +630,6 @@ int sqlite3VdbeExec(
     }
 #endif
 
-#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
-    /* Call the progress callback if it is configured and the required number
-    ** of VDBE ops have been executed (either since this invocation of
-    ** sqlite3VdbeExec() or since last time the progress callback was called).
-    ** If the progress callback returns non-zero, exit the virtual machine with
-    ** a return code SQLITE_ABORT.
-    */
-    if( checkProgress ){
-      if( db->nProgressOps==nProgressOps ){
-        int prc;
-        prc = db->xProgress(db->pProgressArg);
-        if( prc!=0 ){
-          rc = SQLITE_INTERRUPT;
-          goto vdbe_error_halt;
-        }
-        nProgressOps = 0;
-      }
-      nProgressOps++;
-    }
-#endif
-
     /* On any opcode with the "out2-prerelease" tag, free any
     ** external allocations out of mem[p2] and set mem[p2] to be
     ** an undefined integer.  Opcodes will either fill in the integer
@@ -746,8 +722,40 @@ int sqlite3VdbeExec(
 ** the program.
 */
 case OP_Goto: {             /* jump */
-  CHECK_FOR_INTERRUPT;
   pc = pOp->p2 - 1;
+
+  /* Opcodes that are used as the bottom of a loop (OP_Next, OP_Prev,
+  ** OP_VNext, OP_RowSetNext, or OP_SorterNext) all jump here upon
+  ** completion.  Check to see if sqlite3_interrupt() has been called
+  ** or if the progress callback needs to be invoked. 
+  **
+  ** This code uses unstructured "goto" statements and does not look clean.
+  ** But that is not due to sloppy coding habits. The code is written this
+  ** way for performance, to avoid having to run the interrupt and progress
+  ** checks on every opcode.  This helps sqlite3_step() to run about 1.5%
+  ** faster according to "valgrind --tool=cachegrind" */
+check_for_interrupt:
+  CHECK_FOR_INTERRUPT;
+#ifndef SQLITE_OMIT_PROGRESS_CALLBACK
+  /* Call the progress callback if it is configured and the required number
+  ** of VDBE ops have been executed (either since this invocation of
+  ** sqlite3VdbeExec() or since last time the progress callback was called).
+  ** If the progress callback returns non-zero, exit the virtual machine with
+  ** a return code SQLITE_ABORT.
+  */
+  if( db->xProgress!=0 && nVmStep>=nProgressLimit ){
+    int prc;
+    prc = db->xProgress(db->pProgressArg);
+    if( prc!=0 ){
+      rc = SQLITE_INTERRUPT;
+      goto vdbe_error_halt;
+    }
+    if( db->xProgress!=0 ){
+      nProgressLimit = nVmStep + db->nProgressOps - (nVmStep%db->nProgressOps);
+    }
+  }
+#endif
+  
   break;
 }
 
@@ -866,7 +874,7 @@ case OP_Halt: {
     p->rc = rc = SQLITE_BUSY;
   }else{
     assert( rc==SQLITE_OK || (p->rc&0xff)==SQLITE_CONSTRAINT );
-    assert( rc==SQLITE_OK || db->nDeferredCons>0 );
+    assert( rc==SQLITE_OK || db->nDeferredCons>0 || db->nDeferredImmCons>0 );
     rc = p->rc ? SQLITE_ERROR : SQLITE_DONE;
   }
   goto vdbe_return;
@@ -1412,19 +1420,14 @@ case OP_Function: {
     REGISTER_TRACE(pOp->p2+i, pArg);
   }
 
-  assert( pOp->p4type==P4_FUNCDEF || pOp->p4type==P4_VDBEFUNC );
-  if( pOp->p4type==P4_FUNCDEF ){
-    ctx.pFunc = pOp->p4.pFunc;
-    ctx.pVdbeFunc = 0;
-  }else{
-    ctx.pVdbeFunc = (VdbeFunc*)pOp->p4.pVdbeFunc;
-    ctx.pFunc = ctx.pVdbeFunc->pFunc;
-  }
-
+  assert( pOp->p4type==P4_FUNCDEF );
+  ctx.pFunc = pOp->p4.pFunc;
   ctx.s.flags = MEM_Null;
   ctx.s.db = db;
   ctx.s.xDel = 0;
   ctx.s.zMalloc = 0;
+  ctx.iOp = pc;
+  ctx.pVdbe = p;
 
   /* The output cell may already have a buffer allocated. Move
   ** the pointer to ctx.s so in case the user-function can use
@@ -1433,7 +1436,7 @@ case OP_Function: {
   sqlite3VdbeMemMove(&ctx.s, pOut);
   MemSetTypeFlag(&ctx.s, MEM_Null);
 
-  ctx.isError = 0;
+  ctx.fErrorOrAux = 0;
   if( ctx.pFunc->flags & SQLITE_FUNC_NEEDCOLL ){
     assert( pOp>aOp );
     assert( pOp[-1].p4type==P4_COLLSEQ );
@@ -1444,15 +1447,6 @@ case OP_Function: {
   (*ctx.pFunc->xFunc)(&ctx, n, apVal); /* IMP: R-24505-23230 */
   lastRowid = db->lastRowid;
 
-  /* If any auxiliary data functions have been called by this user function,
-  ** immediately call the destructor for any non-static values.
-  */
-  if( ctx.pVdbeFunc ){
-    sqlite3VdbeDeleteAuxData(ctx.pVdbeFunc, pOp->p1);
-    pOp->p4.pVdbeFunc = ctx.pVdbeFunc;
-    pOp->p4type = P4_VDBEFUNC;
-  }
-
   if( db->mallocFailed ){
     /* Even though a malloc() has failed, the implementation of the
     ** user function may have called an sqlite3_result_XXX() function
@@ -1464,9 +1458,12 @@ case OP_Function: {
   }
 
   /* If the function returned an error, throw an exception */
-  if( ctx.isError ){
-    sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3_value_text(&ctx.s));
-    rc = ctx.isError;
+  if( ctx.fErrorOrAux ){
+    if( ctx.isError ){
+      sqlite3SetString(&p->zErrMsg, db, "%s", sqlite3_value_text(&ctx.s));
+      rc = ctx.isError;
+    }
+    sqlite3VdbeDeleteAuxData(p, pc, pOp->p1);
   }
 
   /* Copy the result of the function into register P3 */
@@ -1838,12 +1835,12 @@ case OP_Ge: {             /* same as TK_GE, jump, in1, in3 */
       ** then the result is always NULL.
       ** The jump is taken if the SQLITE_JUMPIFNULL bit is set.
       */
-      if( pOp->p5 & SQLITE_STOREP2 ){
+      if( pOp->p5 & SQLITE_JUMPIFNULL ){
+        pc = pOp->p2-1;
+      }else if( pOp->p5 & SQLITE_STOREP2 ){
         pOut = &aMem[pOp->p2];
         MemSetTypeFlag(pOut, MEM_Null);
         REGISTER_TRACE(pOp->p2, pOut);
-      }else if( pOp->p5 & SQLITE_JUMPIFNULL ){
-        pc = pOp->p2-1;
       }
       break;
     }
@@ -2683,9 +2680,10 @@ case OP_Savepoint: {
   assert( p1==SAVEPOINT_BEGIN||p1==SAVEPOINT_RELEASE||p1==SAVEPOINT_ROLLBACK );
   assert( db->pSavepoint || db->isTransactionSavepoint==0 );
   assert( checkSavepointCount(db) );
+  assert( p->bIsReader );
 
   if( p1==SAVEPOINT_BEGIN ){
-    if( db->writeVdbeCnt>0 ){
+    if( db->nVdbeWrite>0 ){
       /* A new savepoint cannot be created if there are active write 
       ** statements (i.e. open read/write incremental blob handles).
       */
@@ -2725,6 +2723,7 @@ case OP_Savepoint: {
         pNew->pNext = db->pSavepoint;
         db->pSavepoint = pNew;
         pNew->nDeferredCons = db->nDeferredCons;
+        pNew->nDeferredImmCons = db->nDeferredImmCons;
       }
     }
   }else{
@@ -2742,7 +2741,7 @@ case OP_Savepoint: {
     if( !pSavepoint ){
       sqlite3SetString(&p->zErrMsg, db, "no such savepoint: %s", zName);
       rc = SQLITE_ERROR;
-    }else if( db->writeVdbeCnt>0 && p1==SAVEPOINT_RELEASE ){
+    }else if( db->nVdbeWrite>0 && p1==SAVEPOINT_RELEASE ){
       /* It is not possible to release (commit) a savepoint if there are 
       ** active write statements.
       */
@@ -2812,6 +2811,7 @@ case OP_Savepoint: {
         }
       }else{
         db->nDeferredCons = pSavepoint->nDeferredCons;
+        db->nDeferredImmCons = pSavepoint->nDeferredImmCons;
       }
 
       if( !isTransaction ){
@@ -2843,10 +2843,11 @@ case OP_AutoCommit: {
   turnOnAC = desiredAutoCommit && !db->autoCommit;
   assert( desiredAutoCommit==1 || desiredAutoCommit==0 );
   assert( desiredAutoCommit==1 || iRollback==0 );
-  assert( db->activeVdbeCnt>0 );  /* At least this one VM is active */
+  assert( db->nVdbeActive>0 );  /* At least this one VM is active */
+  assert( p->bIsReader );
 
 #if 0
-  if( turnOnAC && iRollback && db->activeVdbeCnt>1 ){
+  if( turnOnAC && iRollback && db->nVdbeActive>1 ){
     /* If this instruction implements a ROLLBACK and other VMs are
     ** still running, and a transaction is active, return an error indicating
     ** that the other VMs must complete first. 
@@ -2856,7 +2857,7 @@ case OP_AutoCommit: {
     rc = SQLITE_BUSY;
   }else
 #endif
-  if( turnOnAC && !iRollback && db->writeVdbeCnt>0 ){
+  if( turnOnAC && !iRollback && db->nVdbeWrite>0 ){
     /* If this instruction implements a COMMIT and other VMs are writing
     ** return an error indicating that the other VMs must complete first. 
     */
@@ -2914,8 +2915,8 @@ case OP_AutoCommit: {
 ** other process can start another write transaction while this transaction is
 ** underway.  Starting a write transaction also creates a rollback journal. A
 ** write transaction must be started before any changes can be made to the
-** database.  If P2 is 2 or greater then an EXCLUSIVE lock is also obtained
-** on the file.
+** database.  If P2 is greater than or equal to 2 then an EXCLUSIVE lock is
+** also obtained on the file.
 **
 ** If a write-transaction is started and the Vdbe.usesStmtJournal flag is
 ** true (this flag is set if the Vdbe may modify more than one row and may
@@ -2932,8 +2933,14 @@ case OP_AutoCommit: {
 case OP_Transaction: {
   Btree *pBt;
 
+  assert( p->bIsReader );
+  assert( p->readOnly==0 || pOp->p2==0 );
   assert( pOp->p1>=0 && pOp->p1<db->nDb );
   assert( (p->btreeMask & (((yDbMask)1)<<pOp->p1))!=0 );
+  if( pOp->p2 && (db->flags & SQLITE_QueryOnly)!=0 ){
+    rc = SQLITE_READONLY;
+    goto abort_due_to_error;
+  }
   pBt = db->aDb[pOp->p1].pBt;
 
   if( pBt ){
@@ -2948,7 +2955,7 @@ case OP_Transaction: {
     }
 
     if( pOp->p2 && p->usesStmtJournal 
-     && (db->autoCommit==0 || db->activeVdbeCnt>1) 
+     && (db->autoCommit==0 || db->nVdbeRead>1) 
     ){
       assert( sqlite3BtreeIsInTrans(pBt) );
       if( p->iStatement==0 ){
@@ -2966,6 +2973,7 @@ case OP_Transaction: {
       ** counter. If the statement transaction needs to be rolled back,
       ** the value of this counter needs to be restored too.  */
       p->nStmtDefCons = db->nDeferredCons;
+      p->nStmtDefImmCons = db->nDeferredImmCons;
     }
   }
   break;
@@ -2988,6 +2996,7 @@ case OP_ReadCookie: {               /* out2-prerelease */
   int iDb;
   int iCookie;
 
+  assert( p->bIsReader );
   iDb = pOp->p1;
   iCookie = pOp->p3;
   assert( pOp->p3<SQLITE_N_BTREE_META );
@@ -3015,6 +3024,7 @@ case OP_SetCookie: {       /* in3 */
   assert( pOp->p2<SQLITE_N_BTREE_META );
   assert( pOp->p1>=0 && pOp->p1<db->nDb );
   assert( (p->btreeMask & (((yDbMask)1)<<pOp->p1))!=0 );
+  assert( p->readOnly==0 );
   pDb = &db->aDb[pOp->p1];
   assert( pDb->pBt!=0 );
   assert( sqlite3SchemaMutexHeld(db, pOp->p1, 0) );
@@ -3065,6 +3075,7 @@ case OP_VerifyCookie: {
   assert( pOp->p1>=0 && pOp->p1<db->nDb );
   assert( (p->btreeMask & (((yDbMask)1)<<pOp->p1))!=0 );
   assert( sqlite3SchemaMutexHeld(db, pOp->p1, 0) );
+  assert( p->bIsReader );
   pBt = db->aDb[pOp->p1].pBt;
   if( pBt ){
     sqlite3BtreeGetMeta(pBt, BTREE_SCHEMA_VERSION, (u32 *)&iMeta);
@@ -3160,6 +3171,8 @@ case OP_OpenWrite: {
 
   assert( (pOp->p5&(OPFLAG_P2ISREG|OPFLAG_BULKCSR))==pOp->p5 );
   assert( pOp->opcode==OP_OpenWrite || pOp->p5==0 );
+  assert( p->bIsReader );
+  assert( pOp->opcode==OP_OpenRead || p->readOnly==0 );
 
   if( p->expired ){
     rc = SQLITE_ABORT;
@@ -4324,7 +4337,7 @@ case OP_Rowid: {                 /* out2-prerelease */
     pModule = pVtab->pModule;
     assert( pModule->xRowid );
     rc = pModule->xRowid(pC->pVtabCursor, &v);
-    importVtabErrMsg(p, pVtab);
+    sqlite3VtabImportErrmsg(p, pVtab);
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
   }else{
     assert( pC->pCursor!=0 );
@@ -4412,7 +4425,7 @@ case OP_Sort: {        /* jump */
   sqlite3_sort_count++;
   sqlite3_search_count--;
 #endif
-  p->aCounter[SQLITE_STMTSTATUS_SORT-1]++;
+  p->aCounter[SQLITE_STMTSTATUS_SORT]++;
   /* Fall through into OP_Rewind */
 }
 /* Opcode: Rewind P1 P2 * * *
@@ -4490,9 +4503,8 @@ case OP_Next: {        /* jump */
   VdbeCursor *pC;
   int res;
 
-  CHECK_FOR_INTERRUPT;
   assert( pOp->p1>=0 && pOp->p1<p->nCursor );
-  assert( pOp->p5<=ArraySize(p->aCounter) );
+  assert( pOp->p5<ArraySize(p->aCounter) );
   pC = p->apCsr[pOp->p1];
   if( pC==0 ){
     break;  /* See ticket #2273 */
@@ -4502,7 +4514,7 @@ case OP_Next: {        /* jump */
     assert( pOp->opcode==OP_SorterNext );
     rc = sqlite3VdbeSorterNext(db, pC, &res);
   }else{
-    res = 1;
+    /* res = 1; // Always initialized by the xAdvance() call */
     assert( pC->deferredMoveto==0 );
     assert( pC->pCursor );
     assert( pOp->opcode!=OP_Next || pOp->p4.xAdvance==sqlite3BtreeNext );
@@ -4513,13 +4525,13 @@ case OP_Next: {        /* jump */
   pC->cacheStatus = CACHE_STALE;
   if( res==0 ){
     pc = pOp->p2 - 1;
-    if( pOp->p5 ) p->aCounter[pOp->p5-1]++;
+    p->aCounter[pOp->p5]++;
 #ifdef SQLITE_TEST
     sqlite3_search_count++;
 #endif
   }
   pC->rowidIsValid = 0;
-  break;
+  goto check_for_interrupt;
 }
 
 /* Opcode: IdxInsert P1 P2 P3 * P5
@@ -4730,15 +4742,18 @@ case OP_Destroy: {     /* out2-prerelease */
   Vdbe *pVdbe;
   int iDb;
 
+  assert( p->readOnly==0 );
 #ifndef SQLITE_OMIT_VIRTUALTABLE
   iCnt = 0;
   for(pVdbe=db->pVdbe; pVdbe; pVdbe = pVdbe->pNext){
-    if( pVdbe->magic==VDBE_MAGIC_RUN && pVdbe->inVtabMethod<2 && pVdbe->pc>=0 ){
+    if( pVdbe->magic==VDBE_MAGIC_RUN && pVdbe->bIsReader 
+     && pVdbe->inVtabMethod<2 && pVdbe->pc>=0 
+    ){
       iCnt++;
     }
   }
 #else
-  iCnt = db->activeVdbeCnt;
+  iCnt = db->nVdbeRead;
 #endif
   pOut->flags = MEM_Null;
   if( iCnt>1 ){
@@ -4785,6 +4800,7 @@ case OP_Clear: {
   int nChange;
  
   nChange = 0;
+  assert( p->readOnly==0 );
   assert( (p->btreeMask & (((yDbMask)1)<<pOp->p2))!=0 );
   rc = sqlite3BtreeClearTable(
       db->aDb[pOp->p2].pBt, pOp->p1, (pOp->p3 ? &nChange : 0)
@@ -4831,6 +4847,7 @@ case OP_CreateTable: {          /* out2-prerelease */
   pgno = 0;
   assert( pOp->p1>=0 && pOp->p1<db->nDb );
   assert( (p->btreeMask & (((yDbMask)1)<<pOp->p1))!=0 );
+  assert( p->readOnly==0 );
   pDb = &db->aDb[pOp->p1];
   assert( pDb->pBt!=0 );
   if( pOp->opcode==OP_CreateTable ){
@@ -4978,7 +4995,8 @@ case OP_IntegrityCk: {
   int nErr;       /* Number of errors reported */
   char *z;        /* Text of the error report */
   Mem *pnErr;     /* Register keeping track of errors remaining */
-  
+
+  assert( p->bIsReader );
   nRoot = pOp->p2;
   assert( nRoot>0 );
   aRoot = sqlite3DbMallocRaw(db, sizeof(int)*(nRoot+1) );
@@ -5039,7 +5057,7 @@ case OP_RowSetAdd: {       /* in1, in2 */
 */
 case OP_RowSetRead: {       /* jump, in1, out3 */
   i64 val;
-  CHECK_FOR_INTERRUPT;
+
   pIn1 = &aMem[pOp->p1];
   if( (pIn1->flags & MEM_RowSet)==0 
    || sqlite3RowSetNext(pIn1->u.pRowSet, &val)==0
@@ -5051,7 +5069,7 @@ case OP_RowSetRead: {       /* jump, in1, out3 */
     /* A value was pulled from the index */
     sqlite3VdbeMemSetInt64(&aMem[pOp->p3], val);
   }
-  break;
+  goto check_for_interrupt;
 }
 
 /* Opcode: RowSetTest P1 P2 P3 P4
@@ -5265,7 +5283,9 @@ case OP_Param: {           /* out2-prerelease */
 ** statement counter is incremented (immediate foreign key constraints).
 */
 case OP_FkCounter: {
-  if( pOp->p1 ){
+  if( db->flags & SQLITE_DeferFKs ){
+    db->nDeferredImmCons += pOp->p2;
+  }else if( pOp->p1 ){
     db->nDeferredCons += pOp->p2;
   }else{
     p->nFkConstraint += pOp->p2;
@@ -5286,9 +5306,9 @@ case OP_FkCounter: {
 */
 case OP_FkIfZero: {         /* jump */
   if( pOp->p1 ){
-    if( db->nDeferredCons==0 ) pc = pOp->p2-1;
+    if( db->nDeferredCons==0 && db->nDeferredImmCons==0 ) pc = pOp->p2-1;
   }else{
-    if( p->nFkConstraint==0 ) pc = pOp->p2-1;
+    if( p->nFkConstraint==0 && db->nDeferredImmCons==0 ) pc = pOp->p2-1;
   }
   break;
 }
@@ -5484,6 +5504,7 @@ case OP_Checkpoint: {
   int aRes[3];                    /* Results */
   Mem *pMem;                      /* Write results here */
 
+  assert( p->readOnly==0 );
   aRes[0] = 0;
   aRes[1] = aRes[2] = -1;
   assert( pOp->p2==SQLITE_CHECKPOINT_PASSIVE
@@ -5533,6 +5554,7 @@ case OP_JournalMode: {    /* out2-prerelease */
        || eNew==PAGER_JOURNALMODE_QUERY
   );
   assert( pOp->p1>=0 && pOp->p1<db->nDb );
+  assert( p->readOnly==0 );
 
   pBt = db->aDb[pOp->p1].pBt;
   pPager = sqlite3BtreePager(pBt);
@@ -5556,7 +5578,7 @@ case OP_JournalMode: {    /* out2-prerelease */
   if( (eNew!=eOld)
    && (eOld==PAGER_JOURNALMODE_WAL || eNew==PAGER_JOURNALMODE_WAL)
   ){
-    if( !db->autoCommit || db->activeVdbeCnt>1 ){
+    if( !db->autoCommit || db->nVdbeRead>1 ){
       rc = SQLITE_ERROR;
       sqlite3SetString(&p->zErrMsg, db, 
           "cannot change %s wal mode from within a transaction",
@@ -5615,6 +5637,7 @@ case OP_JournalMode: {    /* out2-prerelease */
 ** a transaction.
 */
 case OP_Vacuum: {
+  assert( p->readOnly==0 );
   rc = sqlite3RunVacuum(&p->zErrMsg, db);
   break;
 }
@@ -5632,6 +5655,7 @@ case OP_IncrVacuum: {        /* jump */
 
   assert( pOp->p1>=0 && pOp->p1<db->nDb );
   assert( (p->btreeMask & (((yDbMask)1)<<pOp->p1))!=0 );
+  assert( p->readOnly==0 );
   pBt = db->aDb[pOp->p1].pBt;
   rc = sqlite3BtreeIncrVacuum(pBt);
   if( rc==SQLITE_DONE ){
@@ -5706,7 +5730,7 @@ case OP_VBegin: {
   VTable *pVTab;
   pVTab = pOp->p4.pVtab;
   rc = sqlite3VtabBegin(db, pVTab);
-  if( pVTab ) importVtabErrMsg(p, pVTab->pVtab);
+  if( pVTab ) sqlite3VtabImportErrmsg(p, pVTab->pVtab);
   break;
 }
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
@@ -5750,13 +5774,14 @@ case OP_VOpen: {
   sqlite3_vtab *pVtab;
   sqlite3_module *pModule;
 
+  assert( p->bIsReader );
   pCur = 0;
   pVtabCursor = 0;
   pVtab = pOp->p4.pVtab->pVtab;
   pModule = (sqlite3_module *)pVtab->pModule;
   assert(pVtab && pModule);
   rc = pModule->xOpen(pVtab, &pVtabCursor);
-  importVtabErrMsg(p, pVtab);
+  sqlite3VtabImportErrmsg(p, pVtab);
   if( SQLITE_OK==rc ){
     /* Initialize sqlite3_vtab_cursor base class */
     pVtabCursor->pVtab = pVtab;
@@ -5834,7 +5859,7 @@ case OP_VFilter: {   /* jump */
     p->inVtabMethod = 1;
     rc = pModule->xFilter(pVtabCursor, iQuery, pOp->p4.z, nArg, apArg);
     p->inVtabMethod = 0;
-    importVtabErrMsg(p, pVtab);
+    sqlite3VtabImportErrmsg(p, pVtab);
     if( rc==SQLITE_OK ){
       res = pModule->xEof(pVtabCursor);
     }
@@ -5885,7 +5910,7 @@ case OP_VColumn: {
   MemSetTypeFlag(&sContext.s, MEM_Null);
 
   rc = pModule->xColumn(pCur->pVtabCursor, &sContext, pOp->p2);
-  importVtabErrMsg(p, pVtab);
+  sqlite3VtabImportErrmsg(p, pVtab);
   if( sContext.isError ){
     rc = sContext.isError;
   }
@@ -5938,7 +5963,7 @@ case OP_VNext: {   /* jump */
   p->inVtabMethod = 1;
   rc = pModule->xNext(pCur->pVtabCursor);
   p->inVtabMethod = 0;
-  importVtabErrMsg(p, pVtab);
+  sqlite3VtabImportErrmsg(p, pVtab);
   if( rc==SQLITE_OK ){
     res = pModule->xEof(pCur->pVtabCursor);
   }
@@ -5947,7 +5972,7 @@ case OP_VNext: {   /* jump */
     /* If there is data, jump to P2 */
     pc = pOp->p2 - 1;
   }
-  break;
+  goto check_for_interrupt;
 }
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
 
@@ -5966,6 +5991,7 @@ case OP_VRename: {
   pName = &aMem[pOp->p1];
   assert( pVtab->pModule->xRename );
   assert( memIsValid(pName) );
+  assert( p->readOnly==0 );
   REGISTER_TRACE(pOp->p1, pName);
   assert( pName->flags & MEM_Str );
   testcase( pName->enc==SQLITE_UTF8 );
@@ -5974,7 +6000,7 @@ case OP_VRename: {
   rc = sqlite3VdbeChangeEncoding(pName, SQLITE_UTF8);
   if( rc==SQLITE_OK ){
     rc = pVtab->pModule->xRename(pVtab, pName->z);
-    importVtabErrMsg(p, pVtab);
+    sqlite3VtabImportErrmsg(p, pVtab);
     p->expired = 0;
   }
   break;
@@ -6017,6 +6043,7 @@ case OP_VUpdate: {
   assert( pOp->p2==1        || pOp->p5==OE_Fail   || pOp->p5==OE_Rollback 
        || pOp->p5==OE_Abort || pOp->p5==OE_Ignore || pOp->p5==OE_Replace
   );
+  assert( p->readOnly==0 );
   pVtab = pOp->p4.pVtab->pVtab;
   pModule = (sqlite3_module *)pVtab->pModule;
   nArg = pOp->p2;
@@ -6035,7 +6062,7 @@ case OP_VUpdate: {
     db->vtabOnConflict = pOp->p5;
     rc = pModule->xUpdate(pVtab, nArg, apArg, &rowid);
     db->vtabOnConflict = vtabOnConflict;
-    importVtabErrMsg(p, pVtab);
+    sqlite3VtabImportErrmsg(p, pVtab);
     if( rc==SQLITE_OK && pOp->p1 ){
       assert( nArg>1 && apArg[0] && (apArg[0]->flags&MEM_Null) );
       db->lastRowid = lastRowid = rowid;
@@ -6200,6 +6227,8 @@ vdbe_error_halt:
   ** top. */
 vdbe_return:
   db->lastRowid = lastRowid;
+  testcase( nVmStep>0 );
+  p->aCounter[SQLITE_STMTSTATUS_VM_STEP] += (int)nVmStep;
   sqlite3VdbeLeave(p);
   return rc;
 
diff --git a/lib/libsqlite3/src/vdbe.h b/lib/libsqlite3/src/vdbe.h
index fa7b31b7270..a6cc9154440 100644
--- a/lib/libsqlite3/src/vdbe.h
+++ b/lib/libsqlite3/src/vdbe.h
@@ -30,7 +30,6 @@ typedef struct Vdbe Vdbe;
 ** The names of the following types declared in vdbeInt.h are required
 ** for the VdbeOp definition.
 */
-typedef struct VdbeFunc VdbeFunc;
 typedef struct Mem Mem;
 typedef struct SubProgram SubProgram;
 
@@ -54,7 +53,6 @@ struct VdbeOp {
     i64 *pI64;             /* Used when p4type is P4_INT64 */
     double *pReal;         /* Used when p4type is P4_REAL */
     FuncDef *pFunc;        /* Used when p4type is P4_FUNCDEF */
-    VdbeFunc *pVdbeFunc;   /* Used when p4type is P4_VDBEFUNC */
     CollSeq *pColl;        /* Used when p4type is P4_COLLSEQ */
     Mem *pMem;             /* Used when p4type is P4_MEM */
     VTable *pVtab;         /* Used when p4type is P4_VTAB */
@@ -108,7 +106,6 @@ typedef struct VdbeOpList VdbeOpList;
 #define P4_COLLSEQ  (-4)  /* P4 is a pointer to a CollSeq structure */
 #define P4_FUNCDEF  (-5)  /* P4 is a pointer to a FuncDef structure */
 #define P4_KEYINFO  (-6)  /* P4 is a pointer to a KeyInfo structure */
-#define P4_VDBEFUNC (-7)  /* P4 is a pointer to a VdbeFunc structure */
 #define P4_MEM      (-8)  /* P4 is a pointer to a Mem*    structure */
 #define P4_TRANSIENT  0   /* P4 is a pointer to a transient string */
 #define P4_VTAB     (-10) /* P4 is a pointer to an sqlite3_vtab structure */
@@ -207,7 +204,7 @@ sqlite3 *sqlite3VdbeDb(Vdbe*);
 void sqlite3VdbeSetSql(Vdbe*, const char *z, int n, int);
 void sqlite3VdbeSwap(Vdbe*,Vdbe*);
 VdbeOp *sqlite3VdbeTakeOpArray(Vdbe*, int*, int*);
-sqlite3_value *sqlite3VdbeGetValue(Vdbe*, int, u8);
+sqlite3_value *sqlite3VdbeGetBoundValue(Vdbe*, int, u8);
 void sqlite3VdbeSetVarmask(Vdbe*, int);
 #ifndef SQLITE_OMIT_TRACE
   char *sqlite3VdbeExpandSql(Vdbe*, const char*);
diff --git a/lib/libsqlite3/src/vdbeInt.h b/lib/libsqlite3/src/vdbeInt.h
index 3a5b4028bbd..a699c414b0a 100644
--- a/lib/libsqlite3/src/vdbeInt.h
+++ b/lib/libsqlite3/src/vdbeInt.h
@@ -44,6 +44,9 @@ typedef struct VdbeSorter VdbeSorter;
 /* Opaque type used by the explainer */
 typedef struct Explain Explain;
 
+/* Elements of the linked list at Vdbe.pAuxData */
+typedef struct AuxData AuxData;
+
 /*
 ** A cursor is a pointer into a single BTree within a database file.
 ** The cursor can seek to a BTree entry with a particular key, or
@@ -230,23 +233,19 @@ struct Mem {
 #define memIsValid(M)  ((M)->flags & MEM_Invalid)==0
 #endif
 
-
-/* A VdbeFunc is just a FuncDef (defined in sqliteInt.h) that contains
-** additional information about auxiliary information bound to arguments
-** of the function.  This is used to implement the sqlite3_get_auxdata()
-** and sqlite3_set_auxdata() APIs.  The "auxdata" is some auxiliary data
-** that can be associated with a constant argument to a function.  This
-** allows functions such as "regexp" to compile their constant regular
-** expression argument once and reused the compiled code for multiple
-** invocations.
+/*
+** Each auxilliary data pointer stored by a user defined function 
+** implementation calling sqlite3_set_auxdata() is stored in an instance
+** of this structure. All such structures associated with a single VM
+** are stored in a linked list headed at Vdbe.pAuxData. All are destroyed
+** when the VM is halted (if not before).
 */
-struct VdbeFunc {
-  FuncDef *pFunc;               /* The definition of the function */
-  int nAux;                     /* Number of entries allocated for apAux[] */
-  struct AuxData {
-    void *pAux;                   /* Aux data for the i-th argument */
-    void (*xDelete)(void *);      /* Destructor for the aux data */
-  } apAux[1];                   /* One slot for each function argument */
+struct AuxData {
+  int iOp;                        /* Instruction number of OP_Function opcode */
+  int iArg;                       /* Index of function argument. */
+  void *pAux;                     /* Aux data pointer */
+  void (*xDelete)(void *);        /* Destructor for the aux data */
+  AuxData *pNext;                 /* Next element in list */
 };
 
 /*
@@ -264,12 +263,14 @@ struct VdbeFunc {
 */
 struct sqlite3_context {
   FuncDef *pFunc;       /* Pointer to function information.  MUST BE FIRST */
-  VdbeFunc *pVdbeFunc;  /* Auxilary data, if created. */
   Mem s;                /* The return value is stored here */
   Mem *pMem;            /* Memory cell used to store aggregate context */
   CollSeq *pColl;       /* Collating sequence */
+  Vdbe *pVdbe;          /* The VM that owns this context */
+  int iOp;              /* Instruction number of OP_Function */
   int isError;          /* Error code returned by the function. */
-  int skipFlag;         /* Skip skip accumulator loading if true */
+  u8 skipFlag;          /* Skip skip accumulator loading if true */
+  u8 fErrorOrAux;       /* isError!=0 or pVdbe->pAuxData modified */
 };
 
 /*
@@ -337,19 +338,21 @@ struct Vdbe {
   bft expired:1;          /* True if the VM needs to be recompiled */
   bft runOnlyOnce:1;      /* Automatically expire on reset */
   bft usesStmtJournal:1;  /* True if uses a statement journal */
-  bft readOnly:1;         /* True for read-only statements */
+  bft readOnly:1;         /* True for statements that do not write */
+  bft bIsReader:1;        /* True for statements that read */
   bft isPrepareV2:1;      /* True if prepared with prepare_v2() */
   bft doingRerun:1;       /* True if rerunning after an auto-reprepare */
   int nChange;            /* Number of db changes made since last reset */
   yDbMask btreeMask;      /* Bitmask of db->aDb[] entries referenced */
   yDbMask lockMask;       /* Subset of btreeMask that requires a lock */
   int iStatement;         /* Statement number (or 0 if has not opened stmt) */
-  int aCounter[3];        /* Counters used by sqlite3_stmt_status() */
+  u32 aCounter[5];        /* Counters used by sqlite3_stmt_status() */
 #ifndef SQLITE_OMIT_TRACE
   i64 startTime;          /* Time when query started - used for profiling */
 #endif
   i64 nFkConstraint;      /* Number of imm. FK constraints this VM */
   i64 nStmtDefCons;       /* Number of def. constraints when stmt started */
+  i64 nStmtDefImmCons;    /* Number of def. imm constraints when stmt started */
   char *zSql;             /* Text of the SQL statement that generated this */
   void *pFree;            /* Free this when deleting the vdbe */
 #ifdef SQLITE_DEBUG
@@ -366,6 +369,7 @@ struct Vdbe {
   SubProgram *pProgram;   /* Linked list of all sub-programs used by VM */
   int nOnceFlag;          /* Size of array aOnceFlag[] */
   u8 *aOnceFlag;          /* Flags for OP_Once */
+  AuxData *pAuxData;      /* Linked list of auxdata allocations */
 };
 
 /*
@@ -389,7 +393,7 @@ u32 sqlite3VdbeSerialTypeLen(u32);
 u32 sqlite3VdbeSerialType(Mem*, int);
 u32 sqlite3VdbeSerialPut(unsigned char*, int, Mem*, int);
 u32 sqlite3VdbeSerialGet(const unsigned char*, u32, Mem*);
-void sqlite3VdbeDeleteAuxData(VdbeFunc*, int);
+void sqlite3VdbeDeleteAuxData(Vdbe*, int, int);
 
 int sqlite2BtreeKeyCompare(BtCursor *, const void *, int, int, int *);
 int sqlite3VdbeIdxKeyCompare(VdbeCursor*,UnpackedRecord*,int*);
diff --git a/lib/libsqlite3/src/vdbeapi.c b/lib/libsqlite3/src/vdbeapi.c
index 7c861e2d472..52c6b2a797b 100644
--- a/lib/libsqlite3/src/vdbeapi.c
+++ b/lib/libsqlite3/src/vdbeapi.c
@@ -211,12 +211,14 @@ void sqlite3_result_double(sqlite3_context *pCtx, double rVal){
 void sqlite3_result_error(sqlite3_context *pCtx, const char *z, int n){
   assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
   pCtx->isError = SQLITE_ERROR;
+  pCtx->fErrorOrAux = 1;
   sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF8, SQLITE_TRANSIENT);
 }
 #ifndef SQLITE_OMIT_UTF16
 void sqlite3_result_error16(sqlite3_context *pCtx, const void *z, int n){
   assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
   pCtx->isError = SQLITE_ERROR;
+  pCtx->fErrorOrAux = 1;
   sqlite3VdbeMemSetStr(&pCtx->s, z, n, SQLITE_UTF16NATIVE, SQLITE_TRANSIENT);
 }
 #endif
@@ -280,6 +282,7 @@ void sqlite3_result_zeroblob(sqlite3_context *pCtx, int n){
 }
 void sqlite3_result_error_code(sqlite3_context *pCtx, int errCode){
   pCtx->isError = errCode;
+  pCtx->fErrorOrAux = 1;
   if( pCtx->s.flags & MEM_Null ){
     sqlite3VdbeMemSetStr(&pCtx->s, sqlite3ErrStr(errCode), -1, 
                          SQLITE_UTF8, SQLITE_STATIC);
@@ -290,6 +293,7 @@ void sqlite3_result_error_code(sqlite3_context *pCtx, int errCode){
 void sqlite3_result_error_toobig(sqlite3_context *pCtx){
   assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
   pCtx->isError = SQLITE_TOOBIG;
+  pCtx->fErrorOrAux = 1;
   sqlite3VdbeMemSetStr(&pCtx->s, "string or blob too big", -1, 
                        SQLITE_UTF8, SQLITE_STATIC);
 }
@@ -299,6 +303,7 @@ void sqlite3_result_error_nomem(sqlite3_context *pCtx){
   assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
   sqlite3VdbeMemSetNull(&pCtx->s);
   pCtx->isError = SQLITE_NOMEM;
+  pCtx->fErrorOrAux = 1;
   pCtx->s.db->mallocFailed = 1;
 }
 
@@ -382,11 +387,13 @@ static int sqlite3Step(Vdbe *p){
     ** reset the interrupt flag.  This prevents a call to sqlite3_interrupt
     ** from interrupting a statement that has not yet started.
     */
-    if( db->activeVdbeCnt==0 ){
+    if( db->nVdbeActive==0 ){
       db->u1.isInterrupted = 0;
     }
 
-    assert( db->writeVdbeCnt>0 || db->autoCommit==0 || db->nDeferredCons==0 );
+    assert( db->nVdbeWrite>0 || db->autoCommit==0 
+        || (db->nDeferredCons==0 && db->nDeferredImmCons==0)
+    );
 
 #ifndef SQLITE_OMIT_TRACE
     if( db->xProfile && !db->init.busy ){
@@ -394,8 +401,9 @@ static int sqlite3Step(Vdbe *p){
     }
 #endif
 
-    db->activeVdbeCnt++;
-    if( p->readOnly==0 ) db->writeVdbeCnt++;
+    db->nVdbeActive++;
+    if( p->readOnly==0 ) db->nVdbeWrite++;
+    if( p->bIsReader ) db->nVdbeRead++;
     p->pc = 0;
   }
 #ifndef SQLITE_OMIT_EXPLAIN
@@ -404,9 +412,9 @@ static int sqlite3Step(Vdbe *p){
   }else
 #endif /* SQLITE_OMIT_EXPLAIN */
   {
-    db->vdbeExecCnt++;
+    db->nVdbeExec++;
     rc = sqlite3VdbeExec(p);
-    db->vdbeExecCnt--;
+    db->nVdbeExec--;
   }
 
 #ifndef SQLITE_OMIT_TRACE
@@ -581,14 +589,14 @@ void *sqlite3_aggregate_context(sqlite3_context *p, int nByte){
 ** the user-function defined by pCtx.
 */
 void *sqlite3_get_auxdata(sqlite3_context *pCtx, int iArg){
-  VdbeFunc *pVdbeFunc;
+  AuxData *pAuxData;
 
   assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
-  pVdbeFunc = pCtx->pVdbeFunc;
-  if( !pVdbeFunc || iArg>=pVdbeFunc->nAux || iArg<0 ){
-    return 0;
+  for(pAuxData=pCtx->pVdbe->pAuxData; pAuxData; pAuxData=pAuxData->pNext){
+    if( pAuxData->iOp==pCtx->iOp && pAuxData->iArg==iArg ) break;
   }
-  return pVdbeFunc->apAux[iArg].pAux;
+
+  return (pAuxData ? pAuxData->pAux : 0);
 }
 
 /*
@@ -602,29 +610,30 @@ void sqlite3_set_auxdata(
   void *pAux, 
   void (*xDelete)(void*)
 ){
-  struct AuxData *pAuxData;
-  VdbeFunc *pVdbeFunc;
-  if( iArg<0 ) goto failed;
+  AuxData *pAuxData;
+  Vdbe *pVdbe = pCtx->pVdbe;
 
   assert( sqlite3_mutex_held(pCtx->s.db->mutex) );
-  pVdbeFunc = pCtx->pVdbeFunc;
-  if( !pVdbeFunc || pVdbeFunc->nAux<=iArg ){
-    int nAux = (pVdbeFunc ? pVdbeFunc->nAux : 0);
-    int nMalloc = sizeof(VdbeFunc) + sizeof(struct AuxData)*iArg;
-    pVdbeFunc = sqlite3DbRealloc(pCtx->s.db, pVdbeFunc, nMalloc);
-    if( !pVdbeFunc ){
-      goto failed;
-    }
-    pCtx->pVdbeFunc = pVdbeFunc;
-    memset(&pVdbeFunc->apAux[nAux], 0, sizeof(struct AuxData)*(iArg+1-nAux));
-    pVdbeFunc->nAux = iArg+1;
-    pVdbeFunc->pFunc = pCtx->pFunc;
-  }
+  if( iArg<0 ) goto failed;
 
-  pAuxData = &pVdbeFunc->apAux[iArg];
-  if( pAuxData->pAux && pAuxData->xDelete ){
+  for(pAuxData=pVdbe->pAuxData; pAuxData; pAuxData=pAuxData->pNext){
+    if( pAuxData->iOp==pCtx->iOp && pAuxData->iArg==iArg ) break;
+  }
+  if( pAuxData==0 ){
+    pAuxData = sqlite3DbMallocZero(pVdbe->db, sizeof(AuxData));
+    if( !pAuxData ) goto failed;
+    pAuxData->iOp = pCtx->iOp;
+    pAuxData->iArg = iArg;
+    pAuxData->pNext = pVdbe->pAuxData;
+    pVdbe->pAuxData = pAuxData;
+    if( pCtx->fErrorOrAux==0 ){
+      pCtx->isError = 0;
+      pCtx->fErrorOrAux = 1;
+    }
+  }else if( pAuxData->xDelete ){
     pAuxData->xDelete(pAuxData->pAux);
   }
+
   pAuxData->pAux = pAux;
   pAuxData->xDelete = xDelete;
   return;
@@ -813,13 +822,6 @@ int sqlite3_column_type(sqlite3_stmt *pStmt, int i){
   return iType;
 }
 
-/* The following function is experimental and subject to change or
-** removal */
-/*int sqlite3_column_numeric_type(sqlite3_stmt *pStmt, int i){
-**  return sqlite3_value_numeric_type( columnMem(pStmt,i) );
-**}
-*/
-
 /*
 ** Convert the N-th element of pStmt->pColName[] into a string using
 ** xFunc() then return that string.  If N is out of range, return 0.
@@ -1296,7 +1298,7 @@ sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt){
 */
 int sqlite3_stmt_status(sqlite3_stmt *pStmt, int op, int resetFlag){
   Vdbe *pVdbe = (Vdbe*)pStmt;
-  int v = pVdbe->aCounter[op-1];
-  if( resetFlag ) pVdbe->aCounter[op-1] = 0;
-  return v;
+  u32 v = pVdbe->aCounter[op];
+  if( resetFlag ) pVdbe->aCounter[op] = 0;
+  return (int)v;
 }
diff --git a/lib/libsqlite3/src/vdbeaux.c b/lib/libsqlite3/src/vdbeaux.c
index 2c4269a59e6..ec071606a2e 100644
--- a/lib/libsqlite3/src/vdbeaux.c
+++ b/lib/libsqlite3/src/vdbeaux.c
@@ -250,8 +250,8 @@ int sqlite3VdbeMakeLabel(Vdbe *p){
 void sqlite3VdbeResolveLabel(Vdbe *p, int x){
   int j = -1-x;
   assert( p->magic==VDBE_MAGIC_INIT );
-  assert( j>=0 && j<p->nLabel );
-  if( p->aLabel ){
+  assert( j<p->nLabel );
+  if( j>=0 && p->aLabel ){
     p->aLabel[j] = p->nOp;
   }
 }
@@ -403,32 +403,64 @@ static void resolveP2Values(Vdbe *p, int *pMaxFuncArgs){
   Op *pOp;
   int *aLabel = p->aLabel;
   p->readOnly = 1;
+  p->bIsReader = 0;
   for(pOp=p->aOp, i=p->nOp-1; i>=0; i--, pOp++){
     u8 opcode = pOp->opcode;
 
-    pOp->opflags = sqlite3OpcodeProperty[opcode];
-    if( opcode==OP_Function || opcode==OP_AggStep ){
-      if( pOp->p5>nMaxArgs ) nMaxArgs = pOp->p5;
-    }else if( (opcode==OP_Transaction && pOp->p2!=0) || opcode==OP_Vacuum ){
-      p->readOnly = 0;
+    /* NOTE: Be sure to update mkopcodeh.awk when adding or removing
+    ** cases from this switch! */
+    switch( opcode ){
+      case OP_Function:
+      case OP_AggStep: {
+        if( pOp->p5>nMaxArgs ) nMaxArgs = pOp->p5;
+        break;
+      }
+      case OP_Transaction: {
+        if( pOp->p2!=0 ) p->readOnly = 0;
+        /* fall thru */
+      }
+      case OP_AutoCommit:
+      case OP_Savepoint: {
+        p->bIsReader = 1;
+        break;
+      }
+#ifndef SQLITE_OMIT_WAL
+      case OP_Checkpoint:
+#endif
+      case OP_Vacuum:
+      case OP_JournalMode: {
+        p->readOnly = 0;
+        p->bIsReader = 1;
+        break;
+      }
 #ifndef SQLITE_OMIT_VIRTUALTABLE
-    }else if( opcode==OP_VUpdate ){
-      if( pOp->p2>nMaxArgs ) nMaxArgs = pOp->p2;
-    }else if( opcode==OP_VFilter ){
-      int n;
-      assert( p->nOp - i >= 3 );
-      assert( pOp[-1].opcode==OP_Integer );
-      n = pOp[-1].p1;
-      if( n>nMaxArgs ) nMaxArgs = n;
+      case OP_VUpdate: {
+        if( pOp->p2>nMaxArgs ) nMaxArgs = pOp->p2;
+        break;
+      }
+      case OP_VFilter: {
+        int n;
+        assert( p->nOp - i >= 3 );
+        assert( pOp[-1].opcode==OP_Integer );
+        n = pOp[-1].p1;
+        if( n>nMaxArgs ) nMaxArgs = n;
+        break;
+      }
 #endif
-    }else if( opcode==OP_Next || opcode==OP_SorterNext ){
-      pOp->p4.xAdvance = sqlite3BtreeNext;
-      pOp->p4type = P4_ADVANCE;
-    }else if( opcode==OP_Prev ){
-      pOp->p4.xAdvance = sqlite3BtreePrevious;
-      pOp->p4type = P4_ADVANCE;
+      case OP_Next:
+      case OP_SorterNext: {
+        pOp->p4.xAdvance = sqlite3BtreeNext;
+        pOp->p4type = P4_ADVANCE;
+        break;
+      }
+      case OP_Prev: {
+        pOp->p4.xAdvance = sqlite3BtreePrevious;
+        pOp->p4type = P4_ADVANCE;
+        break;
+      }
     }
 
+    pOp->opflags = sqlite3OpcodeProperty[opcode];
     if( (pOp->opflags & OPFLG_JUMP)!=0 && pOp->p2<0 ){
       assert( -1-pOp->p2<p->nLabel );
       pOp->p2 = aLabel[-1-pOp->p2];
@@ -436,8 +468,8 @@ static void resolveP2Values(Vdbe *p, int *pMaxFuncArgs){
   }
   sqlite3DbFree(p->db, p->aLabel);
   p->aLabel = 0;
-
   *pMaxFuncArgs = nMaxArgs;
+  assert( p->bIsReader!=0 || p->btreeMask==0 );
 }
 
 /*
@@ -563,8 +595,7 @@ void sqlite3VdbeChangeP5(Vdbe *p, u8 val){
 ** the address of the next instruction to be coded.
 */
 void sqlite3VdbeJumpHere(Vdbe *p, int addr){
-  assert( addr>=0 || p->db->mallocFailed );
-  if( addr>=0 ) sqlite3VdbeChangeP2(p, addr, p->nOp);
+  if( ALWAYS(addr>=0) ) sqlite3VdbeChangeP2(p, addr, p->nOp);
 }
 
 
@@ -600,13 +631,6 @@ static void freeP4(sqlite3 *db, int p4type, void *p4){
         if( db->pnBytesFreed==0 ) sqlite3_free(p4);
         break;
       }
-      case P4_VDBEFUNC: {
-        VdbeFunc *pVdbeFunc = (VdbeFunc *)p4;
-        freeEphemeralFunction(db, pVdbeFunc->pFunc);
-        if( db->pnBytesFreed==0 ) sqlite3VdbeDeleteAuxData(pVdbeFunc, 0);
-        sqlite3DbFree(db, pVdbeFunc);
-        break;
-      }
       case P4_FUNCDEF: {
         freeEphemeralFunction(db, (FuncDef*)p4);
         break;
@@ -725,20 +749,13 @@ void sqlite3VdbeChangeP4(Vdbe *p, int addr, const char *zP4, int n){
     pOp->p4.p = 0;
     pOp->p4type = P4_NOTUSED;
   }else if( n==P4_KEYINFO ){
-    KeyInfo *pKeyInfo;
-    int nField, nByte;
-
-    nField = ((KeyInfo*)zP4)->nField;
-    nByte = sizeof(*pKeyInfo) + (nField-1)*sizeof(pKeyInfo->aColl[0]) + nField;
-    pKeyInfo = sqlite3DbMallocRaw(0, nByte);
-    pOp->p4.pKeyInfo = pKeyInfo;
-    if( pKeyInfo ){
-      u8 *aSortOrder;
-      memcpy((char*)pKeyInfo, zP4, nByte - nField);
-      aSortOrder = pKeyInfo->aSortOrder;
-      assert( aSortOrder!=0 );
-      pKeyInfo->aSortOrder = (unsigned char*)&pKeyInfo->aColl[nField];
-      memcpy(pKeyInfo->aSortOrder, aSortOrder, nField);
+    KeyInfo *pOrig, *pNew;
+
+    pOrig = (KeyInfo*)zP4;
+    pOp->p4.pKeyInfo = pNew = sqlite3KeyInfoAlloc(db, pOrig->nField);
+    if( pNew ){
+      memcpy(pNew->aColl, pOrig->aColl, pOrig->nField*sizeof(pNew->aColl[0]));
+      memcpy(pNew->aSortOrder, pOrig->aSortOrder, pOrig->nField);
       pOp->p4type = P4_KEYINFO;
     }else{
       p->db->mallocFailed = 1;
@@ -1636,6 +1653,10 @@ static void closeAllCursors(Vdbe *p){
     p->pDelFrame = pDel->pParent;
     sqlite3VdbeFrameDelete(pDel);
   }
+
+  /* Delete any auxdata allocations made by the VM */
+  sqlite3VdbeDeleteAuxData(p, -1, 0);
+  assert( p->pAuxData==0 );
 }
 
 /*
@@ -1744,7 +1765,7 @@ static int vdbeCommit(sqlite3 *db, Vdbe *p){
   ** required, as an xSync() callback may add an attached database
   ** to the transaction.
   */
-  rc = sqlite3VtabSync(db, &p->zErrMsg);
+  rc = sqlite3VtabSync(db, p);
 
   /* This loop determines (a) if the commit hook should be invoked and
   ** (b) how many database files have open write transactions, not 
@@ -1963,7 +1984,7 @@ static int vdbeCommit(sqlite3 *db, Vdbe *p){
 }
 
 /* 
-** This routine checks that the sqlite3.activeVdbeCnt count variable
+** This routine checks that the sqlite3.nVdbeActive count variable
 ** matches the number of vdbe's in the list sqlite3.pVdbe that are
 ** currently active. An assertion fails if the two counts do not match.
 ** This is an internal self-check only - it is not an essential processing
@@ -1976,16 +1997,19 @@ static void checkActiveVdbeCnt(sqlite3 *db){
   Vdbe *p;
   int cnt = 0;
   int nWrite = 0;
+  int nRead = 0;
   p = db->pVdbe;
   while( p ){
     if( p->magic==VDBE_MAGIC_RUN && p->pc>=0 ){
       cnt++;
       if( p->readOnly==0 ) nWrite++;
+      if( p->bIsReader ) nRead++;
     }
     p = p->pNext;
   }
-  assert( cnt==db->activeVdbeCnt );
-  assert( nWrite==db->writeVdbeCnt );
+  assert( cnt==db->nVdbeActive );
+  assert( nWrite==db->nVdbeWrite );
+  assert( nRead==db->nVdbeRead );
 }
 #else
 #define checkActiveVdbeCnt(x)
@@ -1996,7 +2020,7 @@ static void checkActiveVdbeCnt(sqlite3 *db){
 ** close it now. Argument eOp must be either SAVEPOINT_ROLLBACK or
 ** SAVEPOINT_RELEASE. If it is SAVEPOINT_ROLLBACK, then the statement
 ** transaction is rolled back. If eOp is SAVEPOINT_RELEASE, then the 
-** statement transaction is commtted.
+** statement transaction is committed.
 **
 ** If an IO error occurs, an SQLITE_IOERR_XXX error code is returned. 
 ** Otherwise SQLITE_OK.
@@ -2050,6 +2074,7 @@ int sqlite3VdbeCloseStatement(Vdbe *p, int eOp){
     ** the statement transaction was opened.  */
     if( eOp==SAVEPOINT_ROLLBACK ){
       db->nDeferredCons = p->nStmtDefCons;
+      db->nDeferredImmCons = p->nStmtDefImmCons;
     }
   }
   return rc;
@@ -2068,7 +2093,9 @@ int sqlite3VdbeCloseStatement(Vdbe *p, int eOp){
 #ifndef SQLITE_OMIT_FOREIGN_KEY
 int sqlite3VdbeCheckFk(Vdbe *p, int deferred){
   sqlite3 *db = p->db;
-  if( (deferred && db->nDeferredCons>0) || (!deferred && p->nFkConstraint>0) ){
+  if( (deferred && (db->nDeferredCons+db->nDeferredImmCons)>0) 
+   || (!deferred && p->nFkConstraint>0) 
+  ){
     p->rc = SQLITE_CONSTRAINT_FOREIGNKEY;
     p->errorAction = OE_Abort;
     sqlite3SetString(&p->zErrMsg, db, "foreign key constraint failed");
@@ -2121,8 +2148,9 @@ int sqlite3VdbeHalt(Vdbe *p){
   }
   checkActiveVdbeCnt(db);
 
-  /* No commit or rollback needed if the program never started */
-  if( p->pc>=0 ){
+  /* No commit or rollback needed if the program never started or if the
+  ** SQL statement does not read or write a database file.  */
+  if( p->pc>=0 && p->bIsReader ){
     int mrc;   /* Primary error code from p->rc */
     int eStatementOp = 0;
     int isSpecialError;            /* Set to true if a 'special' error */
@@ -2175,7 +2203,7 @@ int sqlite3VdbeHalt(Vdbe *p){
     */
     if( !sqlite3VtabInSync(db) 
      && db->autoCommit 
-     && db->writeVdbeCnt==(p->readOnly==0) 
+     && db->nVdbeWrite==(p->readOnly==0) 
     ){
       if( p->rc==SQLITE_OK || (p->errorAction==OE_Fail && !isSpecialError) ){
         rc = sqlite3VdbeCheckFk(p, 1);
@@ -2200,6 +2228,8 @@ int sqlite3VdbeHalt(Vdbe *p){
           sqlite3RollbackAll(db, SQLITE_OK);
         }else{
           db->nDeferredCons = 0;
+          db->nDeferredImmCons = 0;
+          db->flags &= ~SQLITE_DeferFKs;
           sqlite3CommitInternalChanges(db);
         }
       }else{
@@ -2256,11 +2286,12 @@ int sqlite3VdbeHalt(Vdbe *p){
 
   /* We have successfully halted and closed the VM.  Record this fact. */
   if( p->pc>=0 ){
-    db->activeVdbeCnt--;
-    if( !p->readOnly ){
-      db->writeVdbeCnt--;
-    }
-    assert( db->activeVdbeCnt>=db->writeVdbeCnt );
+    db->nVdbeActive--;
+    if( !p->readOnly ) db->nVdbeWrite--;
+    if( p->bIsReader ) db->nVdbeRead--;
+    assert( db->nVdbeActive>=db->nVdbeRead );
+    assert( db->nVdbeRead>=db->nVdbeWrite );
+    assert( db->nVdbeWrite>=0 );
   }
   p->magic = VDBE_MAGIC_HALT;
   checkActiveVdbeCnt(db);
@@ -2276,7 +2307,7 @@ int sqlite3VdbeHalt(Vdbe *p){
     sqlite3ConnectionUnlocked(db);
   }
 
-  assert( db->activeVdbeCnt>0 || db->autoCommit==0 || db->nStatement==0 );
+  assert( db->nVdbeActive>0 || db->autoCommit==0 || db->nStatement==0 );
   return (p->rc==SQLITE_BUSY ? SQLITE_BUSY : SQLITE_OK);
 }
 
@@ -2424,20 +2455,35 @@ int sqlite3VdbeFinalize(Vdbe *p){
 }
 
 /*
-** Call the destructor for each auxdata entry in pVdbeFunc for which
-** the corresponding bit in mask is clear.  Auxdata entries beyond 31
-** are always destroyed.  To destroy all auxdata entries, call this
-** routine with mask==0.
+** If parameter iOp is less than zero, then invoke the destructor for
+** all auxiliary data pointers currently cached by the VM passed as
+** the first argument.
+**
+** Or, if iOp is greater than or equal to zero, then the destructor is
+** only invoked for those auxiliary data pointers created by the user 
+** function invoked by the OP_Function opcode at instruction iOp of 
+** VM pVdbe, and only then if:
+**
+**    * the associated function parameter is the 32nd or later (counting
+**      from left to right), or
+**
+**    * the corresponding bit in argument mask is clear (where the first
+**      function parameter corrsponds to bit 0 etc.).
 */
-void sqlite3VdbeDeleteAuxData(VdbeFunc *pVdbeFunc, int mask){
-  int i;
-  for(i=0; i<pVdbeFunc->nAux; i++){
-    struct AuxData *pAux = &pVdbeFunc->apAux[i];
-    if( (i>31 || !(mask&(((u32)1)<<i))) && pAux->pAux ){
+void sqlite3VdbeDeleteAuxData(Vdbe *pVdbe, int iOp, int mask){
+  AuxData **pp = &pVdbe->pAuxData;
+  while( *pp ){
+    AuxData *pAux = *pp;
+    if( (iOp<0)
+     || (pAux->iOp==iOp && (pAux->iArg>31 || !(mask & ((u32)1<<pAux->iArg))))
+    ){
       if( pAux->xDelete ){
         pAux->xDelete(pAux->pAux);
       }
-      pAux->pAux = 0;
+      *pp = pAux->pNext;
+      sqlite3DbFree(pVdbe->db, pAux);
+    }else{
+      pp= &pAux->pNext;
     }
   }
 }
@@ -2956,11 +3002,10 @@ int sqlite3VdbeRecordCompare(
   int nKey1, const void *pKey1, /* Left key */
   UnpackedRecord *pPKey2        /* Right key */
 ){
-  int d1;            /* Offset into aKey[] of next data element */
+  u32 d1;            /* Offset into aKey[] of next data element */
   u32 idx1;          /* Offset into aKey[] of next header element */
   u32 szHdr1;        /* Number of bytes in header */
   int i = 0;
-  int nField;
   int rc = 0;
   const unsigned char *aKey1 = (const unsigned char *)pKey1;
   KeyInfo *pKeyInfo;
@@ -2983,14 +3028,25 @@ int sqlite3VdbeRecordCompare(
   
   idx1 = getVarint32(aKey1, szHdr1);
   d1 = szHdr1;
-  nField = pKeyInfo->nField;
+  assert( pKeyInfo->nField+1>=pPKey2->nField );
   assert( pKeyInfo->aSortOrder!=0 );
   while( idx1<szHdr1 && i<pPKey2->nField ){
     u32 serial_type1;
 
     /* Read the serial types for the next element in each key. */
     idx1 += getVarint32( aKey1+idx1, serial_type1 );
-    if( d1>=nKey1 && sqlite3VdbeSerialTypeLen(serial_type1)>0 ) break;
+
+    /* Verify that there is enough key space remaining to avoid
+    ** a buffer overread.  The "d1+serial_type1+2" subexpression will
+    ** always be greater than or equal to the amount of required key space.
+    ** Use that approximation to avoid the more expensive call to
+    ** sqlite3VdbeSerialTypeLen() in the common case.
+    */
+    if( d1+serial_type1+2>(u32)nKey1
+     && d1+sqlite3VdbeSerialTypeLen(serial_type1)>(u32)nKey1 
+    ){
+      break;
+    }
 
     /* Extract the values to be compared.
     */
@@ -2998,13 +3054,12 @@ int sqlite3VdbeRecordCompare(
 
     /* Do the comparison
     */
-    rc = sqlite3MemCompare(&mem1, &pPKey2->aMem[i],
-                           i<nField ? pKeyInfo->aColl[i] : 0);
+    rc = sqlite3MemCompare(&mem1, &pPKey2->aMem[i], pKeyInfo->aColl[i]);
     if( rc!=0 ){
       assert( mem1.zMalloc==0 );  /* See comment below */
 
       /* Invert the result if we are using DESC sort order. */
-      if( i<nField && pKeyInfo->aSortOrder[i] ){
+      if( pKeyInfo->aSortOrder[i] ){
         rc = -rc;
       }
     
@@ -3219,7 +3274,7 @@ sqlite3 *sqlite3VdbeDb(Vdbe *v){
 **
 ** The returned value must be freed by the caller using sqlite3ValueFree().
 */
-sqlite3_value *sqlite3VdbeGetValue(Vdbe *v, int iVar, u8 aff){
+sqlite3_value *sqlite3VdbeGetBoundValue(Vdbe *v, int iVar, u8 aff){
   assert( iVar>0 );
   if( v ){
     Mem *pMem = &v->aVar[iVar-1];
@@ -3249,3 +3304,18 @@ void sqlite3VdbeSetVarmask(Vdbe *v, int iVar){
     v->expmask |= ((u32)1 << (iVar-1));
   }
 }
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/*
+** Transfer error message text from an sqlite3_vtab.zErrMsg (text stored
+** in memory obtained from sqlite3_malloc) into a Vdbe.zErrMsg (text stored
+** in memory obtained from sqlite3DbMalloc).
+*/
+void sqlite3VtabImportErrmsg(Vdbe *p, sqlite3_vtab *pVtab){
+  sqlite3 *db = p->db;
+  sqlite3DbFree(db, p->zErrMsg);
+  p->zErrMsg = sqlite3DbStrDup(db, pVtab->zErrMsg);
+  sqlite3_free(pVtab->zErrMsg);
+  pVtab->zErrMsg = 0;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
diff --git a/lib/libsqlite3/src/vdbemem.c b/lib/libsqlite3/src/vdbemem.c
index 8fc222e2de2..0fa51e8ae1a 100644
--- a/lib/libsqlite3/src/vdbemem.c
+++ b/lib/libsqlite3/src/vdbemem.c
@@ -799,34 +799,29 @@ int sqlite3MemCompare(const Mem *pMem1, const Mem *pMem2, const CollSeq *pColl){
   ** if both values are integers.
   */
   if( combined_flags&(MEM_Int|MEM_Real) ){
-    if( !(f1&(MEM_Int|MEM_Real)) ){
-      return 1;
-    }
-    if( !(f2&(MEM_Int|MEM_Real)) ){
-      return -1;
-    }
-    if( (f1 & f2 & MEM_Int)==0 ){
-      double r1, r2;
-      if( (f1&MEM_Real)==0 ){
-        r1 = (double)pMem1->u.i;
-      }else{
-        r1 = pMem1->r;
-      }
-      if( (f2&MEM_Real)==0 ){
-        r2 = (double)pMem2->u.i;
-      }else{
-        r2 = pMem2->r;
-      }
-      if( r1<r2 ) return -1;
-      if( r1>r2 ) return 1;
-      return 0;
-    }else{
-      assert( f1&MEM_Int );
-      assert( f2&MEM_Int );
+    double r1, r2;
+    if( (f1 & f2 & MEM_Int)!=0 ){
       if( pMem1->u.i < pMem2->u.i ) return -1;
       if( pMem1->u.i > pMem2->u.i ) return 1;
       return 0;
     }
+    if( (f1&MEM_Real)!=0 ){
+      r1 = pMem1->r;
+    }else if( (f1&MEM_Int)!=0 ){
+      r1 = (double)pMem1->u.i;
+    }else{
+      return 1;
+    }
+    if( (f2&MEM_Real)!=0 ){
+      r2 = pMem2->r;
+    }else if( (f2&MEM_Int)!=0 ){
+      r2 = (double)pMem2->u.i;
+    }else{
+      return -1;
+    }
+    if( r1<r2 ) return -1;
+    if( r1>r2 ) return 1;
+    return 0;
   }
 
   /* If one value is a string and the other is a blob, the string is less.
diff --git a/lib/libsqlite3/src/vdbesort.c b/lib/libsqlite3/src/vdbesort.c
index fdfc4a79ddc..c8709bdafd8 100644
--- a/lib/libsqlite3/src/vdbesort.c
+++ b/lib/libsqlite3/src/vdbesort.c
@@ -54,7 +54,7 @@ typedef struct FileWriter FileWriter;
 ** other key value. If the keys are equal (only possible with two EOF
 ** values), it doesn't matter which index is stored.
 **
-** The (N/4) elements of aTree[] that preceed the final (N/2) described 
+** The (N/4) elements of aTree[] that precede the final (N/2) described 
 ** above contains the index of the smallest of each block of 4 iterators.
 ** And so on. So that aTree[1] contains the index of the iterator that 
 ** currently points to the smallest key value. aTree[0] is unused.
diff --git a/lib/libsqlite3/src/vdbetrace.c b/lib/libsqlite3/src/vdbetrace.c
index 356277e8d23..0a767261f07 100644
--- a/lib/libsqlite3/src/vdbetrace.c
+++ b/lib/libsqlite3/src/vdbetrace.c
@@ -47,9 +47,9 @@ static int findNextHostParameter(const char *zSql, int *pnToken){
 
 /*
 ** This function returns a pointer to a nul-terminated string in memory
-** obtained from sqlite3DbMalloc(). If sqlite3.vdbeExecCnt is 1, then the
+** obtained from sqlite3DbMalloc(). If sqlite3.nVdbeExec is 1, then the
 ** string contains a copy of zRawSql but with host parameters expanded to 
-** their current bindings. Or, if sqlite3.vdbeExecCnt is greater than 1, 
+** their current bindings. Or, if sqlite3.nVdbeExec is greater than 1, 
 ** then the returned string holds a copy of zRawSql with "-- " prepended
 ** to each line of text.
 **
@@ -87,7 +87,7 @@ char *sqlite3VdbeExpandSql(
   sqlite3StrAccumInit(&out, zBase, sizeof(zBase), 
                       db->aLimit[SQLITE_LIMIT_LENGTH]);
   out.db = db;
-  if( db->vdbeExecCnt>1 ){
+  if( db->nVdbeExec>1 ){
     while( *zRawSql ){
       const char *zStart = zRawSql;
       while( *(zRawSql++)!='\n' && *zRawSql );
diff --git a/lib/libsqlite3/src/vtab.c b/lib/libsqlite3/src/vtab.c
index 958202c31e2..357a6dba2a2 100644
--- a/lib/libsqlite3/src/vtab.c
+++ b/lib/libsqlite3/src/vtab.c
@@ -810,10 +810,9 @@ static void callFinaliser(sqlite3 *db, int offset){
 ** array. Return the error code for the first error that occurs, or
 ** SQLITE_OK if all xSync operations are successful.
 **
-** Set *pzErrmsg to point to a buffer that should be released using 
-** sqlite3DbFree() containing an error message, if one is available.
+** If an error message is available, leave it in p->zErrMsg.
 */
-int sqlite3VtabSync(sqlite3 *db, char **pzErrmsg){
+int sqlite3VtabSync(sqlite3 *db, Vdbe *p){
   int i;
   int rc = SQLITE_OK;
   VTable **aVTrans = db->aVTrans;
@@ -824,9 +823,7 @@ int sqlite3VtabSync(sqlite3 *db, char **pzErrmsg){
     sqlite3_vtab *pVtab = aVTrans[i]->pVtab;
     if( pVtab && (x = pVtab->pModule->xSync)!=0 ){
       rc = x(pVtab);
-      sqlite3DbFree(db, *pzErrmsg);
-      *pzErrmsg = sqlite3DbStrDup(db, pVtab->zErrMsg);
-      sqlite3_free(pVtab->zErrMsg);
+      sqlite3VtabImportErrmsg(p, pVtab);
     }
   }
   db->aVTrans = aVTrans;
diff --git a/lib/libsqlite3/src/wal.c b/lib/libsqlite3/src/wal.c
index e642ea2105b..f4139206481 100644
--- a/lib/libsqlite3/src/wal.c
+++ b/lib/libsqlite3/src/wal.c
@@ -2463,7 +2463,7 @@ int sqlite3WalBeginWriteTransaction(Wal *pWal){
   if( memcmp(&pWal->hdr, (void *)walIndexHdr(pWal), sizeof(WalIndexHdr))!=0 ){
     walUnlockExclusive(pWal, WAL_WRITE_LOCK, 1);
     pWal->writeLock = 0;
-    rc = SQLITE_BUSY;
+    rc = SQLITE_BUSY_SNAPSHOT;
   }
 
   return rc;
diff --git a/lib/libsqlite3/src/where.c b/lib/libsqlite3/src/where.c
index e614f4a6d86..aad522f758c 100644
--- a/lib/libsqlite3/src/where.c
+++ b/lib/libsqlite3/src/where.c
@@ -27,18 +27,186 @@
 #endif
 #if defined(SQLITE_DEBUG) \
     && (defined(SQLITE_TEST) || defined(SQLITE_ENABLE_WHERETRACE))
-# define WHERETRACE(X)  if(sqlite3WhereTrace) sqlite3DebugPrintf X
+# define WHERETRACE(K,X)  if(sqlite3WhereTrace&(K)) sqlite3DebugPrintf X
+# define WHERETRACE_ENABLED 1
 #else
-# define WHERETRACE(X)
+# define WHERETRACE(K,X)
 #endif
 
-/* Forward reference
+/* Forward references
 */
 typedef struct WhereClause WhereClause;
 typedef struct WhereMaskSet WhereMaskSet;
 typedef struct WhereOrInfo WhereOrInfo;
 typedef struct WhereAndInfo WhereAndInfo;
-typedef struct WhereCost WhereCost;
+typedef struct WhereLevel WhereLevel;
+typedef struct WhereLoop WhereLoop;
+typedef struct WherePath WherePath;
+typedef struct WhereTerm WhereTerm;
+typedef struct WhereLoopBuilder WhereLoopBuilder;
+typedef struct WhereScan WhereScan;
+typedef struct WhereOrCost WhereOrCost;
+typedef struct WhereOrSet WhereOrSet;
+
+/*
+** Cost X is tracked as 10*log2(X) stored in a 16-bit integer.  The
+** maximum cost for ordinary tables is 64*(2**63) which becomes 6900.
+** (Virtual tables can return a larger cost, but let's assume they do not.)
+** So all costs can be stored in a 16-bit unsigned integer without risk
+** of overflow.
+**
+** Costs are estimates, so no effort is made to compute 10*log2(X) exactly.
+** Instead, a close estimate is used.  Any value of X<=1 is stored as 0.
+** X=2 is 10.  X=3 is 16.  X=1000 is 99. etc.
+**
+** The tool/wherecosttest.c source file implements a command-line program
+** that will convert WhereCosts to integers, convert integers to WhereCosts
+** and do addition and multiplication on WhereCost values.  The wherecosttest
+** command-line program is a useful utility to have around when working with
+** this module.
+*/
+typedef unsigned short int WhereCost;
+
+/*
+** This object contains information needed to implement a single nested
+** loop in WHERE clause.
+**
+** Contrast this object with WhereLoop.  This object describes the
+** implementation of the loop.  WhereLoop describes the algorithm.
+** This object contains a pointer to the WhereLoop algorithm as one of
+** its elements.
+**
+** The WhereInfo object contains a single instance of this object for
+** each term in the FROM clause (which is to say, for each of the
+** nested loops as implemented).  The order of WhereLevel objects determines
+** the loop nested order, with WhereInfo.a[0] being the outer loop and
+** WhereInfo.a[WhereInfo.nLevel-1] being the inner loop.
+*/
+struct WhereLevel {
+  int iLeftJoin;        /* Memory cell used to implement LEFT OUTER JOIN */
+  int iTabCur;          /* The VDBE cursor used to access the table */
+  int iIdxCur;          /* The VDBE cursor used to access pIdx */
+  int addrBrk;          /* Jump here to break out of the loop */
+  int addrNxt;          /* Jump here to start the next IN combination */
+  int addrCont;         /* Jump here to continue with the next loop cycle */
+  int addrFirst;        /* First instruction of interior of the loop */
+  int addrBody;         /* Beginning of the body of this loop */
+  u8 iFrom;             /* Which entry in the FROM clause */
+  u8 op, p5;            /* Opcode and P5 of the opcode that ends the loop */
+  int p1, p2;           /* Operands of the opcode used to ends the loop */
+  union {               /* Information that depends on pWLoop->wsFlags */
+    struct {
+      int nIn;              /* Number of entries in aInLoop[] */
+      struct InLoop {
+        int iCur;              /* The VDBE cursor used by this IN operator */
+        int addrInTop;         /* Top of the IN loop */
+        u8 eEndLoopOp;         /* IN Loop terminator. OP_Next or OP_Prev */
+      } *aInLoop;           /* Information about each nested IN operator */
+    } in;                 /* Used when pWLoop->wsFlags&WHERE_IN_ABLE */
+    Index *pCovidx;       /* Possible covering index for WHERE_MULTI_OR */
+  } u;
+  struct WhereLoop *pWLoop;  /* The selected WhereLoop object */
+};
+
+/*
+** Each instance of this object represents an algorithm for evaluating one
+** term of a join.  Every term of the FROM clause will have at least
+** one corresponding WhereLoop object (unless INDEXED BY constraints
+** prevent a query solution - which is an error) and many terms of the
+** FROM clause will have multiple WhereLoop objects, each describing a
+** potential way of implementing that FROM-clause term, together with
+** dependencies and cost estimates for using the chosen algorithm.
+**
+** Query planning consists of building up a collection of these WhereLoop
+** objects, then computing a particular sequence of WhereLoop objects, with
+** one WhereLoop object per FROM clause term, that satisfy all dependencies
+** and that minimize the overall cost.
+*/
+struct WhereLoop {
+  Bitmask prereq;       /* Bitmask of other loops that must run first */
+  Bitmask maskSelf;     /* Bitmask identifying table iTab */
+#ifdef SQLITE_DEBUG
+  char cId;             /* Symbolic ID of this loop for debugging use */
+#endif
+  u8 iTab;              /* Position in FROM clause of table for this loop */
+  u8 iSortIdx;          /* Sorting index number.  0==None */
+  WhereCost rSetup;     /* One-time setup cost (ex: create transient index) */
+  WhereCost rRun;       /* Cost of running each loop */
+  WhereCost nOut;       /* Estimated number of output rows */
+  union {
+    struct {               /* Information for internal btree tables */
+      int nEq;               /* Number of equality constraints */
+      Index *pIndex;         /* Index used, or NULL */
+    } btree;
+    struct {               /* Information for virtual tables */
+      int idxNum;            /* Index number */
+      u8 needFree;           /* True if sqlite3_free(idxStr) is needed */
+      u8 isOrdered;          /* True if satisfies ORDER BY */
+      u16 omitMask;          /* Terms that may be omitted */
+      char *idxStr;          /* Index identifier string */
+    } vtab;
+  } u;
+  u32 wsFlags;          /* WHERE_* flags describing the plan */
+  u16 nLTerm;           /* Number of entries in aLTerm[] */
+  /**** whereLoopXfer() copies fields above ***********************/
+# define WHERE_LOOP_XFER_SZ offsetof(WhereLoop,nLSlot)
+  u16 nLSlot;           /* Number of slots allocated for aLTerm[] */
+  WhereTerm **aLTerm;   /* WhereTerms used */
+  WhereLoop *pNextLoop; /* Next WhereLoop object in the WhereClause */
+  WhereTerm *aLTermSpace[4];  /* Initial aLTerm[] space */
+};
+
+/* This object holds the prerequisites and the cost of running a
+** subquery on one operand of an OR operator in the WHERE clause.
+** See WhereOrSet for additional information 
+*/
+struct WhereOrCost {
+  Bitmask prereq;     /* Prerequisites */
+  WhereCost rRun;     /* Cost of running this subquery */
+  WhereCost nOut;     /* Number of outputs for this subquery */
+};
+
+/* The WhereOrSet object holds a set of possible WhereOrCosts that
+** correspond to the subquery(s) of OR-clause processing.  Only the
+** best N_OR_COST elements are retained.
+*/
+#define N_OR_COST 3
+struct WhereOrSet {
+  u16 n;                      /* Number of valid a[] entries */
+  WhereOrCost a[N_OR_COST];   /* Set of best costs */
+};
+
+
+/* Forward declaration of methods */
+static int whereLoopResize(sqlite3*, WhereLoop*, int);
+
+/*
+** Each instance of this object holds a sequence of WhereLoop objects
+** that implement some or all of a query plan.
+**
+** Think of each WhereLoop object as a node in a graph with arcs
+** showing dependences and costs for travelling between nodes.  (That is
+** not a completely accurate description because WhereLoop costs are a
+** vector, not a scalar, and because dependences are many-to-one, not
+** one-to-one as are graph nodes.  But it is a useful visualization aid.)
+** Then a WherePath object is a path through the graph that visits some
+** or all of the WhereLoop objects once.
+**
+** The "solver" works by creating the N best WherePath objects of length
+** 1.  Then using those as a basis to compute the N best WherePath objects
+** of length 2.  And so forth until the length of WherePaths equals the
+** number of nodes in the FROM clause.  The best (lowest cost) WherePath
+** at the end is the choosen query plan.
+*/
+struct WherePath {
+  Bitmask maskLoop;     /* Bitmask of all WhereLoop objects in this path */
+  Bitmask revLoop;      /* aLoop[]s that should be reversed for ORDER BY */
+  WhereCost nRow;       /* Estimated number of rows generated by this path */
+  WhereCost rCost;      /* Total cost of this path */
+  u8 isOrdered;         /* True if this path satisfies ORDER BY */
+  u8 isOrderedValid;    /* True if the isOrdered field is valid */
+  WhereLoop **aLoop;    /* Array of WhereLoop objects implementing this path */
+};
 
 /*
 ** The query generator uses an array of instances of this structure to
@@ -66,9 +234,9 @@ typedef struct WhereCost WhereCost;
 **
 **         (t1.X <op> <expr>) OR (t1.Y <op> <expr>) OR ....
 **
-** In this second case, wtFlag as the TERM_ORINFO set and eOperator==WO_OR
+** In this second case, wtFlag has the TERM_ORINFO bit set and eOperator==WO_OR
 ** and the WhereTerm.u.pOrInfo field points to auxiliary information that
-** is collected about the
+** is collected about the OR clause.
 **
 ** If a term in the WHERE clause does not match either of the two previous
 ** categories, then eOperator==0.  The WhereTerm.pExpr field is still set
@@ -91,7 +259,6 @@ typedef struct WhereCost WhereCost;
 ** in prereqRight and prereqAll.  The default is 64 bits, hence SQLite
 ** is only able to process joins with 64 or fewer tables.
 */
-typedef struct WhereTerm WhereTerm;
 struct WhereTerm {
   Expr *pExpr;            /* Pointer to the subexpression that is this term */
   int iParent;            /* Disable pWC->a[iParent] when this term disabled */
@@ -126,6 +293,22 @@ struct WhereTerm {
 #endif
 
 /*
+** An instance of the WhereScan object is used as an iterator for locating
+** terms in the WHERE clause that are useful to the query planner.
+*/
+struct WhereScan {
+  WhereClause *pOrigWC;      /* Original, innermost WhereClause */
+  WhereClause *pWC;          /* WhereClause currently being scanned */
+  char *zCollName;           /* Required collating sequence, if not NULL */
+  char idxaff;               /* Must match this affinity, if zCollName!=NULL */
+  unsigned char nEquiv;      /* Number of entries in aEquiv[] */
+  unsigned char iEquiv;      /* Next unused slot in aEquiv[] */
+  u32 opMask;                /* Acceptable operators */
+  int k;                     /* Resume scanning at this->pWC->a[this->k] */
+  int aEquiv[22];            /* Cursor,Column pairs for equivalence classes */
+};
+
+/*
 ** An instance of the following structure holds all information about a
 ** WHERE clause.  Mostly this is a container for one or more WhereTerms.
 **
@@ -138,11 +321,9 @@ struct WhereTerm {
 ** subclauses points to the WhereClause object for the whole clause.
 */
 struct WhereClause {
-  Parse *pParse;           /* The parser context */
-  WhereMaskSet *pMaskSet;  /* Mapping of table cursor numbers to bitmasks */
+  WhereInfo *pWInfo;       /* WHERE clause processing context */
   WhereClause *pOuter;     /* Outer conjunction */
   u8 op;                   /* Split operator.  TK_AND or TK_OR */
-  u16 wctrlFlags;          /* Might include WHERE_AND_ONLY */
   int nTerm;               /* Number of terms */
   int nSlot;               /* Number of entries in a[] */
   WhereTerm *a;            /* Each a[] describes a term of the WHERE cluase */
@@ -202,19 +383,55 @@ struct WhereMaskSet {
 };
 
 /*
-** A WhereCost object records a lookup strategy and the estimated
-** cost of pursuing that strategy.
+** This object is a convenience wrapper holding all information needed
+** to construct WhereLoop objects for a particular query.
+*/
+struct WhereLoopBuilder {
+  WhereInfo *pWInfo;        /* Information about this WHERE */
+  WhereClause *pWC;         /* WHERE clause terms */
+  ExprList *pOrderBy;       /* ORDER BY clause */
+  WhereLoop *pNew;          /* Template WhereLoop */
+  WhereOrSet *pOrSet;       /* Record best loops here, if not NULL */
+};
+
+/*
+** The WHERE clause processing routine has two halves.  The
+** first part does the start of the WHERE loop and the second
+** half does the tail of the WHERE loop.  An instance of
+** this structure is returned by the first half and passed
+** into the second half to give some continuity.
+**
+** An instance of this object holds the complete state of the query
+** planner.
 */
-struct WhereCost {
-  WherePlan plan;    /* The lookup strategy */
-  double rCost;      /* Overall cost of pursuing this search strategy */
-  Bitmask used;      /* Bitmask of cursors used by this plan */
+struct WhereInfo {
+  Parse *pParse;            /* Parsing and code generating context */
+  SrcList *pTabList;        /* List of tables in the join */
+  ExprList *pOrderBy;       /* The ORDER BY clause or NULL */
+  ExprList *pResultSet;     /* Result set. DISTINCT operates on these */
+  WhereLoop *pLoops;        /* List of all WhereLoop objects */
+  Bitmask revMask;          /* Mask of ORDER BY terms that need reversing */
+  WhereCost nRowOut;        /* Estimated number of output rows */
+  u16 wctrlFlags;           /* Flags originally passed to sqlite3WhereBegin() */
+  u8 bOBSat;                /* ORDER BY satisfied by indices */
+  u8 okOnePass;             /* Ok to use one-pass algorithm for UPDATE/DELETE */
+  u8 untestedTerms;         /* Not all WHERE terms resolved by outer loop */
+  u8 eDistinct;             /* One of the WHERE_DISTINCT_* values below */
+  u8 nLevel;                /* Number of nested loop */
+  int iTop;                 /* The very beginning of the WHERE loop */
+  int iContinue;            /* Jump here to continue with next record */
+  int iBreak;               /* Jump here to break out of the loop */
+  int savedNQueryLoop;      /* pParse->nQueryLoop outside the WHERE loop */
+  WhereMaskSet sMaskSet;    /* Map cursor numbers to bitmasks */
+  WhereClause sWC;          /* Decomposition of the WHERE clause */
+  WhereLevel a[1];          /* Information about each nest loop in WHERE */
 };
 
 /*
-** Bitmasks for the operators that indices are able to exploit.  An
+** Bitmasks for the operators on WhereTerm objects.  These are all
+** operators that are of interest to the query planner.  An
 ** OR-ed combination of these values can be used when searching for
-** terms in the where clause.
+** particular WhereTerms within a WhereClause.
 */
 #define WO_IN     0x001
 #define WO_EQ     0x002
@@ -233,74 +450,136 @@ struct WhereCost {
 #define WO_SINGLE 0x0ff       /* Mask of all non-compound WO_* values */
 
 /*
-** Value for wsFlags returned by bestIndex() and stored in
-** WhereLevel.wsFlags.  These flags determine which search
-** strategies are appropriate.
-**
-** The least significant 12 bits is reserved as a mask for WO_ values above.
-** The WhereLevel.wsFlags field is usually set to WO_IN|WO_EQ|WO_ISNULL.
-** But if the table is the right table of a left join, WhereLevel.wsFlags
-** is set to WO_IN|WO_EQ.  The WhereLevel.wsFlags field can then be used as
-** the "op" parameter to findTerm when we are resolving equality constraints.
-** ISNULL constraints will then not be used on the right table of a left
-** join.  Tickets #2177 and #2189.
+** These are definitions of bits in the WhereLoop.wsFlags field.
+** The particular combination of bits in each WhereLoop help to
+** determine the algorithm that WhereLoop represents.
+*/
+#define WHERE_COLUMN_EQ    0x00000001  /* x=EXPR */
+#define WHERE_COLUMN_RANGE 0x00000002  /* x<EXPR and/or x>EXPR */
+#define WHERE_COLUMN_IN    0x00000004  /* x IN (...) */
+#define WHERE_COLUMN_NULL  0x00000008  /* x IS NULL */
+#define WHERE_CONSTRAINT   0x0000000f  /* Any of the WHERE_COLUMN_xxx values */
+#define WHERE_TOP_LIMIT    0x00000010  /* x<EXPR or x<=EXPR constraint */
+#define WHERE_BTM_LIMIT    0x00000020  /* x>EXPR or x>=EXPR constraint */
+#define WHERE_BOTH_LIMIT   0x00000030  /* Both x>EXPR and x<EXPR */
+#define WHERE_IDX_ONLY     0x00000040  /* Use index only - omit table */
+#define WHERE_IPK          0x00000100  /* x is the INTEGER PRIMARY KEY */
+#define WHERE_INDEXED      0x00000200  /* WhereLoop.u.btree.pIndex is valid */
+#define WHERE_VIRTUALTABLE 0x00000400  /* WhereLoop.u.vtab is valid */
+#define WHERE_IN_ABLE      0x00000800  /* Able to support an IN operator */
+#define WHERE_ONEROW       0x00001000  /* Selects no more than one row */
+#define WHERE_MULTI_OR     0x00002000  /* OR using multiple indices */
+#define WHERE_AUTO_INDEX   0x00004000  /* Uses an ephemeral index */
+
+
+/* Convert a WhereCost value (10 times log2(X)) into its integer value X.
+** A rough approximation is used.  The value returned is not exact.
 */
-#define WHERE_ROWID_EQ     0x00001000  /* rowid=EXPR or rowid IN (...) */
-#define WHERE_ROWID_RANGE  0x00002000  /* rowid<EXPR and/or rowid>EXPR */
-#define WHERE_COLUMN_EQ    0x00010000  /* x=EXPR or x IN (...) or x IS NULL */
-#define WHERE_COLUMN_RANGE 0x00020000  /* x<EXPR and/or x>EXPR */
-#define WHERE_COLUMN_IN    0x00040000  /* x IN (...) */
-#define WHERE_COLUMN_NULL  0x00080000  /* x IS NULL */
-#define WHERE_INDEXED      0x000f0000  /* Anything that uses an index */
-#define WHERE_NOT_FULLSCAN 0x100f3000  /* Does not do a full table scan */
-#define WHERE_IN_ABLE      0x080f1000  /* Able to support an IN operator */
-#define WHERE_TOP_LIMIT    0x00100000  /* x<EXPR or x<=EXPR constraint */
-#define WHERE_BTM_LIMIT    0x00200000  /* x>EXPR or x>=EXPR constraint */
-#define WHERE_BOTH_LIMIT   0x00300000  /* Both x>EXPR and x<EXPR */
-#define WHERE_IDX_ONLY     0x00400000  /* Use index only - omit table */
-#define WHERE_ORDERED      0x00800000  /* Output will appear in correct order */
-#define WHERE_REVERSE      0x01000000  /* Scan in reverse order */
-#define WHERE_UNIQUE       0x02000000  /* Selects no more than one row */
-#define WHERE_ALL_UNIQUE   0x04000000  /* This and all prior have one row */
-#define WHERE_OB_UNIQUE    0x00004000  /* Values in ORDER BY columns are 
-                                       ** different for every output row */
-#define WHERE_VIRTUALTABLE 0x08000000  /* Use virtual-table processing */
-#define WHERE_MULTI_OR     0x10000000  /* OR using multiple indices */
-#define WHERE_TEMP_INDEX   0x20000000  /* Uses an ephemeral index */
-#define WHERE_DISTINCT     0x40000000  /* Correct order for DISTINCT */
-#define WHERE_COVER_SCAN   0x80000000  /* Full scan of a covering index */
+static u64 whereCostToInt(WhereCost x){
+  u64 n;
+  if( x<10 ) return 1;
+  n = x%10;
+  x /= 10;
+  if( n>=5 ) n -= 2;
+  else if( n>=1 ) n -= 1;
+  if( x>=3 ) return (n+8)<<(x-3);
+  return (n+8)>>(3-x);
+}
 
 /*
-** This module contains many separate subroutines that work together to
-** find the best indices to use for accessing a particular table in a query.
-** An instance of the following structure holds context information about the
-** index search so that it can be more easily passed between the various
-** routines.
+** Return the estimated number of output rows from a WHERE clause
 */
-typedef struct WhereBestIdx WhereBestIdx;
-struct WhereBestIdx {
-  Parse *pParse;                  /* Parser context */
-  WhereClause *pWC;               /* The WHERE clause */
-  struct SrcList_item *pSrc;      /* The FROM clause term to search */
-  Bitmask notReady;               /* Mask of cursors not available */
-  Bitmask notValid;               /* Cursors not available for any purpose */
-  ExprList *pOrderBy;             /* The ORDER BY clause */
-  ExprList *pDistinct;            /* The select-list if query is DISTINCT */
-  sqlite3_index_info **ppIdxInfo; /* Index information passed to xBestIndex */
-  int i, n;                       /* Which loop is being coded; # of loops */
-  WhereLevel *aLevel;             /* Info about outer loops */
-  WhereCost cost;                 /* Lowest cost query plan */
-};
+u64 sqlite3WhereOutputRowCount(WhereInfo *pWInfo){
+  return whereCostToInt(pWInfo->nRowOut);
+}
 
 /*
-** Return TRUE if the probe cost is less than the baseline cost
+** Return one of the WHERE_DISTINCT_xxxxx values to indicate how this
+** WHERE clause returns outputs for DISTINCT processing.
 */
-static int compareCost(const WhereCost *pProbe, const WhereCost *pBaseline){
-  if( pProbe->rCost<pBaseline->rCost ) return 1;
-  if( pProbe->rCost>pBaseline->rCost ) return 0;
-  if( pProbe->plan.nOBSat>pBaseline->plan.nOBSat ) return 1;
-  if( pProbe->plan.nRow<pBaseline->plan.nRow ) return 1;
-  return 0;
+int sqlite3WhereIsDistinct(WhereInfo *pWInfo){
+  return pWInfo->eDistinct;
+}
+
+/*
+** Return TRUE if the WHERE clause returns rows in ORDER BY order.
+** Return FALSE if the output needs to be sorted.
+*/
+int sqlite3WhereIsOrdered(WhereInfo *pWInfo){
+  return pWInfo->bOBSat!=0;
+}
+
+/*
+** Return the VDBE address or label to jump to in order to continue
+** immediately with the next row of a WHERE clause.
+*/
+int sqlite3WhereContinueLabel(WhereInfo *pWInfo){
+  return pWInfo->iContinue;
+}
+
+/*
+** Return the VDBE address or label to jump to in order to break
+** out of a WHERE loop.
+*/
+int sqlite3WhereBreakLabel(WhereInfo *pWInfo){
+  return pWInfo->iBreak;
+}
+
+/*
+** Return TRUE if an UPDATE or DELETE statement can operate directly on
+** the rowids returned by a WHERE clause.  Return FALSE if doing an
+** UPDATE or DELETE might change subsequent WHERE clause results.
+*/
+int sqlite3WhereOkOnePass(WhereInfo *pWInfo){
+  return pWInfo->okOnePass;
+}
+
+/*
+** Move the content of pSrc into pDest
+*/
+static void whereOrMove(WhereOrSet *pDest, WhereOrSet *pSrc){
+  pDest->n = pSrc->n;
+  memcpy(pDest->a, pSrc->a, pDest->n*sizeof(pDest->a[0]));
+}
+
+/*
+** Try to insert a new prerequisite/cost entry into the WhereOrSet pSet.
+**
+** The new entry might overwrite an existing entry, or it might be
+** appended, or it might be discarded.  Do whatever is the right thing
+** so that pSet keeps the N_OR_COST best entries seen so far.
+*/
+static int whereOrInsert(
+  WhereOrSet *pSet,      /* The WhereOrSet to be updated */
+  Bitmask prereq,        /* Prerequisites of the new entry */
+  WhereCost rRun,        /* Run-cost of the new entry */
+  WhereCost nOut         /* Number of outputs for the new entry */
+){
+  u16 i;
+  WhereOrCost *p;
+  for(i=pSet->n, p=pSet->a; i>0; i--, p++){
+    if( rRun<=p->rRun && (prereq & p->prereq)==prereq ){
+      goto whereOrInsert_done;
+    }
+    if( p->rRun<=rRun && (p->prereq & prereq)==p->prereq ){
+      return 0;
+    }
+  }
+  if( pSet->n<N_OR_COST ){
+    p = &pSet->a[pSet->n++];
+    p->nOut = nOut;
+  }else{
+    p = pSet->a;
+    for(i=1; i<pSet->n; i++){
+      if( p->rRun>pSet->a[i].rRun ) p = pSet->a + i;
+    }
+    if( p->rRun<=rRun ) return 0;
+  }
+whereOrInsert_done:
+  p->prereq = prereq;
+  p->rRun = rRun;
+  if( p->nOut>nOut ) p->nOut = nOut;
+  return 1;
 }
 
 /*
@@ -308,17 +587,13 @@ static int compareCost(const WhereCost *pProbe, const WhereCost *pBaseline){
 */
 static void whereClauseInit(
   WhereClause *pWC,        /* The WhereClause to be initialized */
-  Parse *pParse,           /* The parsing context */
-  WhereMaskSet *pMaskSet,  /* Mapping from table cursor numbers to bitmasks */
-  u16 wctrlFlags           /* Might include WHERE_AND_ONLY */
+  WhereInfo *pWInfo        /* The WHERE processing context */
 ){
-  pWC->pParse = pParse;
-  pWC->pMaskSet = pMaskSet;
+  pWC->pWInfo = pWInfo;
   pWC->pOuter = 0;
   pWC->nTerm = 0;
   pWC->nSlot = ArraySize(pWC->aStatic);
   pWC->a = pWC->aStatic;
-  pWC->wctrlFlags = wctrlFlags;
 }
 
 /* Forward reference */
@@ -347,7 +622,7 @@ static void whereAndInfoDelete(sqlite3 *db, WhereAndInfo *p){
 static void whereClauseClear(WhereClause *pWC){
   int i;
   WhereTerm *a;
-  sqlite3 *db = pWC->pParse->db;
+  sqlite3 *db = pWC->pWInfo->pParse->db;
   for(i=pWC->nTerm-1, a=pWC->a; i>=0; i--, a++){
     if( a->wtFlags & TERM_DYNAMIC ){
       sqlite3ExprDelete(db, a->pExpr);
@@ -385,10 +660,10 @@ static void whereClauseClear(WhereClause *pWC){
 static int whereClauseInsert(WhereClause *pWC, Expr *p, u8 wtFlags){
   WhereTerm *pTerm;
   int idx;
-  testcase( wtFlags & TERM_VIRTUAL );  /* EV: R-00211-15100 */
+  testcase( wtFlags & TERM_VIRTUAL );
   if( pWC->nTerm>=pWC->nSlot ){
     WhereTerm *pOld = pWC->a;
-    sqlite3 *db = pWC->pParse->db;
+    sqlite3 *db = pWC->pWInfo->pParse->db;
     pWC->a = sqlite3DbMallocRaw(db, sizeof(pWC->a[0])*pWC->nSlot*2 );
     if( pWC->a==0 ){
       if( wtFlags & TERM_DYNAMIC ){
@@ -428,8 +703,8 @@ static int whereClauseInsert(WhereClause *pWC, Expr *p, u8 wtFlags){
 ** the WhereClause.a[] array.  The slot[] array grows as needed to contain
 ** all terms of the WHERE clause.
 */
-static void whereSplit(WhereClause *pWC, Expr *pExpr, int op){
-  pWC->op = (u8)op;
+static void whereSplit(WhereClause *pWC, Expr *pExpr, u8 op){
+  pWC->op = op;
   if( pExpr==0 ) return;
   if( pExpr->op!=op ){
     whereClauseInsert(pWC, pExpr, 0);
@@ -440,9 +715,9 @@ static void whereSplit(WhereClause *pWC, Expr *pExpr, int op){
 }
 
 /*
-** Initialize an expression mask set (a WhereMaskSet object)
+** Initialize a WhereMaskSet object
 */
-#define initMaskSet(P)  memset(P, 0, sizeof(*P))
+#define initMaskSet(P)  (P)->n=0
 
 /*
 ** Return the bitmask for the given cursor number.  Return 0 if
@@ -453,7 +728,7 @@ static Bitmask getMask(WhereMaskSet *pMaskSet, int iCursor){
   assert( pMaskSet->n<=(int)sizeof(Bitmask)*8 );
   for(i=0; i<pMaskSet->n; i++){
     if( pMaskSet->ix[i]==iCursor ){
-      return ((Bitmask)1)<<i;
+      return MASKBIT(i);
     }
   }
   return 0;
@@ -473,18 +748,9 @@ static void createMask(WhereMaskSet *pMaskSet, int iCursor){
 }
 
 /*
-** This routine walks (recursively) an expression tree and generates
+** These routines walk (recursively) an expression tree and generate
 ** a bitmask indicating which tables are used in that expression
 ** tree.
-**
-** In order for this routine to work, the calling function must have
-** previously invoked sqlite3ResolveExprNames() on the expression.  See
-** the header comment on that routine for additional information.
-** The sqlite3ResolveExprNames() routines looks for column names and
-** sets their opcodes to TK_COLUMN and their Expr.iTable fields to
-** the VDBE cursor number of the table.  This routine just has to
-** translate the cursor numbers into bitmask values and OR all
-** the bitmasks together.
 */
 static Bitmask exprListTableUsage(WhereMaskSet*, ExprList*);
 static Bitmask exprSelectTableUsage(WhereMaskSet*, Select*);
@@ -538,14 +804,7 @@ static Bitmask exprSelectTableUsage(WhereMaskSet *pMaskSet, Select *pS){
 /*
 ** Return TRUE if the given operator is one of the operators that is
 ** allowed for an indexable WHERE clause term.  The allowed operators are
-** "=", "<", ">", "<=", ">=", and "IN".
-**
-** IMPLEMENTATION-OF: R-59926-26393 To be usable by an index a term must be
-** of one of the following forms: column = expression column > expression
-** column >= expression column < expression column <= expression
-** expression = column expression > column expression >= column
-** expression < column expression <= column column IN
-** (expression-list) column IN (subquery) column IS NULL
+** "=", "<", ">", "<=", ">=", "IN", and "IS NULL"
 */
 static int allowedOp(int op){
   assert( TK_GT>TK_EQ && TK_GT<TK_GE );
@@ -565,10 +824,9 @@ static int allowedOp(int op){
 ** are converted into "Y op X".
 **
 ** If left/right precedence rules come into play when determining the
-** collating
-** side of the comparison, it remains associated with the same side after
-** the commutation. So "Y collate NOCASE op X" becomes 
-** "X op Y". This is because any collation sequence on
+** collating sequence, then COLLATE operators are adjusted to ensure
+** that the collating sequence does not change.  For example:
+** "Y collate NOCASE op X" becomes "X op Y" because any collation sequence on
 ** the left hand side of a comparison overrides any collation sequence 
 ** attached to the right. For the same reason the EP_Collate flag
 ** is not commuted.
@@ -626,6 +884,130 @@ static u16 operatorMask(int op){
 }
 
 /*
+** Advance to the next WhereTerm that matches according to the criteria
+** established when the pScan object was initialized by whereScanInit().
+** Return NULL if there are no more matching WhereTerms.
+*/
+static WhereTerm *whereScanNext(WhereScan *pScan){
+  int iCur;            /* The cursor on the LHS of the term */
+  int iColumn;         /* The column on the LHS of the term.  -1 for IPK */
+  Expr *pX;            /* An expression being tested */
+  WhereClause *pWC;    /* Shorthand for pScan->pWC */
+  WhereTerm *pTerm;    /* The term being tested */
+  int k = pScan->k;    /* Where to start scanning */
+
+  while( pScan->iEquiv<=pScan->nEquiv ){
+    iCur = pScan->aEquiv[pScan->iEquiv-2];
+    iColumn = pScan->aEquiv[pScan->iEquiv-1];
+    while( (pWC = pScan->pWC)!=0 ){
+      for(pTerm=pWC->a+k; k<pWC->nTerm; k++, pTerm++){
+        if( pTerm->leftCursor==iCur && pTerm->u.leftColumn==iColumn ){
+          if( (pTerm->eOperator & WO_EQUIV)!=0
+           && pScan->nEquiv<ArraySize(pScan->aEquiv)
+          ){
+            int j;
+            pX = sqlite3ExprSkipCollate(pTerm->pExpr->pRight);
+            assert( pX->op==TK_COLUMN );
+            for(j=0; j<pScan->nEquiv; j+=2){
+              if( pScan->aEquiv[j]==pX->iTable
+               && pScan->aEquiv[j+1]==pX->iColumn ){
+                  break;
+              }
+            }
+            if( j==pScan->nEquiv ){
+              pScan->aEquiv[j] = pX->iTable;
+              pScan->aEquiv[j+1] = pX->iColumn;
+              pScan->nEquiv += 2;
+            }
+          }
+          if( (pTerm->eOperator & pScan->opMask)!=0 ){
+            /* Verify the affinity and collating sequence match */
+            if( pScan->zCollName && (pTerm->eOperator & WO_ISNULL)==0 ){
+              CollSeq *pColl;
+              Parse *pParse = pWC->pWInfo->pParse;
+              pX = pTerm->pExpr;
+              if( !sqlite3IndexAffinityOk(pX, pScan->idxaff) ){
+                continue;
+              }
+              assert(pX->pLeft);
+              pColl = sqlite3BinaryCompareCollSeq(pParse,
+                                                  pX->pLeft, pX->pRight);
+              if( pColl==0 ) pColl = pParse->db->pDfltColl;
+              if( sqlite3StrICmp(pColl->zName, pScan->zCollName) ){
+                continue;
+              }
+            }
+            if( (pTerm->eOperator & WO_EQ)!=0
+             && (pX = pTerm->pExpr->pRight)->op==TK_COLUMN
+             && pX->iTable==pScan->aEquiv[0]
+             && pX->iColumn==pScan->aEquiv[1]
+            ){
+              continue;
+            }
+            pScan->k = k+1;
+            return pTerm;
+          }
+        }
+      }
+      pScan->pWC = pScan->pWC->pOuter;
+      k = 0;
+    }
+    pScan->pWC = pScan->pOrigWC;
+    k = 0;
+    pScan->iEquiv += 2;
+  }
+  return 0;
+}
+
+/*
+** Initialize a WHERE clause scanner object.  Return a pointer to the
+** first match.  Return NULL if there are no matches.
+**
+** The scanner will be searching the WHERE clause pWC.  It will look
+** for terms of the form "X <op> <expr>" where X is column iColumn of table
+** iCur.  The <op> must be one of the operators described by opMask.
+**
+** If the search is for X and the WHERE clause contains terms of the
+** form X=Y then this routine might also return terms of the form
+** "Y <op> <expr>".  The number of levels of transitivity is limited,
+** but is enough to handle most commonly occurring SQL statements.
+**
+** If X is not the INTEGER PRIMARY KEY then X must be compatible with
+** index pIdx.
+*/
+static WhereTerm *whereScanInit(
+  WhereScan *pScan,       /* The WhereScan object being initialized */
+  WhereClause *pWC,       /* The WHERE clause to be scanned */
+  int iCur,               /* Cursor to scan for */
+  int iColumn,            /* Column to scan for */
+  u32 opMask,             /* Operator(s) to scan for */
+  Index *pIdx             /* Must be compatible with this index */
+){
+  int j;
+
+  /* memset(pScan, 0, sizeof(*pScan)); */
+  pScan->pOrigWC = pWC;
+  pScan->pWC = pWC;
+  if( pIdx && iColumn>=0 ){
+    pScan->idxaff = pIdx->pTable->aCol[iColumn].affinity;
+    for(j=0; pIdx->aiColumn[j]!=iColumn; j++){
+      if( NEVER(j>=pIdx->nColumn) ) return 0;
+    }
+    pScan->zCollName = pIdx->azColl[j];
+  }else{
+    pScan->idxaff = 0;
+    pScan->zCollName = 0;
+  }
+  pScan->opMask = opMask;
+  pScan->k = 0;
+  pScan->aEquiv[0] = iCur;
+  pScan->aEquiv[1] = iColumn;
+  pScan->nEquiv = 2;
+  pScan->iEquiv = 2;
+  return whereScanNext(pScan);
+}
+
+/*
 ** Search for a term in the WHERE clause that is of the form "X <op> <expr>"
 ** where X is a reference to the iColumn of table iCur and <op> is one of
 ** the WO_xx operator codes specified by the op parameter.
@@ -656,84 +1038,20 @@ static WhereTerm *findTerm(
   u32 op,               /* Mask of WO_xx values describing operator */
   Index *pIdx           /* Must be compatible with this index, if not NULL */
 ){
-  WhereTerm *pTerm;            /* Term being examined as possible result */
-  WhereTerm *pResult = 0;      /* The answer to return */
-  WhereClause *pWCOrig = pWC;  /* Original pWC value */
-  int j, k;                    /* Loop counters */
-  Expr *pX;                /* Pointer to an expression */
-  Parse *pParse;           /* Parsing context */
-  int iOrigCol = iColumn;  /* Original value of iColumn */
-  int nEquiv = 2;          /* Number of entires in aEquiv[] */
-  int iEquiv = 2;          /* Number of entries of aEquiv[] processed so far */
-  int aEquiv[22];          /* iCur,iColumn and up to 10 other equivalents */
-
-  assert( iCur>=0 );
-  aEquiv[0] = iCur;
-  aEquiv[1] = iColumn;
-  for(;;){
-    for(pWC=pWCOrig; pWC; pWC=pWC->pOuter){
-      for(pTerm=pWC->a, k=pWC->nTerm; k; k--, pTerm++){
-        if( pTerm->leftCursor==iCur
-          && pTerm->u.leftColumn==iColumn
-        ){
-          if( (pTerm->prereqRight & notReady)==0
-           && (pTerm->eOperator & op & WO_ALL)!=0
-          ){
-            if( iOrigCol>=0 && pIdx && (pTerm->eOperator & WO_ISNULL)==0 ){
-              CollSeq *pColl;
-              char idxaff;
-      
-              pX = pTerm->pExpr;
-              pParse = pWC->pParse;
-              idxaff = pIdx->pTable->aCol[iOrigCol].affinity;
-              if( !sqlite3IndexAffinityOk(pX, idxaff) ){
-                continue;
-              }
-      
-              /* Figure out the collation sequence required from an index for
-              ** it to be useful for optimising expression pX. Store this
-              ** value in variable pColl.
-              */
-              assert(pX->pLeft);
-              pColl = sqlite3BinaryCompareCollSeq(pParse,pX->pLeft,pX->pRight);
-              if( pColl==0 ) pColl = pParse->db->pDfltColl;
-      
-              for(j=0; pIdx->aiColumn[j]!=iOrigCol; j++){
-                if( NEVER(j>=pIdx->nColumn) ) return 0;
-              }
-              if( sqlite3StrICmp(pColl->zName, pIdx->azColl[j]) ){
-                continue;
-              }
-            }
-            if( pTerm->prereqRight==0 && (pTerm->eOperator&WO_EQ)!=0 ){
-              pResult = pTerm;
-              goto findTerm_success;
-            }else if( pResult==0 ){
-              pResult = pTerm;
-            }
-          }
-          if( (pTerm->eOperator & WO_EQUIV)!=0
-           && nEquiv<ArraySize(aEquiv)
-          ){
-            pX = sqlite3ExprSkipCollate(pTerm->pExpr->pRight);
-            assert( pX->op==TK_COLUMN );
-            for(j=0; j<nEquiv; j+=2){
-              if( aEquiv[j]==pX->iTable && aEquiv[j+1]==pX->iColumn ) break;
-            }
-            if( j==nEquiv ){
-              aEquiv[j] = pX->iTable;
-              aEquiv[j+1] = pX->iColumn;
-              nEquiv += 2;
-            }
-          }
-        }
+  WhereTerm *pResult = 0;
+  WhereTerm *p;
+  WhereScan scan;
+
+  p = whereScanInit(&scan, pWC, iCur, iColumn, op, pIdx);
+  while( p ){
+    if( (p->prereqRight & notReady)==0 ){
+      if( p->prereqRight==0 && (p->eOperator&WO_EQ)!=0 ){
+        return p;
       }
+      if( pResult==0 ) pResult = p;
     }
-    if( iEquiv>=nEquiv ) break;
-    iCur = aEquiv[iEquiv++];
-    iColumn = aEquiv[iEquiv++];
+    p = whereScanNext(&scan);
   }
-findTerm_success:
   return pResult;
 }
 
@@ -742,8 +1060,6 @@ static void exprAnalyze(SrcList*, WhereClause*, int);
 
 /*
 ** Call exprAnalyze on all terms in a WHERE clause.  
-**
-**
 */
 static void exprAnalyzeAll(
   SrcList *pTabList,       /* the FROM clause */
@@ -807,7 +1123,7 @@ static int isLikeOrGlob(
   if( op==TK_VARIABLE ){
     Vdbe *pReprepare = pParse->pReprepare;
     int iCol = pRight->iColumn;
-    pVal = sqlite3VdbeGetValue(pReprepare, iCol, SQLITE_AFF_NONE);
+    pVal = sqlite3VdbeGetBoundValue(pReprepare, iCol, SQLITE_AFF_NONE);
     if( pVal && sqlite3_value_type(pVal)==SQLITE_TEXT ){
       z = (char *)sqlite3_value_text(pVal);
     }
@@ -889,8 +1205,10 @@ static int isMatchOfColumn(
 ** a join, then transfer the appropriate markings over to derived.
 */
 static void transferJoinMarkings(Expr *pDerived, Expr *pBase){
-  pDerived->flags |= pBase->flags & EP_FromJoin;
-  pDerived->iRightJoinTable = pBase->iRightJoinTable;
+  if( pDerived ){
+    pDerived->flags |= pBase->flags & EP_FromJoin;
+    pDerived->iRightJoinTable = pBase->iRightJoinTable;
+  }
 }
 
 #if !defined(SQLITE_OMIT_OR_OPTIMIZATION) && !defined(SQLITE_OMIT_SUBQUERY)
@@ -949,10 +1267,10 @@ static void transferJoinMarkings(Expr *pDerived, Expr *pBase){
 ** From another point of view, "indexable" means that the subterm could
 ** potentially be used with an index if an appropriate index exists.
 ** This analysis does not consider whether or not the index exists; that
-** is something the bestIndex() routine will determine.  This analysis
-** only looks at whether subterms appropriate for indexing exist.
+** is decided elsewhere.  This analysis only looks at whether subterms
+** appropriate for indexing exist.
 **
-** All examples A through E above all satisfy case 2.  But if a term
+** All examples A through E above satisfy case 2.  But if a term
 ** also statisfies case 1 (such as B) we know that the optimizer will
 ** always prefer case 1, so in that case we pretend that case 2 is not
 ** satisfied.
@@ -975,11 +1293,11 @@ static void exprAnalyzeOrTerm(
   WhereClause *pWC,         /* the complete WHERE clause */
   int idxTerm               /* Index of the OR-term to be analyzed */
 ){
-  Parse *pParse = pWC->pParse;            /* Parser context */
+  WhereInfo *pWInfo = pWC->pWInfo;        /* WHERE clause processing context */
+  Parse *pParse = pWInfo->pParse;         /* Parser context */
   sqlite3 *db = pParse->db;               /* Database connection */
   WhereTerm *pTerm = &pWC->a[idxTerm];    /* The term to be analyzed */
   Expr *pExpr = pTerm->pExpr;             /* The expression of the term */
-  WhereMaskSet *pMaskSet = pWC->pMaskSet; /* Table use masks */
   int i;                                  /* Loop counters */
   WhereClause *pOrWc;       /* Breakup of pTerm into subterms */
   WhereTerm *pOrTerm;       /* A Sub-term within the pOrWc */
@@ -998,7 +1316,7 @@ static void exprAnalyzeOrTerm(
   if( pOrInfo==0 ) return;
   pTerm->wtFlags |= TERM_ORINFO;
   pOrWc = &pOrInfo->wc;
-  whereClauseInit(pOrWc, pWC->pParse, pMaskSet, pWC->wctrlFlags);
+  whereClauseInit(pOrWc, pWInfo);
   whereSplit(pOrWc, pExpr, TK_OR);
   exprAnalyzeAll(pSrc, pOrWc);
   if( db->mallocFailed ) return;
@@ -1024,7 +1342,7 @@ static void exprAnalyzeOrTerm(
         pOrTerm->wtFlags |= TERM_ANDINFO;
         pOrTerm->eOperator = WO_AND;
         pAndWC = &pAndInfo->wc;
-        whereClauseInit(pAndWC, pWC->pParse, pMaskSet, pWC->wctrlFlags);
+        whereClauseInit(pAndWC, pWC->pWInfo);
         whereSplit(pAndWC, pOrTerm->pExpr, TK_AND);
         exprAnalyzeAll(pSrc, pAndWC);
         pAndWC->pOuter = pWC;
@@ -1033,7 +1351,7 @@ static void exprAnalyzeOrTerm(
           for(j=0, pAndTerm=pAndWC->a; j<pAndWC->nTerm; j++, pAndTerm++){
             assert( pAndTerm->pExpr );
             if( allowedOp(pAndTerm->pExpr->op) ){
-              b |= getMask(pMaskSet, pAndTerm->leftCursor);
+              b |= getMask(&pWInfo->sMaskSet, pAndTerm->leftCursor);
             }
           }
         }
@@ -1044,10 +1362,10 @@ static void exprAnalyzeOrTerm(
       ** corresponding TERM_VIRTUAL term */
     }else{
       Bitmask b;
-      b = getMask(pMaskSet, pOrTerm->leftCursor);
+      b = getMask(&pWInfo->sMaskSet, pOrTerm->leftCursor);
       if( pOrTerm->wtFlags & TERM_VIRTUAL ){
         WhereTerm *pOther = &pOrWc->a[pOrTerm->iParent];
-        b |= getMask(pMaskSet, pOther->leftCursor);
+        b |= getMask(&pWInfo->sMaskSet, pOther->leftCursor);
       }
       indexable &= b;
       if( (pOrTerm->eOperator & WO_EQ)==0 ){
@@ -1109,7 +1427,7 @@ static void exprAnalyzeOrTerm(
           assert( j==1 );
           continue;
         }
-        if( (chngToIN & getMask(pMaskSet, pOrTerm->leftCursor))==0 ){
+        if( (chngToIN & getMask(&pWInfo->sMaskSet, pOrTerm->leftCursor))==0 ){
           /* This term must be of the form t1.a==t2.b where t2 is in the
           ** chngToIN set but t1 is not.  This term will be either preceeded
           ** or follwed by an inverted copy (t2.b==t1.a).  Skip this term 
@@ -1128,7 +1446,7 @@ static void exprAnalyzeOrTerm(
         ** on the second iteration */
         assert( j==1 );
         assert( IsPowerOfTwo(chngToIN) );
-        assert( chngToIN==getMask(pMaskSet, iCursor) );
+        assert( chngToIN==getMask(&pWInfo->sMaskSet, iCursor) );
         break;
       }
       testcase( j==1 );
@@ -1162,8 +1480,6 @@ static void exprAnalyzeOrTerm(
     /* At this point, okToChngToIN is true if original pTerm satisfies
     ** case 1.  In that case, construct a new virtual term that is 
     ** pTerm converted into an IN operator.
-    **
-    ** EV: R-00211-15100
     */
     if( okToChngToIN ){
       Expr *pDup;            /* A transient duplicate expression */
@@ -1177,7 +1493,7 @@ static void exprAnalyzeOrTerm(
         assert( pOrTerm->leftCursor==iCursor );
         assert( pOrTerm->u.leftColumn==iColumn );
         pDup = sqlite3ExprDup(db, pOrTerm->pExpr->pRight, 0);
-        pList = sqlite3ExprListAppend(pWC->pParse, pList, pDup);
+        pList = sqlite3ExprListAppend(pWInfo->pParse, pList, pDup);
         pLeft = pOrTerm->pExpr->pLeft;
       }
       assert( pLeft!=0 );
@@ -1226,6 +1542,7 @@ static void exprAnalyze(
   WhereClause *pWC,         /* the WHERE clause */
   int idxTerm               /* Index of the term to be analyzed */
 ){
+  WhereInfo *pWInfo = pWC->pWInfo; /* WHERE clause processing context */
   WhereTerm *pTerm;                /* The term to be analyzed */
   WhereMaskSet *pMaskSet;          /* Set of table index masks */
   Expr *pExpr;                     /* The expression to be analyzed */
@@ -1236,14 +1553,14 @@ static void exprAnalyze(
   int isComplete = 0;              /* RHS of LIKE/GLOB ends with wildcard */
   int noCase = 0;                  /* LIKE/GLOB distinguishes case */
   int op;                          /* Top-level operator.  pExpr->op */
-  Parse *pParse = pWC->pParse;     /* Parsing context */
+  Parse *pParse = pWInfo->pParse;  /* Parsing context */
   sqlite3 *db = pParse->db;        /* Database connection */
 
   if( db->mallocFailed ){
     return;
   }
   pTerm = &pWC->a[idxTerm];
-  pMaskSet = pWC->pMaskSet;
+  pMaskSet = &pWInfo->sMaskSet;
   pExpr = pTerm->pExpr;
   assert( pExpr->op!=TK_AS && pExpr->op!=TK_COLLATE );
   prereqLeft = exprTableUsage(pMaskSet, pExpr->pLeft);
@@ -1348,6 +1665,7 @@ static void exprAnalyze(
       pNewExpr = sqlite3PExpr(pParse, ops[i], 
                              sqlite3ExprDup(db, pExpr->pLeft, 0),
                              sqlite3ExprDup(db, pList->a[i].pExpr, 0), 0);
+      transferJoinMarkings(pNewExpr, pExpr);
       idxNew = whereClauseInsert(pWC, pNewExpr, TERM_VIRTUAL|TERM_DYNAMIC);
       testcase( idxNew==0 );
       exprAnalyze(pSrc, pWC, idxNew);
@@ -1404,9 +1722,7 @@ static void exprAnalyze(
         ** inequality.  To avoid this, make sure to also run the full
         ** LIKE on all candidate expressions by clearing the isComplete flag
         */
-        if( c=='A'-1 ) isComplete = 0;   /* EV: R-64339-08207 */
-
-
+        if( c=='A'-1 ) isComplete = 0;
         c = sqlite3UpperToLower[c];
       }
       *pC = c + 1;
@@ -1417,6 +1733,7 @@ static void exprAnalyze(
     pNewExpr1 = sqlite3PExpr(pParse, TK_GE, 
            sqlite3ExprAddCollateToken(pParse,pNewExpr1,&sCollSeqName),
            pStr1, 0);
+    transferJoinMarkings(pNewExpr1, pExpr);
     idxNew1 = whereClauseInsert(pWC, pNewExpr1, TERM_VIRTUAL|TERM_DYNAMIC);
     testcase( idxNew1==0 );
     exprAnalyze(pSrc, pWC, idxNew1);
@@ -1424,6 +1741,7 @@ static void exprAnalyze(
     pNewExpr2 = sqlite3PExpr(pParse, TK_LT,
            sqlite3ExprAddCollateToken(pParse,pNewExpr2,&sCollSeqName),
            pStr2, 0);
+    transferJoinMarkings(pNewExpr2, pExpr);
     idxNew2 = whereClauseInsert(pWC, pNewExpr2, TERM_VIRTUAL|TERM_DYNAMIC);
     testcase( idxNew2==0 );
     exprAnalyze(pSrc, pWC, idxNew2);
@@ -1487,6 +1805,7 @@ static void exprAnalyze(
   if( pExpr->op==TK_NOTNULL
    && pExpr->pLeft->op==TK_COLUMN
    && pExpr->pLeft->iColumn>=0
+   && OptimizationEnabled(db, SQLITE_Stat3)
   ){
     Expr *pNewExpr;
     Expr *pLeft = pExpr->pLeft;
@@ -1521,11 +1840,8 @@ static void exprAnalyze(
 }
 
 /*
-** This function searches the expression list passed as the second argument
-** for an expression of type TK_COLUMN that refers to the same column and
-** uses the same collation sequence as the iCol'th column of index pIdx.
-** Argument iBase is the cursor number used for the table that pIdx refers
-** to.
+** This function searches pList for a entry that matches the iCol-th column
+** of index pIdx.
 **
 ** If such an expression is found, its index in pList->a[] is returned. If
 ** no expression is found, -1 is returned.
@@ -1557,76 +1873,17 @@ static int findIndexCol(
 }
 
 /*
-** This routine determines if pIdx can be used to assist in processing a
-** DISTINCT qualifier. In other words, it tests whether or not using this
-** index for the outer loop guarantees that rows with equal values for
-** all expressions in the pDistinct list are delivered grouped together.
-**
-** For example, the query 
-**
-**   SELECT DISTINCT a, b, c FROM tbl WHERE a = ?
-**
-** can benefit from any index on columns "b" and "c".
-*/
-static int isDistinctIndex(
-  Parse *pParse,                  /* Parsing context */
-  WhereClause *pWC,               /* The WHERE clause */
-  Index *pIdx,                    /* The index being considered */
-  int base,                       /* Cursor number for the table pIdx is on */
-  ExprList *pDistinct,            /* The DISTINCT expressions */
-  int nEqCol                      /* Number of index columns with == */
-){
-  Bitmask mask = 0;               /* Mask of unaccounted for pDistinct exprs */
-  int i;                          /* Iterator variable */
-
-  assert( pDistinct!=0 );
-  if( pIdx->zName==0 || pDistinct->nExpr>=BMS ) return 0;
-  testcase( pDistinct->nExpr==BMS-1 );
-
-  /* Loop through all the expressions in the distinct list. If any of them
-  ** are not simple column references, return early. Otherwise, test if the
-  ** WHERE clause contains a "col=X" clause. If it does, the expression
-  ** can be ignored. If it does not, and the column does not belong to the
-  ** same table as index pIdx, return early. Finally, if there is no
-  ** matching "col=X" expression and the column is on the same table as pIdx,
-  ** set the corresponding bit in variable mask.
-  */
-  for(i=0; i<pDistinct->nExpr; i++){
-    WhereTerm *pTerm;
-    Expr *p = sqlite3ExprSkipCollate(pDistinct->a[i].pExpr);
-    if( p->op!=TK_COLUMN ) return 0;
-    pTerm = findTerm(pWC, p->iTable, p->iColumn, ~(Bitmask)0, WO_EQ, 0);
-    if( pTerm ){
-      Expr *pX = pTerm->pExpr;
-      CollSeq *p1 = sqlite3BinaryCompareCollSeq(pParse, pX->pLeft, pX->pRight);
-      CollSeq *p2 = sqlite3ExprCollSeq(pParse, p);
-      if( p1==p2 ) continue;
-    }
-    if( p->iTable!=base ) return 0;
-    mask |= (((Bitmask)1) << i);
-  }
-
-  for(i=nEqCol; mask && i<pIdx->nColumn; i++){
-    int iExpr = findIndexCol(pParse, pDistinct, base, pIdx, i);
-    if( iExpr<0 ) break;
-    mask &= ~(((Bitmask)1) << iExpr);
-  }
-
-  return (mask==0);
-}
-
-
-/*
 ** Return true if the DISTINCT expression-list passed as the third argument
-** is redundant. A DISTINCT list is redundant if the database contains a
-** UNIQUE index that guarantees that the result of the query will be distinct
-** anyway.
+** is redundant.
+**
+** A DISTINCT list is redundant if the database contains some subset of
+** columns that are unique and non-null.
 */
 static int isDistinctRedundant(
-  Parse *pParse,
-  SrcList *pTabList,
-  WhereClause *pWC,
-  ExprList *pDistinct
+  Parse *pParse,            /* Parsing context */
+  SrcList *pTabList,        /* The FROM clause */
+  WhereClause *pWC,         /* The WHERE clause */
+  ExprList *pDistinct       /* The result set that needs to be DISTINCT */
 ){
   Table *pTab;
   Index *pIdx;
@@ -1682,21 +1939,76 @@ static int isDistinctRedundant(
   return 0;
 }
 
+/* 
+** Find (an approximate) sum of two WhereCosts.  This computation is
+** not a simple "+" operator because WhereCost is stored as a logarithmic
+** value.
+** 
+*/
+static WhereCost whereCostAdd(WhereCost a, WhereCost b){
+  static const unsigned char x[] = {
+     10, 10,                         /* 0,1 */
+      9, 9,                          /* 2,3 */
+      8, 8,                          /* 4,5 */
+      7, 7, 7,                       /* 6,7,8 */
+      6, 6, 6,                       /* 9,10,11 */
+      5, 5, 5,                       /* 12-14 */
+      4, 4, 4, 4,                    /* 15-18 */
+      3, 3, 3, 3, 3, 3,              /* 19-24 */
+      2, 2, 2, 2, 2, 2, 2,           /* 25-31 */
+  };
+  if( a>=b ){
+    if( a>b+49 ) return a;
+    if( a>b+31 ) return a+1;
+    return a+x[a-b];
+  }else{
+    if( b>a+49 ) return b;
+    if( b>a+31 ) return b+1;
+    return b+x[b-a];
+  }
+}
+
 /*
-** Prepare a crude estimate of the logarithm of the input value.
-** The results need not be exact.  This is only used for estimating
-** the total cost of performing operations with O(logN) or O(NlogN)
-** complexity.  Because N is just a guess, it is no great tragedy if
-** logN is a little off.
+** Convert an integer into a WhereCost.  In other words, compute a
+** good approximatation for 10*log2(x).
 */
-static double estLog(double N){
-  double logN = 1;
-  double x = 10;
-  while( N>x ){
-    logN += 1;
-    x *= 10;
-  }
-  return logN;
+static WhereCost whereCost(tRowcnt x){
+  static WhereCost a[] = { 0, 2, 3, 5, 6, 7, 8, 9 };
+  WhereCost y = 40;
+  if( x<8 ){
+    if( x<2 ) return 0;
+    while( x<8 ){  y -= 10; x <<= 1; }
+  }else{
+    while( x>255 ){ y += 40; x >>= 4; }
+    while( x>15 ){  y += 10; x >>= 1; }
+  }
+  return a[x&7] + y - 10;
+}
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/*
+** Convert a double (as received from xBestIndex of a virtual table)
+** into a WhereCost.  In other words, compute an approximation for
+** 10*log2(x).
+*/
+static WhereCost whereCostFromDouble(double x){
+  u64 a;
+  WhereCost e;
+  assert( sizeof(x)==8 && sizeof(a)==8 );
+  if( x<=1 ) return 0;
+  if( x<=2000000000 ) return whereCost((tRowcnt)x);
+  memcpy(&a, &x, 8);
+  e = (a>>52) - 1022;
+  return e*10;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+/*
+** Estimate the logarithm of the input value to base 2.
+*/
+static WhereCost estLog(WhereCost N){
+  WhereCost x = whereCost(N);
+  return x>33 ? x - 33 : 0;
 }
 
 /*
@@ -1705,7 +2017,7 @@ static double estLog(double N){
 ** SQLITE_TEST or SQLITE_DEBUG are defined, then these routines
 ** are no-ops.
 */
-#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(SQLITE_DEBUG)
+#if !defined(SQLITE_OMIT_VIRTUALTABLE) && defined(WHERETRACE_ENABLED)
 static void TRACE_IDX_INPUTS(sqlite3_index_info *p){
   int i;
   if( !sqlite3WhereTrace ) return;
@@ -1743,107 +2055,6 @@ static void TRACE_IDX_OUTPUTS(sqlite3_index_info *p){
 #define TRACE_IDX_OUTPUTS(A)
 #endif
 
-/* 
-** Required because bestIndex() is called by bestOrClauseIndex() 
-*/
-static void bestIndex(WhereBestIdx*);
-
-/*
-** This routine attempts to find an scanning strategy that can be used 
-** to optimize an 'OR' expression that is part of a WHERE clause. 
-**
-** The table associated with FROM clause term pSrc may be either a
-** regular B-Tree table or a virtual table.
-*/
-static void bestOrClauseIndex(WhereBestIdx *p){
-#ifndef SQLITE_OMIT_OR_OPTIMIZATION
-  WhereClause *pWC = p->pWC;           /* The WHERE clause */
-  struct SrcList_item *pSrc = p->pSrc; /* The FROM clause term to search */
-  const int iCur = pSrc->iCursor;      /* The cursor of the table  */
-  const Bitmask maskSrc = getMask(pWC->pMaskSet, iCur);  /* Bitmask for pSrc */
-  WhereTerm * const pWCEnd = &pWC->a[pWC->nTerm];        /* End of pWC->a[] */
-  WhereTerm *pTerm;                    /* A single term of the WHERE clause */
-
-  /* The OR-clause optimization is disallowed if the INDEXED BY or
-  ** NOT INDEXED clauses are used or if the WHERE_AND_ONLY bit is set. */
-  if( pSrc->notIndexed || pSrc->pIndex!=0 ){
-    return;
-  }
-  if( pWC->wctrlFlags & WHERE_AND_ONLY ){
-    return;
-  }
-
-  /* Search the WHERE clause terms for a usable WO_OR term. */
-  for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){
-    if( (pTerm->eOperator & WO_OR)!=0
-     && ((pTerm->prereqAll & ~maskSrc) & p->notReady)==0
-     && (pTerm->u.pOrInfo->indexable & maskSrc)!=0 
-    ){
-      WhereClause * const pOrWC = &pTerm->u.pOrInfo->wc;
-      WhereTerm * const pOrWCEnd = &pOrWC->a[pOrWC->nTerm];
-      WhereTerm *pOrTerm;
-      int flags = WHERE_MULTI_OR;
-      double rTotal = 0;
-      double nRow = 0;
-      Bitmask used = 0;
-      WhereBestIdx sBOI;
-
-      sBOI = *p;
-      sBOI.pOrderBy = 0;
-      sBOI.pDistinct = 0;
-      sBOI.ppIdxInfo = 0;
-      for(pOrTerm=pOrWC->a; pOrTerm<pOrWCEnd; pOrTerm++){
-        WHERETRACE(("... Multi-index OR testing for term %d of %d....\n", 
-          (pOrTerm - pOrWC->a), (pTerm - pWC->a)
-        ));
-        if( (pOrTerm->eOperator& WO_AND)!=0 ){
-          sBOI.pWC = &pOrTerm->u.pAndInfo->wc;
-          bestIndex(&sBOI);
-        }else if( pOrTerm->leftCursor==iCur ){
-          WhereClause tempWC;
-          tempWC.pParse = pWC->pParse;
-          tempWC.pMaskSet = pWC->pMaskSet;
-          tempWC.pOuter = pWC;
-          tempWC.op = TK_AND;
-          tempWC.a = pOrTerm;
-          tempWC.wctrlFlags = 0;
-          tempWC.nTerm = 1;
-          sBOI.pWC = &tempWC;
-          bestIndex(&sBOI);
-        }else{
-          continue;
-        }
-        rTotal += sBOI.cost.rCost;
-        nRow += sBOI.cost.plan.nRow;
-        used |= sBOI.cost.used;
-        if( rTotal>=p->cost.rCost ) break;
-      }
-
-      /* If there is an ORDER BY clause, increase the scan cost to account 
-      ** for the cost of the sort. */
-      if( p->pOrderBy!=0 ){
-        WHERETRACE(("... sorting increases OR cost %.9g to %.9g\n",
-                    rTotal, rTotal+nRow*estLog(nRow)));
-        rTotal += nRow*estLog(nRow);
-      }
-
-      /* If the cost of scanning using this OR term for optimization is
-      ** less than the current cost stored in pCost, replace the contents
-      ** of pCost. */
-      WHERETRACE(("... multi-index OR cost=%.9g nrow=%.9g\n", rTotal, nRow));
-      if( rTotal<p->cost.rCost ){
-        p->cost.rCost = rTotal;
-        p->cost.used = used;
-        p->cost.plan.nRow = nRow;
-        p->cost.plan.nOBSat = p->i ? p->aLevel[p->i-1].plan.nOBSat : 0;
-        p->cost.plan.wsFlags = flags;
-        p->cost.plan.u.pTerm = pTerm;
-      }
-    }
-  }
-#endif /* SQLITE_OMIT_OR_OPTIMIZATION */
-}
-
 #ifndef SQLITE_OMIT_AUTOMATIC_INDEX
 /*
 ** Return TRUE if the WHERE clause term pTerm is of a form where it
@@ -1859,88 +2070,13 @@ static int termCanDriveIndex(
   if( pTerm->leftCursor!=pSrc->iCursor ) return 0;
   if( (pTerm->eOperator & WO_EQ)==0 ) return 0;
   if( (pTerm->prereqRight & notReady)!=0 ) return 0;
+  if( pTerm->u.leftColumn<0 ) return 0;
   aff = pSrc->pTab->aCol[pTerm->u.leftColumn].affinity;
   if( !sqlite3IndexAffinityOk(pTerm->pExpr, aff) ) return 0;
   return 1;
 }
 #endif
 
-#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
-/*
-** If the query plan for pSrc specified in pCost is a full table scan
-** and indexing is allows (if there is no NOT INDEXED clause) and it
-** possible to construct a transient index that would perform better
-** than a full table scan even when the cost of constructing the index
-** is taken into account, then alter the query plan to use the
-** transient index.
-*/
-static void bestAutomaticIndex(WhereBestIdx *p){
-  Parse *pParse = p->pParse;            /* The parsing context */
-  WhereClause *pWC = p->pWC;            /* The WHERE clause */
-  struct SrcList_item *pSrc = p->pSrc;  /* The FROM clause term to search */
-  double nTableRow;                     /* Rows in the input table */
-  double logN;                          /* log(nTableRow) */
-  double costTempIdx;         /* per-query cost of the transient index */
-  WhereTerm *pTerm;           /* A single term of the WHERE clause */
-  WhereTerm *pWCEnd;          /* End of pWC->a[] */
-  Table *pTable;              /* Table tht might be indexed */
-
-  if( pParse->nQueryLoop<=(double)1 ){
-    /* There is no point in building an automatic index for a single scan */
-    return;
-  }
-  if( (pParse->db->flags & SQLITE_AutoIndex)==0 ){
-    /* Automatic indices are disabled at run-time */
-    return;
-  }
-  if( (p->cost.plan.wsFlags & WHERE_NOT_FULLSCAN)!=0
-   && (p->cost.plan.wsFlags & WHERE_COVER_SCAN)==0
-  ){
-    /* We already have some kind of index in use for this query. */
-    return;
-  }
-  if( pSrc->viaCoroutine ){
-    /* Cannot index a co-routine */
-    return;
-  }
-  if( pSrc->notIndexed ){
-    /* The NOT INDEXED clause appears in the SQL. */
-    return;
-  }
-  if( pSrc->isCorrelated ){
-    /* The source is a correlated sub-query. No point in indexing it. */
-    return;
-  }
-
-  assert( pParse->nQueryLoop >= (double)1 );
-  pTable = pSrc->pTab;
-  nTableRow = pTable->nRowEst;
-  logN = estLog(nTableRow);
-  costTempIdx = 2*logN*(nTableRow/pParse->nQueryLoop + 1);
-  if( costTempIdx>=p->cost.rCost ){
-    /* The cost of creating the transient table would be greater than
-    ** doing the full table scan */
-    return;
-  }
-
-  /* Search for any equality comparison term */
-  pWCEnd = &pWC->a[pWC->nTerm];
-  for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){
-    if( termCanDriveIndex(pTerm, pSrc, p->notReady) ){
-      WHERETRACE(("auto-index reduces cost from %.1f to %.1f\n",
-                    p->cost.rCost, costTempIdx));
-      p->cost.rCost = costTempIdx;
-      p->cost.plan.nRow = logN + 1;
-      p->cost.plan.wsFlags = WHERE_TEMP_INDEX;
-      p->cost.used = pTerm->prereqRight;
-      break;
-    }
-  }
-}
-#else
-# define bestAutomaticIndex(A)  /* no-op */
-#endif /* SQLITE_OMIT_AUTOMATIC_INDEX */
-
 
 #ifndef SQLITE_OMIT_AUTOMATIC_INDEX
 /*
@@ -1970,8 +2106,10 @@ static void constructAutomaticIndex(
   int i;                      /* Loop counter */
   int mxBitCol;               /* Maximum column in pSrc->colUsed */
   CollSeq *pColl;             /* Collating sequence to on a column */
+  WhereLoop *pLoop;           /* The Loop object */
   Bitmask idxCols;            /* Bitmap of columns used for indexing */
   Bitmask extraCols;          /* Bitmap of additional columns */
+  u8 sentWarning = 0;         /* True if a warnning has been issued */
 
   /* Generate code to skip over the creation and initialization of the
   ** transient index on 2nd and subsequent iterations of the loop. */
@@ -1984,21 +2122,31 @@ static void constructAutomaticIndex(
   nColumn = 0;
   pTable = pSrc->pTab;
   pWCEnd = &pWC->a[pWC->nTerm];
+  pLoop = pLevel->pWLoop;
   idxCols = 0;
   for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){
     if( termCanDriveIndex(pTerm, pSrc, notReady) ){
       int iCol = pTerm->u.leftColumn;
-      Bitmask cMask = iCol>=BMS ? ((Bitmask)1)<<(BMS-1) : ((Bitmask)1)<<iCol;
+      Bitmask cMask = iCol>=BMS ? MASKBIT(BMS-1) : MASKBIT(iCol);
       testcase( iCol==BMS );
       testcase( iCol==BMS-1 );
+      if( !sentWarning ){
+        sqlite3_log(SQLITE_WARNING_AUTOINDEX,
+            "automatic index on %s(%s)", pTable->zName,
+            pTable->aCol[iCol].zName);
+        sentWarning = 1;
+      }
       if( (idxCols & cMask)==0 ){
-        nColumn++;
+        if( whereLoopResize(pParse->db, pLoop, nColumn+1) ) return;
+        pLoop->aLTerm[nColumn++] = pTerm;
         idxCols |= cMask;
       }
     }
   }
   assert( nColumn>0 );
-  pLevel->plan.nEq = nColumn;
+  pLoop->u.btree.nEq = pLoop->nLTerm = nColumn;
+  pLoop->wsFlags = WHERE_COLUMN_EQ | WHERE_IDX_ONLY | WHERE_INDEXED
+                     | WHERE_AUTO_INDEX;
 
   /* Count the number of additional columns needed to create a
   ** covering index.  A "covering index" is an index that contains all
@@ -2008,17 +2156,17 @@ static void constructAutomaticIndex(
   ** original table changes and the index and table cannot both be used
   ** if they go out of sync.
   */
-  extraCols = pSrc->colUsed & (~idxCols | (((Bitmask)1)<<(BMS-1)));
+  extraCols = pSrc->colUsed & (~idxCols | MASKBIT(BMS-1));
   mxBitCol = (pTable->nCol >= BMS-1) ? BMS-1 : pTable->nCol;
   testcase( pTable->nCol==BMS-1 );
   testcase( pTable->nCol==BMS-2 );
   for(i=0; i<mxBitCol; i++){
-    if( extraCols & (((Bitmask)1)<<i) ) nColumn++;
+    if( extraCols & MASKBIT(i) ) nColumn++;
   }
-  if( pSrc->colUsed & (((Bitmask)1)<<(BMS-1)) ){
+  if( pSrc->colUsed & MASKBIT(BMS-1) ){
     nColumn += pTable->nCol - BMS + 1;
   }
-  pLevel->plan.wsFlags |= WHERE_COLUMN_EQ | WHERE_IDX_ONLY | WO_EQ;
+  pLoop->wsFlags |= WHERE_COLUMN_EQ | WHERE_IDX_ONLY;
 
   /* Construct the Index object to describe this index */
   nByte = sizeof(Index);
@@ -2027,7 +2175,7 @@ static void constructAutomaticIndex(
   nByte += nColumn;                 /* Index.aSortOrder */
   pIdx = sqlite3DbMallocZero(pParse->db, nByte);
   if( pIdx==0 ) return;
-  pLevel->plan.u.pIdx = pIdx;
+  pLoop->u.btree.pIndex = pIdx;
   pIdx->azColl = (char**)&pIdx[1];
   pIdx->aiColumn = (int*)&pIdx->azColl[nColumn];
   pIdx->aSortOrder = (u8*)&pIdx->aiColumn[nColumn];
@@ -2039,7 +2187,9 @@ static void constructAutomaticIndex(
   for(pTerm=pWC->a; pTerm<pWCEnd; pTerm++){
     if( termCanDriveIndex(pTerm, pSrc, notReady) ){
       int iCol = pTerm->u.leftColumn;
-      Bitmask cMask = iCol>=BMS ? ((Bitmask)1)<<(BMS-1) : ((Bitmask)1)<<iCol;
+      Bitmask cMask = iCol>=BMS ? MASKBIT(BMS-1) : MASKBIT(iCol);
+      testcase( iCol==BMS-1 );
+      testcase( iCol==BMS );
       if( (idxCols & cMask)==0 ){
         Expr *pX = pTerm->pExpr;
         idxCols |= cMask;
@@ -2050,18 +2200,18 @@ static void constructAutomaticIndex(
       }
     }
   }
-  assert( (u32)n==pLevel->plan.nEq );
+  assert( (u32)n==pLoop->u.btree.nEq );
 
   /* Add additional columns needed to make the automatic index into
   ** a covering index */
   for(i=0; i<mxBitCol; i++){
-    if( extraCols & (((Bitmask)1)<<i) ){
+    if( extraCols & MASKBIT(i) ){
       pIdx->aiColumn[n] = i;
       pIdx->azColl[n] = "BINARY";
       n++;
     }
   }
-  if( pSrc->colUsed & (((Bitmask)1)<<(BMS-1)) ){
+  if( pSrc->colUsed & MASKBIT(BMS-1) ){
     for(i=BMS-1; i<pTable->nCol; i++){
       pIdx->aiColumn[n] = i;
       pIdx->azColl[n] = "BINARY";
@@ -2073,6 +2223,7 @@ static void constructAutomaticIndex(
   /* Create the automatic index */
   pKeyinfo = sqlite3IndexKeyinfo(pParse, pIdx);
   assert( pLevel->iIdxCur>=0 );
+  pLevel->iIdxCur = pParse->nTab++;
   sqlite3VdbeAddOp4(v, OP_OpenAutoindex, pLevel->iIdxCur, nColumn+1, 0,
                     (char*)pKeyinfo, P4_KEYINFO_HANDOFF);
   VdbeComment((v, "for %s", pTable->zName));
@@ -2080,7 +2231,7 @@ static void constructAutomaticIndex(
   /* Fill the automatic index with content */
   addrTop = sqlite3VdbeAddOp1(v, OP_Rewind, pLevel->iTabCur);
   regRecord = sqlite3GetTempReg(pParse);
-  sqlite3GenerateIndexKey(pParse, pIdx, pLevel->iTabCur, regRecord, 1);
+  sqlite3GenerateIndexKey(pParse, pIdx, pLevel->iTabCur, regRecord, 1, 0);
   sqlite3VdbeAddOp2(v, OP_IdxInsert, pLevel->iIdxCur, regRecord);
   sqlite3VdbeChangeP5(v, OPFLAG_USESEEKRESULT);
   sqlite3VdbeAddOp2(v, OP_Next, pLevel->iTabCur, addrTop+1);
@@ -2099,11 +2250,12 @@ static void constructAutomaticIndex(
 ** responsibility of the caller to eventually release the structure
 ** by passing the pointer returned by this function to sqlite3_free().
 */
-static sqlite3_index_info *allocateIndexInfo(WhereBestIdx *p){
-  Parse *pParse = p->pParse; 
-  WhereClause *pWC = p->pWC;
-  struct SrcList_item *pSrc = p->pSrc;
-  ExprList *pOrderBy = p->pOrderBy;
+static sqlite3_index_info *allocateIndexInfo(
+  Parse *pParse,
+  WhereClause *pWC,
+  struct SrcList_item *pSrc,
+  ExprList *pOrderBy
+){
   int i, j;
   int nTerm;
   struct sqlite3_index_constraint *pIdxCons;
@@ -2113,8 +2265,6 @@ static sqlite3_index_info *allocateIndexInfo(WhereBestIdx *p){
   int nOrderBy;
   sqlite3_index_info *pIdxInfo;
 
-  WHERETRACE(("Recomputing index info for %s...\n", pSrc->pTab->zName));
-
   /* Count the number of possible WHERE clause constraints referring
   ** to this virtual table */
   for(i=nTerm=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){
@@ -2150,7 +2300,6 @@ static sqlite3_index_info *allocateIndexInfo(WhereBestIdx *p){
                            + sizeof(*pIdxOrderBy)*nOrderBy );
   if( pIdxInfo==0 ){
     sqlite3ErrorMsg(pParse, "out of memory");
-    /* (double)0 In case of SQLITE_OMIT_FLOATING_POINT... */
     return 0;
   }
 
@@ -2206,8 +2355,8 @@ static sqlite3_index_info *allocateIndexInfo(WhereBestIdx *p){
 /*
 ** The table object reference passed as the second argument to this function
 ** must represent a virtual table. This function invokes the xBestIndex()
-** method of the virtual table with the sqlite3_index_info pointer passed
-** as the argument.
+** method of the virtual table with the sqlite3_index_info object that
+** comes in as the 3rd argument to this function.
 **
 ** If an error occurs, pParse is populated with an error message and a
 ** non-zero value is returned. Otherwise, 0 is returned and the output
@@ -2222,7 +2371,6 @@ static int vtabBestIndex(Parse *pParse, Table *pTab, sqlite3_index_info *p){
   int i;
   int rc;
 
-  WHERETRACE(("xBestIndex for %s\n", pTab->zName));
   TRACE_IDX_INPUTS(p);
   rc = pVtab->pModule->xBestIndex(pVtab, p);
   TRACE_IDX_OUTPUTS(p);
@@ -2248,208 +2396,9 @@ static int vtabBestIndex(Parse *pParse, Table *pTab, sqlite3_index_info *p){
 
   return pParse->nErr;
 }
+#endif /* !defined(SQLITE_OMIT_VIRTUALTABLE) */
 
 
-/*
-** Compute the best index for a virtual table.
-**
-** The best index is computed by the xBestIndex method of the virtual
-** table module.  This routine is really just a wrapper that sets up
-** the sqlite3_index_info structure that is used to communicate with
-** xBestIndex.
-**
-** In a join, this routine might be called multiple times for the
-** same virtual table.  The sqlite3_index_info structure is created
-** and initialized on the first invocation and reused on all subsequent
-** invocations.  The sqlite3_index_info structure is also used when
-** code is generated to access the virtual table.  The whereInfoDelete() 
-** routine takes care of freeing the sqlite3_index_info structure after
-** everybody has finished with it.
-*/
-static void bestVirtualIndex(WhereBestIdx *p){
-  Parse *pParse = p->pParse;      /* The parsing context */
-  WhereClause *pWC = p->pWC;      /* The WHERE clause */
-  struct SrcList_item *pSrc = p->pSrc; /* The FROM clause term to search */
-  Table *pTab = pSrc->pTab;
-  sqlite3_index_info *pIdxInfo;
-  struct sqlite3_index_constraint *pIdxCons;
-  struct sqlite3_index_constraint_usage *pUsage;
-  WhereTerm *pTerm;
-  int i, j;
-  int nOrderBy;
-  int bAllowIN;                   /* Allow IN optimizations */
-  double rCost;
-
-  /* Make sure wsFlags is initialized to some sane value. Otherwise, if the 
-  ** malloc in allocateIndexInfo() fails and this function returns leaving
-  ** wsFlags in an uninitialized state, the caller may behave unpredictably.
-  */
-  memset(&p->cost, 0, sizeof(p->cost));
-  p->cost.plan.wsFlags = WHERE_VIRTUALTABLE;
-
-  /* If the sqlite3_index_info structure has not been previously
-  ** allocated and initialized, then allocate and initialize it now.
-  */
-  pIdxInfo = *p->ppIdxInfo;
-  if( pIdxInfo==0 ){
-    *p->ppIdxInfo = pIdxInfo = allocateIndexInfo(p);
-  }
-  if( pIdxInfo==0 ){
-    return;
-  }
-
-  /* At this point, the sqlite3_index_info structure that pIdxInfo points
-  ** to will have been initialized, either during the current invocation or
-  ** during some prior invocation.  Now we just have to customize the
-  ** details of pIdxInfo for the current invocation and pass it to
-  ** xBestIndex.
-  */
-
-  /* The module name must be defined. Also, by this point there must
-  ** be a pointer to an sqlite3_vtab structure. Otherwise
-  ** sqlite3ViewGetColumnNames() would have picked up the error. 
-  */
-  assert( pTab->azModuleArg && pTab->azModuleArg[0] );
-  assert( sqlite3GetVTable(pParse->db, pTab) );
-
-  /* Try once or twice.  On the first attempt, allow IN optimizations.
-  ** If an IN optimization is accepted by the virtual table xBestIndex
-  ** method, but the  pInfo->aConstrainUsage.omit flag is not set, then
-  ** the query will not work because it might allow duplicate rows in
-  ** output.  In that case, run the xBestIndex method a second time
-  ** without the IN constraints.  Usually this loop only runs once.
-  ** The loop will exit using a "break" statement.
-  */
-  for(bAllowIN=1; 1; bAllowIN--){
-    assert( bAllowIN==0 || bAllowIN==1 );
-
-    /* Set the aConstraint[].usable fields and initialize all 
-    ** output variables to zero.
-    **
-    ** aConstraint[].usable is true for constraints where the right-hand
-    ** side contains only references to tables to the left of the current
-    ** table.  In other words, if the constraint is of the form:
-    **
-    **           column = expr
-    **
-    ** and we are evaluating a join, then the constraint on column is 
-    ** only valid if all tables referenced in expr occur to the left
-    ** of the table containing column.
-    **
-    ** The aConstraints[] array contains entries for all constraints
-    ** on the current table.  That way we only have to compute it once
-    ** even though we might try to pick the best index multiple times.
-    ** For each attempt at picking an index, the order of tables in the
-    ** join might be different so we have to recompute the usable flag
-    ** each time.
-    */
-    pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
-    pUsage = pIdxInfo->aConstraintUsage;
-    for(i=0; i<pIdxInfo->nConstraint; i++, pIdxCons++){
-      j = pIdxCons->iTermOffset;
-      pTerm = &pWC->a[j];
-      if( (pTerm->prereqRight&p->notReady)==0
-       && (bAllowIN || (pTerm->eOperator & WO_IN)==0)
-      ){
-        pIdxCons->usable = 1;
-      }else{
-        pIdxCons->usable = 0;
-      }
-    }
-    memset(pUsage, 0, sizeof(pUsage[0])*pIdxInfo->nConstraint);
-    if( pIdxInfo->needToFreeIdxStr ){
-      sqlite3_free(pIdxInfo->idxStr);
-    }
-    pIdxInfo->idxStr = 0;
-    pIdxInfo->idxNum = 0;
-    pIdxInfo->needToFreeIdxStr = 0;
-    pIdxInfo->orderByConsumed = 0;
-    /* ((double)2) In case of SQLITE_OMIT_FLOATING_POINT... */
-    pIdxInfo->estimatedCost = SQLITE_BIG_DBL / ((double)2);
-    nOrderBy = pIdxInfo->nOrderBy;
-    if( !p->pOrderBy ){
-      pIdxInfo->nOrderBy = 0;
-    }
-  
-    if( vtabBestIndex(pParse, pTab, pIdxInfo) ){
-      return;
-    }
-  
-    pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
-    for(i=0; i<pIdxInfo->nConstraint; i++, pIdxCons++){
-      if( pUsage[i].argvIndex>0 ){
-        j = pIdxCons->iTermOffset;
-        pTerm = &pWC->a[j];
-        p->cost.used |= pTerm->prereqRight;
-        if( (pTerm->eOperator & WO_IN)!=0 ){
-          if( pUsage[i].omit==0 ){
-            /* Do not attempt to use an IN constraint if the virtual table
-            ** says that the equivalent EQ constraint cannot be safely omitted.
-            ** If we do attempt to use such a constraint, some rows might be
-            ** repeated in the output. */
-            break;
-          }
-          /* A virtual table that is constrained by an IN clause may not
-          ** consume the ORDER BY clause because (1) the order of IN terms
-          ** is not necessarily related to the order of output terms and
-          ** (2) Multiple outputs from a single IN value will not merge
-          ** together.  */
-          pIdxInfo->orderByConsumed = 0;
-        }
-      }
-    }
-    if( i>=pIdxInfo->nConstraint ) break;
-  }
-
-  /* The orderByConsumed signal is only valid if all outer loops collectively
-  ** generate just a single row of output.
-  */
-  if( pIdxInfo->orderByConsumed ){
-    for(i=0; i<p->i; i++){
-      if( (p->aLevel[i].plan.wsFlags & WHERE_UNIQUE)==0 ){
-        pIdxInfo->orderByConsumed = 0;
-      }
-    }
-  }
-  
-  /* If there is an ORDER BY clause, and the selected virtual table index
-  ** does not satisfy it, increase the cost of the scan accordingly. This
-  ** matches the processing for non-virtual tables in bestBtreeIndex().
-  */
-  rCost = pIdxInfo->estimatedCost;
-  if( p->pOrderBy && pIdxInfo->orderByConsumed==0 ){
-    rCost += estLog(rCost)*rCost;
-  }
-
-  /* The cost is not allowed to be larger than SQLITE_BIG_DBL (the
-  ** inital value of lowestCost in this loop. If it is, then the
-  ** (cost<lowestCost) test below will never be true.
-  ** 
-  ** Use "(double)2" instead of "2.0" in case OMIT_FLOATING_POINT 
-  ** is defined.
-  */
-  if( (SQLITE_BIG_DBL/((double)2))<rCost ){
-    p->cost.rCost = (SQLITE_BIG_DBL/((double)2));
-  }else{
-    p->cost.rCost = rCost;
-  }
-  p->cost.plan.u.pVtabIdx = pIdxInfo;
-  if( pIdxInfo->orderByConsumed ){
-    p->cost.plan.wsFlags |= WHERE_ORDERED;
-    p->cost.plan.nOBSat = nOrderBy;
-  }else{
-    p->cost.plan.nOBSat = p->i ? p->aLevel[p->i-1].plan.nOBSat : 0;
-  }
-  p->cost.plan.nEq = 0;
-  pIdxInfo->nOrderBy = nOrderBy;
-
-  /* Try to find a more efficient access pattern by using multiple indexes
-  ** to optimize an OR expression within the WHERE clause. 
-  */
-  bestOrClauseIndex(p);
-}
-#endif /* SQLITE_OMIT_VIRTUALTABLE */
-
 #ifdef SQLITE_ENABLE_STAT3
 /*
 ** Estimate the location of a particular key among all keys in an
@@ -2535,9 +2484,10 @@ static int whereKeyStats(
         assert( pColl->enc==SQLITE_UTF8 );
       }else{
         pColl = sqlite3GetCollSeq(pParse, SQLITE_UTF8, 0, *pIdx->azColl);
-        if( pColl==0 ){
-          return SQLITE_ERROR;
-        }
+        /* If the collating sequence was unavailable, we should have failed
+        ** long ago and never reached this point.  But we'll check just to
+        ** be doubly sure. */
+        if( NEVER(pColl==0) ) return SQLITE_ERROR;
         z = (const u8 *)sqlite3ValueText(pVal, pColl->enc);
         if( !z ){
           return SQLITE_NOMEM;
@@ -2638,7 +2588,7 @@ static int valueFromExpr(
   ){
     int iVar = pExpr->iColumn;
     sqlite3VdbeSetVarmask(pParse->pVdbe, iVar);
-    *pp = sqlite3VdbeGetValue(pParse->pReprepare, iVar, aff);
+    *pp = sqlite3VdbeGetBoundValue(pParse->pReprepare, iVar, aff);
     return SQLITE_OK;
   }
   return sqlite3ValueFromExpr(pParse->db, pExpr, SQLITE_UTF8, aff, pp);
@@ -2690,13 +2640,13 @@ static int whereRangeScanEst(
   int nEq,             /* index into p->aCol[] of the range-compared column */
   WhereTerm *pLower,   /* Lower bound on the range. ex: "x>123" Might be NULL */
   WhereTerm *pUpper,   /* Upper bound on the range. ex: "x<455" Might be NULL */
-  double *pRangeDiv   /* OUT: Reduce search space by this divisor */
+  WhereCost *pRangeDiv /* OUT: Reduce search space by this divisor */
 ){
   int rc = SQLITE_OK;
 
 #ifdef SQLITE_ENABLE_STAT3
 
-  if( nEq==0 && p->nSample ){
+  if( nEq==0 && p->nSample && OptimizationEnabled(pParse->db, SQLITE_Stat3) ){
     sqlite3_value *pRangeVal;
     tRowcnt iLower = 0;
     tRowcnt iUpper = p->aiRowEst[0];
@@ -2728,13 +2678,13 @@ static int whereRangeScanEst(
       sqlite3ValueFree(pRangeVal);
     }
     if( rc==SQLITE_OK ){
-      if( iUpper<=iLower ){
-        *pRangeDiv = (double)p->aiRowEst[0];
-      }else{
-        *pRangeDiv = (double)p->aiRowEst[0]/(double)(iUpper - iLower);
+      WhereCost iBase = whereCost(p->aiRowEst[0]);
+      if( iUpper>iLower ){
+        iBase -= whereCost(iUpper - iLower);
       }
-      WHERETRACE(("range scan regions: %u..%u  div=%g\n",
-                  (u32)iLower, (u32)iUpper, *pRangeDiv));
+      *pRangeDiv = iBase;
+      WHERETRACE(0x100, ("range scan regions: %u..%u  div=%d\n",
+                         (u32)iLower, (u32)iUpper, *pRangeDiv));
       return SQLITE_OK;
     }
   }
@@ -2744,9 +2694,15 @@ static int whereRangeScanEst(
   UNUSED_PARAMETER(nEq);
 #endif
   assert( pLower || pUpper );
-  *pRangeDiv = (double)1;
-  if( pLower && (pLower->wtFlags & TERM_VNULL)==0 ) *pRangeDiv *= (double)4;
-  if( pUpper ) *pRangeDiv *= (double)4;
+  *pRangeDiv = 0;
+  /* TUNING:  Each inequality constraint reduces the search space 4-fold.
+  ** A BETWEEN operator, therefore, reduces the search space 16-fold */
+  if( pLower && (pLower->wtFlags & TERM_VNULL)==0 ){
+    *pRangeDiv += 20;  assert( 20==whereCost(4) );
+  }
+  if( pUpper ){
+    *pRangeDiv += 20;  assert( 20==whereCost(4) );
+  }
   return rc;
 }
 
@@ -2772,7 +2728,7 @@ static int whereEqualScanEst(
   Parse *pParse,       /* Parsing & code generating context */
   Index *p,            /* The index whose left-most column is pTerm */
   Expr *pExpr,         /* Expression for VALUE in the x=VALUE constraint */
-  double *pnRow        /* Write the revised row estimate here */
+  tRowcnt *pnRow       /* Write the revised row estimate here */
 ){
   sqlite3_value *pRhs = 0;  /* VALUE on right-hand side of pTerm */
   u8 aff;                   /* Column affinity */
@@ -2791,7 +2747,7 @@ static int whereEqualScanEst(
   if( pRhs==0 ) return SQLITE_NOTFOUND;
   rc = whereKeyStats(pParse, p, pRhs, 0, a);
   if( rc==SQLITE_OK ){
-    WHERETRACE(("equality scan regions: %d\n", (int)a[1]));
+    WHERETRACE(0x100,("equality scan regions: %d\n", (int)a[1]));
     *pnRow = a[1];
   }
 whereEqualScanEst_cancel:
@@ -2821,12 +2777,12 @@ static int whereInScanEst(
   Parse *pParse,       /* Parsing & code generating context */
   Index *p,            /* The index whose left-most column is pTerm */
   ExprList *pList,     /* The value list on the RHS of "x IN (v1,v2,v3,...)" */
-  double *pnRow        /* Write the revised row estimate here */
+  tRowcnt *pnRow       /* Write the revised row estimate here */
 ){
-  int rc = SQLITE_OK;         /* Subfunction return code */
-  double nEst;                /* Number of rows for a single term */
-  double nRowEst = (double)0; /* New estimate of the number of rows */
-  int i;                      /* Loop counter */
+  int rc = SQLITE_OK;     /* Subfunction return code */
+  tRowcnt nEst;           /* Number of rows for a single term */
+  tRowcnt nRowEst = 0;    /* New estimate of the number of rows */
+  int i;                  /* Loop counter */
 
   assert( p->aSample!=0 );
   for(i=0; rc==SQLITE_OK && i<pList->nExpr; i++){
@@ -2837,886 +2793,13 @@ static int whereInScanEst(
   if( rc==SQLITE_OK ){
     if( nRowEst > p->aiRowEst[0] ) nRowEst = p->aiRowEst[0];
     *pnRow = nRowEst;
-    WHERETRACE(("IN row estimate: est=%g\n", nRowEst));
+    WHERETRACE(0x100,("IN row estimate: est=%g\n", nRowEst));
   }
   return rc;
 }
 #endif /* defined(SQLITE_ENABLE_STAT3) */
 
 /*
-** Check to see if column iCol of the table with cursor iTab will appear
-** in sorted order according to the current query plan.
-**
-** Return values:
-**
-**    0   iCol is not ordered
-**    1   iCol has only a single value
-**    2   iCol is in ASC order
-**    3   iCol is in DESC order
-*/
-static int isOrderedColumn(
-  WhereBestIdx *p,
-  int iTab,
-  int iCol
-){
-  int i, j;
-  WhereLevel *pLevel = &p->aLevel[p->i-1];
-  Index *pIdx;
-  u8 sortOrder;
-  for(i=p->i-1; i>=0; i--, pLevel--){
-    if( pLevel->iTabCur!=iTab ) continue;
-    if( (pLevel->plan.wsFlags & WHERE_ALL_UNIQUE)!=0 ){
-      return 1;
-    }
-    assert( (pLevel->plan.wsFlags & WHERE_ORDERED)!=0 );
-    if( (pIdx = pLevel->plan.u.pIdx)!=0 ){
-      if( iCol<0 ){
-        sortOrder = 0;
-        testcase( (pLevel->plan.wsFlags & WHERE_REVERSE)!=0 );
-      }else{
-        int n = pIdx->nColumn;
-        for(j=0; j<n; j++){
-          if( iCol==pIdx->aiColumn[j] ) break;
-        }
-        if( j>=n ) return 0;
-        sortOrder = pIdx->aSortOrder[j];
-        testcase( (pLevel->plan.wsFlags & WHERE_REVERSE)!=0 );
-      }
-    }else{
-      if( iCol!=(-1) ) return 0;
-      sortOrder = 0;
-      testcase( (pLevel->plan.wsFlags & WHERE_REVERSE)!=0 );
-    }
-    if( (pLevel->plan.wsFlags & WHERE_REVERSE)!=0 ){
-      assert( sortOrder==0 || sortOrder==1 );
-      testcase( sortOrder==1 );
-      sortOrder = 1 - sortOrder;
-    }
-    return sortOrder+2;
-  }
-  return 0;
-}
-
-/*
-** This routine decides if pIdx can be used to satisfy the ORDER BY
-** clause, either in whole or in part.  The return value is the 
-** cumulative number of terms in the ORDER BY clause that are satisfied
-** by the index pIdx and other indices in outer loops.
-**
-** The table being queried has a cursor number of "base".  pIdx is the
-** index that is postulated for use to access the table.
-**
-** The *pbRev value is set to 0 order 1 depending on whether or not
-** pIdx should be run in the forward order or in reverse order.
-*/
-static int isSortingIndex(
-  WhereBestIdx *p,    /* Best index search context */
-  Index *pIdx,        /* The index we are testing */
-  int base,           /* Cursor number for the table to be sorted */
-  int *pbRev,         /* Set to 1 for reverse-order scan of pIdx */
-  int *pbObUnique     /* ORDER BY column values will different in every row */
-){
-  int i;                        /* Number of pIdx terms used */
-  int j;                        /* Number of ORDER BY terms satisfied */
-  int sortOrder = 2;            /* 0: forward.  1: backward.  2: unknown */
-  int nTerm;                    /* Number of ORDER BY terms */
-  struct ExprList_item *pOBItem;/* A term of the ORDER BY clause */
-  Table *pTab = pIdx->pTable;   /* Table that owns index pIdx */
-  ExprList *pOrderBy;           /* The ORDER BY clause */
-  Parse *pParse = p->pParse;    /* Parser context */
-  sqlite3 *db = pParse->db;     /* Database connection */
-  int nPriorSat;                /* ORDER BY terms satisfied by outer loops */
-  int seenRowid = 0;            /* True if an ORDER BY rowid term is seen */
-  int uniqueNotNull;            /* pIdx is UNIQUE with all terms are NOT NULL */
-  int outerObUnique;            /* Outer loops generate different values in
-                                ** every row for the ORDER BY columns */
-
-  if( p->i==0 ){
-    nPriorSat = 0;
-    outerObUnique = 1;
-  }else{
-    u32 wsFlags = p->aLevel[p->i-1].plan.wsFlags;
-    nPriorSat = p->aLevel[p->i-1].plan.nOBSat;
-    if( (wsFlags & WHERE_ORDERED)==0 ){
-      /* This loop cannot be ordered unless the next outer loop is
-      ** also ordered */
-      return nPriorSat;
-    }
-    if( OptimizationDisabled(db, SQLITE_OrderByIdxJoin) ){
-      /* Only look at the outer-most loop if the OrderByIdxJoin
-      ** optimization is disabled */
-      return nPriorSat;
-    }
-    testcase( wsFlags & WHERE_OB_UNIQUE );
-    testcase( wsFlags & WHERE_ALL_UNIQUE );
-    outerObUnique = (wsFlags & (WHERE_OB_UNIQUE|WHERE_ALL_UNIQUE))!=0;
-  }
-  pOrderBy = p->pOrderBy;
-  assert( pOrderBy!=0 );
-  if( pIdx->bUnordered ){
-    /* Hash indices (indicated by the "unordered" tag on sqlite_stat1) cannot
-    ** be used for sorting */
-    return nPriorSat;
-  }
-  nTerm = pOrderBy->nExpr;
-  uniqueNotNull = pIdx->onError!=OE_None;
-  assert( nTerm>0 );
-
-  /* Argument pIdx must either point to a 'real' named index structure, 
-  ** or an index structure allocated on the stack by bestBtreeIndex() to
-  ** represent the rowid index that is part of every table.  */
-  assert( pIdx->zName || (pIdx->nColumn==1 && pIdx->aiColumn[0]==-1) );
-
-  /* Match terms of the ORDER BY clause against columns of
-  ** the index.
-  **
-  ** Note that indices have pIdx->nColumn regular columns plus
-  ** one additional column containing the rowid.  The rowid column
-  ** of the index is also allowed to match against the ORDER BY
-  ** clause.
-  */
-  j = nPriorSat;
-  for(i=0,pOBItem=&pOrderBy->a[j]; j<nTerm && i<=pIdx->nColumn; i++){
-    Expr *pOBExpr;          /* The expression of the ORDER BY pOBItem */
-    CollSeq *pColl;         /* The collating sequence of pOBExpr */
-    int termSortOrder;      /* Sort order for this term */
-    int iColumn;            /* The i-th column of the index.  -1 for rowid */
-    int iSortOrder;         /* 1 for DESC, 0 for ASC on the i-th index term */
-    int isEq;               /* Subject to an == or IS NULL constraint */
-    int isMatch;            /* ORDER BY term matches the index term */
-    const char *zColl;      /* Name of collating sequence for i-th index term */
-    WhereTerm *pConstraint; /* A constraint in the WHERE clause */
-
-    /* If the next term of the ORDER BY clause refers to anything other than
-    ** a column in the "base" table, then this index will not be of any
-    ** further use in handling the ORDER BY. */
-    pOBExpr = sqlite3ExprSkipCollate(pOBItem->pExpr);
-    if( pOBExpr->op!=TK_COLUMN || pOBExpr->iTable!=base ){
-      break;
-    }
-
-    /* Find column number and collating sequence for the next entry
-    ** in the index */
-    if( pIdx->zName && i<pIdx->nColumn ){
-      iColumn = pIdx->aiColumn[i];
-      if( iColumn==pIdx->pTable->iPKey ){
-        iColumn = -1;
-      }
-      iSortOrder = pIdx->aSortOrder[i];
-      zColl = pIdx->azColl[i];
-      assert( zColl!=0 );
-    }else{
-      iColumn = -1;
-      iSortOrder = 0;
-      zColl = 0;
-    }
-
-    /* Check to see if the column number and collating sequence of the
-    ** index match the column number and collating sequence of the ORDER BY
-    ** clause entry.  Set isMatch to 1 if they both match. */
-    if( pOBExpr->iColumn==iColumn ){
-      if( zColl ){
-        pColl = sqlite3ExprCollSeq(pParse, pOBItem->pExpr);
-        if( !pColl ) pColl = db->pDfltColl;
-        isMatch = sqlite3StrICmp(pColl->zName, zColl)==0;
-      }else{
-        isMatch = 1;
-      }
-    }else{
-      isMatch = 0;
-    }
-
-    /* termSortOrder is 0 or 1 for whether or not the access loop should
-    ** run forward or backwards (respectively) in order to satisfy this 
-    ** term of the ORDER BY clause. */
-    assert( pOBItem->sortOrder==0 || pOBItem->sortOrder==1 );
-    assert( iSortOrder==0 || iSortOrder==1 );
-    termSortOrder = iSortOrder ^ pOBItem->sortOrder;
-
-    /* If X is the column in the index and ORDER BY clause, check to see
-    ** if there are any X= or X IS NULL constraints in the WHERE clause. */
-    pConstraint = findTerm(p->pWC, base, iColumn, p->notReady,
-                           WO_EQ|WO_ISNULL|WO_IN, pIdx);
-    if( pConstraint==0 ){
-      isEq = 0;
-    }else if( (pConstraint->eOperator & WO_IN)!=0 ){
-      isEq = 0;
-    }else if( (pConstraint->eOperator & WO_ISNULL)!=0 ){
-      uniqueNotNull = 0;
-      isEq = 1;  /* "X IS NULL" means X has only a single value */
-    }else if( pConstraint->prereqRight==0 ){
-      isEq = 1;  /* Constraint "X=constant" means X has only a single value */
-    }else{
-      Expr *pRight = pConstraint->pExpr->pRight;
-      if( pRight->op==TK_COLUMN ){
-        WHERETRACE(("       .. isOrderedColumn(tab=%d,col=%d)",
-                    pRight->iTable, pRight->iColumn));
-        isEq = isOrderedColumn(p, pRight->iTable, pRight->iColumn);
-        WHERETRACE((" -> isEq=%d\n", isEq));
-
-        /* If the constraint is of the form X=Y where Y is an ordered value
-        ** in an outer loop, then make sure the sort order of Y matches the
-        ** sort order required for X. */
-        if( isMatch && isEq>=2 && isEq!=pOBItem->sortOrder+2 ){
-          testcase( isEq==2 );
-          testcase( isEq==3 );
-          break;
-        }
-      }else{
-        isEq = 0;  /* "X=expr" places no ordering constraints on X */
-      }
-    }
-    if( !isMatch ){
-      if( isEq==0 ){
-        break;
-      }else{
-        continue;
-      }
-    }else if( isEq!=1 ){
-      if( sortOrder==2 ){
-        sortOrder = termSortOrder;
-      }else if( termSortOrder!=sortOrder ){
-        break;
-      }
-    }
-    j++;
-    pOBItem++;
-    if( iColumn<0 ){
-      seenRowid = 1;
-      break;
-    }else if( pTab->aCol[iColumn].notNull==0 && isEq!=1 ){
-      testcase( isEq==0 );
-      testcase( isEq==2 );
-      testcase( isEq==3 );
-      uniqueNotNull = 0;
-    }
-  }
-  if( seenRowid ){
-    uniqueNotNull = 1;
-  }else if( uniqueNotNull==0 || i<pIdx->nColumn ){
-    uniqueNotNull = 0;
-  }
-
-  /* If we have not found at least one ORDER BY term that matches the
-  ** index, then show no progress. */
-  if( pOBItem==&pOrderBy->a[nPriorSat] ) return nPriorSat;
-
-  /* Either the outer queries must generate rows where there are no two
-  ** rows with the same values in all ORDER BY columns, or else this
-  ** loop must generate just a single row of output.  Example:  Suppose
-  ** the outer loops generate A=1 and A=1, and this loop generates B=3
-  ** and B=4.  Then without the following test, ORDER BY A,B would 
-  ** generate the wrong order output: 1,3 1,4 1,3 1,4
-  */
-  if( outerObUnique==0 && uniqueNotNull==0 ) return nPriorSat;
-  *pbObUnique = uniqueNotNull;
-
-  /* Return the necessary scan order back to the caller */
-  *pbRev = sortOrder & 1;
-
-  /* If there was an "ORDER BY rowid" term that matched, or it is only
-  ** possible for a single row from this table to match, then skip over
-  ** any additional ORDER BY terms dealing with this table.
-  */
-  if( uniqueNotNull ){
-    /* Advance j over additional ORDER BY terms associated with base */
-    WhereMaskSet *pMS = p->pWC->pMaskSet;
-    Bitmask m = ~getMask(pMS, base);
-    while( j<nTerm && (exprTableUsage(pMS, pOrderBy->a[j].pExpr)&m)==0 ){
-      j++;
-    }
-  }
-  return j;
-}
-
-/*
-** Find the best query plan for accessing a particular table.  Write the
-** best query plan and its cost into the p->cost.
-**
-** The lowest cost plan wins.  The cost is an estimate of the amount of
-** CPU and disk I/O needed to process the requested result.
-** Factors that influence cost include:
-**
-**    *  The estimated number of rows that will be retrieved.  (The
-**       fewer the better.)
-**
-**    *  Whether or not sorting must occur.
-**
-**    *  Whether or not there must be separate lookups in the
-**       index and in the main table.
-**
-** If there was an INDEXED BY clause (pSrc->pIndex) attached to the table in
-** the SQL statement, then this function only considers plans using the 
-** named index. If no such plan is found, then the returned cost is
-** SQLITE_BIG_DBL. If a plan is found that uses the named index, 
-** then the cost is calculated in the usual way.
-**
-** If a NOT INDEXED clause was attached to the table 
-** in the SELECT statement, then no indexes are considered. However, the 
-** selected plan may still take advantage of the built-in rowid primary key
-** index.
-*/
-static void bestBtreeIndex(WhereBestIdx *p){
-  Parse *pParse = p->pParse;  /* The parsing context */
-  WhereClause *pWC = p->pWC;  /* The WHERE clause */
-  struct SrcList_item *pSrc = p->pSrc; /* The FROM clause term to search */
-  int iCur = pSrc->iCursor;   /* The cursor of the table to be accessed */
-  Index *pProbe;              /* An index we are evaluating */
-  Index *pIdx;                /* Copy of pProbe, or zero for IPK index */
-  int eqTermMask;             /* Current mask of valid equality operators */
-  int idxEqTermMask;          /* Index mask of valid equality operators */
-  Index sPk;                  /* A fake index object for the primary key */
-  tRowcnt aiRowEstPk[2];      /* The aiRowEst[] value for the sPk index */
-  int aiColumnPk = -1;        /* The aColumn[] value for the sPk index */
-  int wsFlagMask;             /* Allowed flags in p->cost.plan.wsFlag */
-  int nPriorSat;              /* ORDER BY terms satisfied by outer loops */
-  int nOrderBy;               /* Number of ORDER BY terms */
-  char bSortInit;             /* Initializer for bSort in inner loop */
-  char bDistInit;             /* Initializer for bDist in inner loop */
-
-
-  /* Initialize the cost to a worst-case value */
-  memset(&p->cost, 0, sizeof(p->cost));
-  p->cost.rCost = SQLITE_BIG_DBL;
-
-  /* If the pSrc table is the right table of a LEFT JOIN then we may not
-  ** use an index to satisfy IS NULL constraints on that table.  This is
-  ** because columns might end up being NULL if the table does not match -
-  ** a circumstance which the index cannot help us discover.  Ticket #2177.
-  */
-  if( pSrc->jointype & JT_LEFT ){
-    idxEqTermMask = WO_EQ|WO_IN;
-  }else{
-    idxEqTermMask = WO_EQ|WO_IN|WO_ISNULL;
-  }
-
-  if( pSrc->pIndex ){
-    /* An INDEXED BY clause specifies a particular index to use */
-    pIdx = pProbe = pSrc->pIndex;
-    wsFlagMask = ~(WHERE_ROWID_EQ|WHERE_ROWID_RANGE);
-    eqTermMask = idxEqTermMask;
-  }else{
-    /* There is no INDEXED BY clause.  Create a fake Index object in local
-    ** variable sPk to represent the rowid primary key index.  Make this
-    ** fake index the first in a chain of Index objects with all of the real
-    ** indices to follow */
-    Index *pFirst;                  /* First of real indices on the table */
-    memset(&sPk, 0, sizeof(Index));
-    sPk.nColumn = 1;
-    sPk.aiColumn = &aiColumnPk;
-    sPk.aiRowEst = aiRowEstPk;
-    sPk.onError = OE_Replace;
-    sPk.pTable = pSrc->pTab;
-    aiRowEstPk[0] = pSrc->pTab->nRowEst;
-    aiRowEstPk[1] = 1;
-    pFirst = pSrc->pTab->pIndex;
-    if( pSrc->notIndexed==0 ){
-      /* The real indices of the table are only considered if the
-      ** NOT INDEXED qualifier is omitted from the FROM clause */
-      sPk.pNext = pFirst;
-    }
-    pProbe = &sPk;
-    wsFlagMask = ~(
-        WHERE_COLUMN_IN|WHERE_COLUMN_EQ|WHERE_COLUMN_NULL|WHERE_COLUMN_RANGE
-    );
-    eqTermMask = WO_EQ|WO_IN;
-    pIdx = 0;
-  }
-
-  nOrderBy = p->pOrderBy ? p->pOrderBy->nExpr : 0;
-  if( p->i ){
-    nPriorSat = p->aLevel[p->i-1].plan.nOBSat;
-    bSortInit = nPriorSat<nOrderBy;
-    bDistInit = 0;
-  }else{
-    nPriorSat = 0;
-    bSortInit = nOrderBy>0;
-    bDistInit = p->pDistinct!=0;
-  }
-
-  /* Loop over all indices looking for the best one to use
-  */
-  for(; pProbe; pIdx=pProbe=pProbe->pNext){
-    const tRowcnt * const aiRowEst = pProbe->aiRowEst;
-    WhereCost pc;               /* Cost of using pProbe */
-    double log10N = (double)1;  /* base-10 logarithm of nRow (inexact) */
-
-    /* The following variables are populated based on the properties of
-    ** index being evaluated. They are then used to determine the expected
-    ** cost and number of rows returned.
-    **
-    **  pc.plan.nEq: 
-    **    Number of equality terms that can be implemented using the index.
-    **    In other words, the number of initial fields in the index that
-    **    are used in == or IN or NOT NULL constraints of the WHERE clause.
-    **
-    **  nInMul:  
-    **    The "in-multiplier". This is an estimate of how many seek operations 
-    **    SQLite must perform on the index in question. For example, if the 
-    **    WHERE clause is:
-    **
-    **      WHERE a IN (1, 2, 3) AND b IN (4, 5, 6)
-    **
-    **    SQLite must perform 9 lookups on an index on (a, b), so nInMul is 
-    **    set to 9. Given the same schema and either of the following WHERE 
-    **    clauses:
-    **
-    **      WHERE a =  1
-    **      WHERE a >= 2
-    **
-    **    nInMul is set to 1.
-    **
-    **    If there exists a WHERE term of the form "x IN (SELECT ...)", then 
-    **    the sub-select is assumed to return 25 rows for the purposes of 
-    **    determining nInMul.
-    **
-    **  bInEst:  
-    **    Set to true if there was at least one "x IN (SELECT ...)" term used 
-    **    in determining the value of nInMul.  Note that the RHS of the
-    **    IN operator must be a SELECT, not a value list, for this variable
-    **    to be true.
-    **
-    **  rangeDiv:
-    **    An estimate of a divisor by which to reduce the search space due
-    **    to inequality constraints.  In the absence of sqlite_stat3 ANALYZE
-    **    data, a single inequality reduces the search space to 1/4rd its
-    **    original size (rangeDiv==4).  Two inequalities reduce the search
-    **    space to 1/16th of its original size (rangeDiv==16).
-    **
-    **  bSort:   
-    **    Boolean. True if there is an ORDER BY clause that will require an 
-    **    external sort (i.e. scanning the index being evaluated will not 
-    **    correctly order records).
-    **
-    **  bDist:
-    **    Boolean. True if there is a DISTINCT clause that will require an 
-    **    external btree.
-    **
-    **  bLookup: 
-    **    Boolean. True if a table lookup is required for each index entry
-    **    visited.  In other words, true if this is not a covering index.
-    **    This is always false for the rowid primary key index of a table.
-    **    For other indexes, it is true unless all the columns of the table
-    **    used by the SELECT statement are present in the index (such an
-    **    index is sometimes described as a covering index).
-    **    For example, given the index on (a, b), the second of the following 
-    **    two queries requires table b-tree lookups in order to find the value
-    **    of column c, but the first does not because columns a and b are
-    **    both available in the index.
-    **
-    **             SELECT a, b    FROM tbl WHERE a = 1;
-    **             SELECT a, b, c FROM tbl WHERE a = 1;
-    */
-    int bInEst = 0;               /* True if "x IN (SELECT...)" seen */
-    int nInMul = 1;               /* Number of distinct equalities to lookup */
-    double rangeDiv = (double)1;  /* Estimated reduction in search space */
-    int nBound = 0;               /* Number of range constraints seen */
-    char bSort = bSortInit;       /* True if external sort required */
-    char bDist = bDistInit;       /* True if index cannot help with DISTINCT */
-    char bLookup = 0;             /* True if not a covering index */
-    WhereTerm *pTerm;             /* A single term of the WHERE clause */
-#ifdef SQLITE_ENABLE_STAT3
-    WhereTerm *pFirstTerm = 0;    /* First term matching the index */
-#endif
-
-    WHERETRACE((
-      "   %s(%s):\n",
-      pSrc->pTab->zName, (pIdx ? pIdx->zName : "ipk")
-    ));
-    memset(&pc, 0, sizeof(pc));
-    pc.plan.nOBSat = nPriorSat;
-
-    /* Determine the values of pc.plan.nEq and nInMul */
-    for(pc.plan.nEq=0; pc.plan.nEq<pProbe->nColumn; pc.plan.nEq++){
-      int j = pProbe->aiColumn[pc.plan.nEq];
-      pTerm = findTerm(pWC, iCur, j, p->notReady, eqTermMask, pIdx);
-      if( pTerm==0 ) break;
-      pc.plan.wsFlags |= (WHERE_COLUMN_EQ|WHERE_ROWID_EQ);
-      testcase( pTerm->pWC!=pWC );
-      if( pTerm->eOperator & WO_IN ){
-        Expr *pExpr = pTerm->pExpr;
-        pc.plan.wsFlags |= WHERE_COLUMN_IN;
-        if( ExprHasProperty(pExpr, EP_xIsSelect) ){
-          /* "x IN (SELECT ...)":  Assume the SELECT returns 25 rows */
-          nInMul *= 25;
-          bInEst = 1;
-        }else if( ALWAYS(pExpr->x.pList && pExpr->x.pList->nExpr) ){
-          /* "x IN (value, value, ...)" */
-          nInMul *= pExpr->x.pList->nExpr;
-        }
-      }else if( pTerm->eOperator & WO_ISNULL ){
-        pc.plan.wsFlags |= WHERE_COLUMN_NULL;
-      }
-#ifdef SQLITE_ENABLE_STAT3
-      if( pc.plan.nEq==0 && pProbe->aSample ) pFirstTerm = pTerm;
-#endif
-      pc.used |= pTerm->prereqRight;
-    }
- 
-    /* If the index being considered is UNIQUE, and there is an equality 
-    ** constraint for all columns in the index, then this search will find
-    ** at most a single row. In this case set the WHERE_UNIQUE flag to 
-    ** indicate this to the caller.
-    **
-    ** Otherwise, if the search may find more than one row, test to see if
-    ** there is a range constraint on indexed column (pc.plan.nEq+1) that
-    ** can be optimized using the index. 
-    */
-    if( pc.plan.nEq==pProbe->nColumn && pProbe->onError!=OE_None ){
-      testcase( pc.plan.wsFlags & WHERE_COLUMN_IN );
-      testcase( pc.plan.wsFlags & WHERE_COLUMN_NULL );
-      if( (pc.plan.wsFlags & (WHERE_COLUMN_IN|WHERE_COLUMN_NULL))==0 ){
-        pc.plan.wsFlags |= WHERE_UNIQUE;
-        if( p->i==0 || (p->aLevel[p->i-1].plan.wsFlags & WHERE_ALL_UNIQUE)!=0 ){
-          pc.plan.wsFlags |= WHERE_ALL_UNIQUE;
-        }
-      }
-    }else if( pProbe->bUnordered==0 ){
-      int j;
-      j = (pc.plan.nEq==pProbe->nColumn ? -1 : pProbe->aiColumn[pc.plan.nEq]);
-      if( findTerm(pWC, iCur, j, p->notReady, WO_LT|WO_LE|WO_GT|WO_GE, pIdx) ){
-        WhereTerm *pTop, *pBtm;
-        pTop = findTerm(pWC, iCur, j, p->notReady, WO_LT|WO_LE, pIdx);
-        pBtm = findTerm(pWC, iCur, j, p->notReady, WO_GT|WO_GE, pIdx);
-        whereRangeScanEst(pParse, pProbe, pc.plan.nEq, pBtm, pTop, &rangeDiv);
-        if( pTop ){
-          nBound = 1;
-          pc.plan.wsFlags |= WHERE_TOP_LIMIT;
-          pc.used |= pTop->prereqRight;
-          testcase( pTop->pWC!=pWC );
-        }
-        if( pBtm ){
-          nBound++;
-          pc.plan.wsFlags |= WHERE_BTM_LIMIT;
-          pc.used |= pBtm->prereqRight;
-          testcase( pBtm->pWC!=pWC );
-        }
-        pc.plan.wsFlags |= (WHERE_COLUMN_RANGE|WHERE_ROWID_RANGE);
-      }
-    }
-
-    /* If there is an ORDER BY clause and the index being considered will
-    ** naturally scan rows in the required order, set the appropriate flags
-    ** in pc.plan.wsFlags. Otherwise, if there is an ORDER BY clause but
-    ** the index will scan rows in a different order, set the bSort
-    ** variable.  */
-    if( bSort && (pSrc->jointype & JT_LEFT)==0 ){
-      int bRev = 2;
-      int bObUnique = 0;
-      WHERETRACE(("      --> before isSortIndex: nPriorSat=%d\n",nPriorSat));
-      pc.plan.nOBSat = isSortingIndex(p, pProbe, iCur, &bRev, &bObUnique);
-      WHERETRACE(("      --> after  isSortIndex: bRev=%d bObU=%d nOBSat=%d\n",
-                  bRev, bObUnique, pc.plan.nOBSat));
-      if( nPriorSat<pc.plan.nOBSat || (pc.plan.wsFlags & WHERE_ALL_UNIQUE)!=0 ){
-        pc.plan.wsFlags |= WHERE_ORDERED;
-        if( bObUnique ) pc.plan.wsFlags |= WHERE_OB_UNIQUE;
-      }
-      if( nOrderBy==pc.plan.nOBSat ){
-        bSort = 0;
-        pc.plan.wsFlags |= WHERE_ROWID_RANGE|WHERE_COLUMN_RANGE;
-      }
-      if( bRev & 1 ) pc.plan.wsFlags |= WHERE_REVERSE;
-    }
-
-    /* If there is a DISTINCT qualifier and this index will scan rows in
-    ** order of the DISTINCT expressions, clear bDist and set the appropriate
-    ** flags in pc.plan.wsFlags. */
-    if( bDist
-     && isDistinctIndex(pParse, pWC, pProbe, iCur, p->pDistinct, pc.plan.nEq)
-     && (pc.plan.wsFlags & WHERE_COLUMN_IN)==0
-    ){
-      bDist = 0;
-      pc.plan.wsFlags |= WHERE_ROWID_RANGE|WHERE_COLUMN_RANGE|WHERE_DISTINCT;
-    }
-
-    /* If currently calculating the cost of using an index (not the IPK
-    ** index), determine if all required column data may be obtained without 
-    ** using the main table (i.e. if the index is a covering
-    ** index for this query). If it is, set the WHERE_IDX_ONLY flag in
-    ** pc.plan.wsFlags. Otherwise, set the bLookup variable to true.  */
-    if( pIdx ){
-      Bitmask m = pSrc->colUsed;
-      int j;
-      for(j=0; j<pIdx->nColumn; j++){
-        int x = pIdx->aiColumn[j];
-        if( x<BMS-1 ){
-          m &= ~(((Bitmask)1)<<x);
-        }
-      }
-      if( m==0 ){
-        pc.plan.wsFlags |= WHERE_IDX_ONLY;
-      }else{
-        bLookup = 1;
-      }
-    }
-
-    /*
-    ** Estimate the number of rows of output.  For an "x IN (SELECT...)"
-    ** constraint, do not let the estimate exceed half the rows in the table.
-    */
-    pc.plan.nRow = (double)(aiRowEst[pc.plan.nEq] * nInMul);
-    if( bInEst && pc.plan.nRow*2>aiRowEst[0] ){
-      pc.plan.nRow = aiRowEst[0]/2;
-      nInMul = (int)(pc.plan.nRow / aiRowEst[pc.plan.nEq]);
-    }
-
-#ifdef SQLITE_ENABLE_STAT3
-    /* If the constraint is of the form x=VALUE or x IN (E1,E2,...)
-    ** and we do not think that values of x are unique and if histogram
-    ** data is available for column x, then it might be possible
-    ** to get a better estimate on the number of rows based on
-    ** VALUE and how common that value is according to the histogram.
-    */
-    if( pc.plan.nRow>(double)1 && pc.plan.nEq==1
-     && pFirstTerm!=0 && aiRowEst[1]>1 ){
-      assert( (pFirstTerm->eOperator & (WO_EQ|WO_ISNULL|WO_IN))!=0 );
-      if( pFirstTerm->eOperator & (WO_EQ|WO_ISNULL) ){
-        testcase( pFirstTerm->eOperator & WO_EQ );
-        testcase( pFirstTerm->eOperator & WO_EQUIV );
-        testcase( pFirstTerm->eOperator & WO_ISNULL );
-        whereEqualScanEst(pParse, pProbe, pFirstTerm->pExpr->pRight,
-                          &pc.plan.nRow);
-      }else if( bInEst==0 ){
-        assert( pFirstTerm->eOperator & WO_IN );
-        whereInScanEst(pParse, pProbe, pFirstTerm->pExpr->x.pList,
-                       &pc.plan.nRow);
-      }
-    }
-#endif /* SQLITE_ENABLE_STAT3 */
-
-    /* Adjust the number of output rows and downward to reflect rows
-    ** that are excluded by range constraints.
-    */
-    pc.plan.nRow = pc.plan.nRow/rangeDiv;
-    if( pc.plan.nRow<1 ) pc.plan.nRow = 1;
-
-    /* Experiments run on real SQLite databases show that the time needed
-    ** to do a binary search to locate a row in a table or index is roughly
-    ** log10(N) times the time to move from one row to the next row within
-    ** a table or index.  The actual times can vary, with the size of
-    ** records being an important factor.  Both moves and searches are
-    ** slower with larger records, presumably because fewer records fit
-    ** on one page and hence more pages have to be fetched.
-    **
-    ** The ANALYZE command and the sqlite_stat1 and sqlite_stat3 tables do
-    ** not give us data on the relative sizes of table and index records.
-    ** So this computation assumes table records are about twice as big
-    ** as index records
-    */
-    if( (pc.plan.wsFlags&~(WHERE_REVERSE|WHERE_ORDERED|WHERE_OB_UNIQUE))
-                                                              ==WHERE_IDX_ONLY
-     && (pWC->wctrlFlags & WHERE_ONEPASS_DESIRED)==0
-     && sqlite3GlobalConfig.bUseCis
-     && OptimizationEnabled(pParse->db, SQLITE_CoverIdxScan)
-    ){
-      /* This index is not useful for indexing, but it is a covering index.
-      ** A full-scan of the index might be a little faster than a full-scan
-      ** of the table, so give this case a cost slightly less than a table
-      ** scan. */
-      pc.rCost = aiRowEst[0]*3 + pProbe->nColumn;
-      pc.plan.wsFlags |= WHERE_COVER_SCAN|WHERE_COLUMN_RANGE;
-    }else if( (pc.plan.wsFlags & WHERE_NOT_FULLSCAN)==0 ){
-      /* The cost of a full table scan is a number of move operations equal
-      ** to the number of rows in the table.
-      **
-      ** We add an additional 4x penalty to full table scans.  This causes
-      ** the cost function to err on the side of choosing an index over
-      ** choosing a full scan.  This 4x full-scan penalty is an arguable
-      ** decision and one which we expect to revisit in the future.  But
-      ** it seems to be working well enough at the moment.
-      */
-      pc.rCost = aiRowEst[0]*4;
-      pc.plan.wsFlags &= ~WHERE_IDX_ONLY;
-      if( pIdx ){
-        pc.plan.wsFlags &= ~WHERE_ORDERED;
-        pc.plan.nOBSat = nPriorSat;
-      }
-    }else{
-      log10N = estLog(aiRowEst[0]);
-      pc.rCost = pc.plan.nRow;
-      if( pIdx ){
-        if( bLookup ){
-          /* For an index lookup followed by a table lookup:
-          **    nInMul index searches to find the start of each index range
-          **  + nRow steps through the index
-          **  + nRow table searches to lookup the table entry using the rowid
-          */
-          pc.rCost += (nInMul + pc.plan.nRow)*log10N;
-        }else{
-          /* For a covering index:
-          **     nInMul index searches to find the initial entry 
-          **   + nRow steps through the index
-          */
-          pc.rCost += nInMul*log10N;
-        }
-      }else{
-        /* For a rowid primary key lookup:
-        **    nInMult table searches to find the initial entry for each range
-        **  + nRow steps through the table
-        */
-        pc.rCost += nInMul*log10N;
-      }
-    }
-
-    /* Add in the estimated cost of sorting the result.  Actual experimental
-    ** measurements of sorting performance in SQLite show that sorting time
-    ** adds C*N*log10(N) to the cost, where N is the number of rows to be 
-    ** sorted and C is a factor between 1.95 and 4.3.  We will split the
-    ** difference and select C of 3.0.
-    */
-    if( bSort ){
-      double m = estLog(pc.plan.nRow*(nOrderBy - pc.plan.nOBSat)/nOrderBy);
-      m *= (double)(pc.plan.nOBSat ? 2 : 3);
-      pc.rCost += pc.plan.nRow*m;
-    }
-    if( bDist ){
-      pc.rCost += pc.plan.nRow*estLog(pc.plan.nRow)*3;
-    }
-
-    /**** Cost of using this index has now been computed ****/
-
-    /* If there are additional constraints on this table that cannot
-    ** be used with the current index, but which might lower the number
-    ** of output rows, adjust the nRow value accordingly.  This only 
-    ** matters if the current index is the least costly, so do not bother
-    ** with this step if we already know this index will not be chosen.
-    ** Also, never reduce the output row count below 2 using this step.
-    **
-    ** It is critical that the notValid mask be used here instead of
-    ** the notReady mask.  When computing an "optimal" index, the notReady
-    ** mask will only have one bit set - the bit for the current table.
-    ** The notValid mask, on the other hand, always has all bits set for
-    ** tables that are not in outer loops.  If notReady is used here instead
-    ** of notValid, then a optimal index that depends on inner joins loops
-    ** might be selected even when there exists an optimal index that has
-    ** no such dependency.
-    */
-    if( pc.plan.nRow>2 && pc.rCost<=p->cost.rCost ){
-      int k;                       /* Loop counter */
-      int nSkipEq = pc.plan.nEq;   /* Number of == constraints to skip */
-      int nSkipRange = nBound;     /* Number of < constraints to skip */
-      Bitmask thisTab;             /* Bitmap for pSrc */
-
-      thisTab = getMask(pWC->pMaskSet, iCur);
-      for(pTerm=pWC->a, k=pWC->nTerm; pc.plan.nRow>2 && k; k--, pTerm++){
-        if( pTerm->wtFlags & TERM_VIRTUAL ) continue;
-        if( (pTerm->prereqAll & p->notValid)!=thisTab ) continue;
-        if( pTerm->eOperator & (WO_EQ|WO_IN|WO_ISNULL) ){
-          if( nSkipEq ){
-            /* Ignore the first pc.plan.nEq equality matches since the index
-            ** has already accounted for these */
-            nSkipEq--;
-          }else{
-            /* Assume each additional equality match reduces the result
-            ** set size by a factor of 10 */
-            pc.plan.nRow /= 10;
-          }
-        }else if( pTerm->eOperator & (WO_LT|WO_LE|WO_GT|WO_GE) ){
-          if( nSkipRange ){
-            /* Ignore the first nSkipRange range constraints since the index
-            ** has already accounted for these */
-            nSkipRange--;
-          }else{
-            /* Assume each additional range constraint reduces the result
-            ** set size by a factor of 3.  Indexed range constraints reduce
-            ** the search space by a larger factor: 4.  We make indexed range
-            ** more selective intentionally because of the subjective 
-            ** observation that indexed range constraints really are more
-            ** selective in practice, on average. */
-            pc.plan.nRow /= 3;
-          }
-        }else if( (pTerm->eOperator & WO_NOOP)==0 ){
-          /* Any other expression lowers the output row count by half */
-          pc.plan.nRow /= 2;
-        }
-      }
-      if( pc.plan.nRow<2 ) pc.plan.nRow = 2;
-    }
-
-
-    WHERETRACE((
-      "      nEq=%d nInMul=%d rangeDiv=%d bSort=%d bLookup=%d wsFlags=0x%08x\n"
-      "      notReady=0x%llx log10N=%.1f nRow=%.1f cost=%.1f\n"
-      "      used=0x%llx nOBSat=%d\n",
-      pc.plan.nEq, nInMul, (int)rangeDiv, bSort, bLookup, pc.plan.wsFlags,
-      p->notReady, log10N, pc.plan.nRow, pc.rCost, pc.used,
-      pc.plan.nOBSat
-    ));
-
-    /* If this index is the best we have seen so far, then record this
-    ** index and its cost in the p->cost structure.
-    */
-    if( (!pIdx || pc.plan.wsFlags) && compareCost(&pc, &p->cost) ){
-      p->cost = pc;
-      p->cost.plan.wsFlags &= wsFlagMask;
-      p->cost.plan.u.pIdx = pIdx;
-    }
-
-    /* If there was an INDEXED BY clause, then only that one index is
-    ** considered. */
-    if( pSrc->pIndex ) break;
-
-    /* Reset masks for the next index in the loop */
-    wsFlagMask = ~(WHERE_ROWID_EQ|WHERE_ROWID_RANGE);
-    eqTermMask = idxEqTermMask;
-  }
-
-  /* If there is no ORDER BY clause and the SQLITE_ReverseOrder flag
-  ** is set, then reverse the order that the index will be scanned
-  ** in. This is used for application testing, to help find cases
-  ** where application behavior depends on the (undefined) order that
-  ** SQLite outputs rows in in the absence of an ORDER BY clause.  */
-  if( !p->pOrderBy && pParse->db->flags & SQLITE_ReverseOrder ){
-    p->cost.plan.wsFlags |= WHERE_REVERSE;
-  }
-
-  assert( p->pOrderBy || (p->cost.plan.wsFlags&WHERE_ORDERED)==0 );
-  assert( p->cost.plan.u.pIdx==0 || (p->cost.plan.wsFlags&WHERE_ROWID_EQ)==0 );
-  assert( pSrc->pIndex==0 
-       || p->cost.plan.u.pIdx==0 
-       || p->cost.plan.u.pIdx==pSrc->pIndex 
-  );
-
-  WHERETRACE(("   best index is %s cost=%.1f\n",
-         p->cost.plan.u.pIdx ? p->cost.plan.u.pIdx->zName : "ipk",
-         p->cost.rCost));
-  
-  bestOrClauseIndex(p);
-  bestAutomaticIndex(p);
-  p->cost.plan.wsFlags |= eqTermMask;
-}
-
-/*
-** Find the query plan for accessing table pSrc->pTab. Write the
-** best query plan and its cost into the WhereCost object supplied 
-** as the last parameter. This function may calculate the cost of
-** both real and virtual table scans.
-**
-** This function does not take ORDER BY or DISTINCT into account.  Nor
-** does it remember the virtual table query plan.  All it does is compute
-** the cost while determining if an OR optimization is applicable.  The
-** details will be reconsidered later if the optimization is found to be
-** applicable.
-*/
-static void bestIndex(WhereBestIdx *p){
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-  if( IsVirtual(p->pSrc->pTab) ){
-    sqlite3_index_info *pIdxInfo = 0;
-    p->ppIdxInfo = &pIdxInfo;
-    bestVirtualIndex(p);
-    assert( pIdxInfo!=0 || p->pParse->db->mallocFailed );
-    if( pIdxInfo && pIdxInfo->needToFreeIdxStr ){
-      sqlite3_free(pIdxInfo->idxStr);
-    }
-    sqlite3DbFree(p->pParse->db, pIdxInfo);
-  }else
-#endif
-  {
-    bestBtreeIndex(p);
-  }
-}
-
-/*
 ** Disable a term in the WHERE clause.  Except, do not disable the term
 ** if it controls a LEFT OUTER JOIN and it did not originate in the ON
 ** or USING clause of that join.
@@ -3731,9 +2814,6 @@ static void bestIndex(WhereBestIdx *p){
 ** in the ON clause.  The term is disabled in (3) because it is not part
 ** of a LEFT OUTER JOIN.  In (1), the term is not disabled.
 **
-** IMPLEMENTATION-OF: R-24597-58655 No tests are done for terms that are
-** completely satisfied by indices.
-**
 ** Disabling a term causes that term to not be tested in the inner loop
 ** of the join.  Disabling is an optimization.  When terms are satisfied
 ** by indices, we disable them to prevent redundant tests in the inner
@@ -3813,6 +2893,7 @@ static int codeEqualityTerm(
   WhereTerm *pTerm,   /* The term of the WHERE clause to be coded */
   WhereLevel *pLevel, /* The level of the FROM clause we are working on */
   int iEq,            /* Index of the equality term within this level */
+  int bRev,           /* True for reverse-order IN operations */
   int iTarget         /* Attempt to leave results in this register */
 ){
   Expr *pX = pTerm->pExpr;
@@ -3830,14 +2911,13 @@ static int codeEqualityTerm(
     int eType;
     int iTab;
     struct InLoop *pIn;
-    u8 bRev = (pLevel->plan.wsFlags & WHERE_REVERSE)!=0;
+    WhereLoop *pLoop = pLevel->pWLoop;
 
-    if( (pLevel->plan.wsFlags & WHERE_INDEXED)!=0 
-      && pLevel->plan.u.pIdx->aSortOrder[iEq]
+    if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0
+      && pLoop->u.btree.pIndex!=0
+      && pLoop->u.btree.pIndex->aSortOrder[iEq]
     ){
       testcase( iEq==0 );
-      testcase( iEq==pLevel->plan.u.pIdx->nColumn-1 );
-      testcase( iEq>0 && iEq+1<pLevel->plan.u.pIdx->nColumn );
       testcase( bRev );
       bRev = !bRev;
     }
@@ -3850,7 +2930,8 @@ static int codeEqualityTerm(
     }
     iTab = pX->iTable;
     sqlite3VdbeAddOp2(v, bRev ? OP_Last : OP_Rewind, iTab, 0);
-    assert( pLevel->plan.wsFlags & WHERE_IN_ABLE );
+    assert( (pLoop->wsFlags & WHERE_MULTI_OR)==0 );
+    pLoop->wsFlags |= WHERE_IN_ABLE;
     if( pLevel->u.in.nIn==0 ){
       pLevel->addrNxt = sqlite3VdbeMakeLabel(v);
     }
@@ -3920,29 +3001,31 @@ static int codeEqualityTerm(
 static int codeAllEqualityTerms(
   Parse *pParse,        /* Parsing context */
   WhereLevel *pLevel,   /* Which nested loop of the FROM we are coding */
-  WhereClause *pWC,     /* The WHERE clause */
-  Bitmask notReady,     /* Which parts of FROM have not yet been coded */
+  int bRev,             /* Reverse the order of IN operators */
   int nExtraReg,        /* Number of extra registers to allocate */
   char **pzAff          /* OUT: Set to point to affinity string */
 ){
-  int nEq = pLevel->plan.nEq;   /* The number of == or IN constraints to code */
+  int nEq;                      /* The number of == or IN constraints to code */
   Vdbe *v = pParse->pVdbe;      /* The vm under construction */
   Index *pIdx;                  /* The index being used for this loop */
-  int iCur = pLevel->iTabCur;   /* The cursor of the table */
   WhereTerm *pTerm;             /* A single constraint term */
+  WhereLoop *pLoop;             /* The WhereLoop object */
   int j;                        /* Loop counter */
   int regBase;                  /* Base register */
   int nReg;                     /* Number of registers to allocate */
   char *zAff;                   /* Affinity string to return */
 
   /* This module is only called on query plans that use an index. */
-  assert( pLevel->plan.wsFlags & WHERE_INDEXED );
-  pIdx = pLevel->plan.u.pIdx;
+  pLoop = pLevel->pWLoop;
+  assert( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0 );
+  nEq = pLoop->u.btree.nEq;
+  pIdx = pLoop->u.btree.pIndex;
+  assert( pIdx!=0 );
 
   /* Figure out how many memory cells we will need then allocate them.
   */
   regBase = pParse->nMem + 1;
-  nReg = pLevel->plan.nEq + nExtraReg;
+  nReg = pLoop->u.btree.nEq + nExtraReg;
   pParse->nMem += nReg;
 
   zAff = sqlite3DbStrDup(pParse->db, sqlite3IndexAffinityStr(v, pIdx));
@@ -3952,17 +3035,16 @@ static int codeAllEqualityTerms(
 
   /* Evaluate the equality constraints
   */
-  assert( pIdx->nColumn>=nEq );
+  assert( zAff==0 || strlen(zAff)>=nEq );
   for(j=0; j<nEq; j++){
     int r1;
-    int k = pIdx->aiColumn[j];
-    pTerm = findTerm(pWC, iCur, k, notReady, pLevel->plan.wsFlags, pIdx);
-    if( pTerm==0 ) break;
+    pTerm = pLoop->aLTerm[j];
+    assert( pTerm!=0 );
     /* The following true for indices with redundant columns. 
     ** Ex: CREATE INDEX i1 ON t1(a,b,a); SELECT * FROM t1 WHERE a=0 AND b=0; */
     testcase( (pTerm->wtFlags & TERM_CODED)!=0 );
-    testcase( pTerm->wtFlags & TERM_VIRTUAL ); /* EV: R-30575-11662 */
-    r1 = codeEqualityTerm(pParse, pTerm, pLevel, j, regBase+j);
+    testcase( pTerm->wtFlags & TERM_VIRTUAL );
+    r1 = codeEqualityTerm(pParse, pTerm, pLevel, j, bRev, regBase+j);
     if( r1!=regBase+j ){
       if( nReg==1 ){
         sqlite3ReleaseTempReg(pParse, regBase);
@@ -4030,31 +3112,31 @@ static void explainAppendTerm(
 ** It is the responsibility of the caller to free the buffer when it is
 ** no longer required.
 */
-static char *explainIndexRange(sqlite3 *db, WhereLevel *pLevel, Table *pTab){
-  WherePlan *pPlan = &pLevel->plan;
-  Index *pIndex = pPlan->u.pIdx;
-  int nEq = pPlan->nEq;
+static char *explainIndexRange(sqlite3 *db, WhereLoop *pLoop, Table *pTab){
+  Index *pIndex = pLoop->u.btree.pIndex;
+  int nEq = pLoop->u.btree.nEq;
   int i, j;
   Column *aCol = pTab->aCol;
   int *aiColumn = pIndex->aiColumn;
   StrAccum txt;
 
-  if( nEq==0 && (pPlan->wsFlags & (WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))==0 ){
+  if( nEq==0 && (pLoop->wsFlags & (WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))==0 ){
     return 0;
   }
   sqlite3StrAccumInit(&txt, 0, 0, SQLITE_MAX_LENGTH);
   txt.db = db;
   sqlite3StrAccumAppend(&txt, " (", 2);
   for(i=0; i<nEq; i++){
-    explainAppendTerm(&txt, i, aCol[aiColumn[i]].zName, "=");
+    char *z = (i==pIndex->nColumn ) ? "rowid" : aCol[aiColumn[i]].zName;
+    explainAppendTerm(&txt, i, z, "=");
   }
 
   j = i;
-  if( pPlan->wsFlags&WHERE_BTM_LIMIT ){
+  if( pLoop->wsFlags&WHERE_BTM_LIMIT ){
     char *z = (j==pIndex->nColumn ) ? "rowid" : aCol[aiColumn[j]].zName;
     explainAppendTerm(&txt, i++, z, ">");
   }
-  if( pPlan->wsFlags&WHERE_TOP_LIMIT ){
+  if( pLoop->wsFlags&WHERE_TOP_LIMIT ){
     char *z = (j==pIndex->nColumn ) ? "rowid" : aCol[aiColumn[j]].zName;
     explainAppendTerm(&txt, i, z, "<");
   }
@@ -4077,20 +3159,22 @@ static void explainOneScan(
   u16 wctrlFlags                  /* Flags passed to sqlite3WhereBegin() */
 ){
   if( pParse->explain==2 ){
-    u32 flags = pLevel->plan.wsFlags;
     struct SrcList_item *pItem = &pTabList->a[pLevel->iFrom];
     Vdbe *v = pParse->pVdbe;      /* VM being constructed */
     sqlite3 *db = pParse->db;     /* Database handle */
     char *zMsg;                   /* Text to add to EQP output */
-    sqlite3_int64 nRow;           /* Expected number of rows visited by scan */
     int iId = pParse->iSelectId;  /* Select id (left-most output column) */
     int isSearch;                 /* True for a SEARCH. False for SCAN. */
+    WhereLoop *pLoop;             /* The controlling WhereLoop object */
+    u32 flags;                    /* Flags that describe this loop */
 
+    pLoop = pLevel->pWLoop;
+    flags = pLoop->wsFlags;
     if( (flags&WHERE_MULTI_OR) || (wctrlFlags&WHERE_ONETABLE_ONLY) ) return;
 
-    isSearch = (pLevel->plan.nEq>0)
-             || (flags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0
-             || (wctrlFlags&(WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX));
+    isSearch = (flags&(WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0
+            || ((flags&WHERE_VIRTUALTABLE)==0 && (pLoop->u.btree.nEq>0))
+            || (wctrlFlags&(WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX));
 
     zMsg = sqlite3MPrintf(db, "%s", isSearch?"SEARCH":"SCAN");
     if( pItem->pSelect ){
@@ -4102,43 +3186,37 @@ static void explainOneScan(
     if( pItem->zAlias ){
       zMsg = sqlite3MAppendf(db, zMsg, "%s AS %s", zMsg, pItem->zAlias);
     }
-    if( (flags & WHERE_INDEXED)!=0 ){
-      char *zWhere = explainIndexRange(db, pLevel, pItem->pTab);
-      zMsg = sqlite3MAppendf(db, zMsg, "%s USING %s%sINDEX%s%s%s", zMsg, 
-          ((flags & WHERE_TEMP_INDEX)?"AUTOMATIC ":""),
-          ((flags & WHERE_IDX_ONLY)?"COVERING ":""),
-          ((flags & WHERE_TEMP_INDEX)?"":" "),
-          ((flags & WHERE_TEMP_INDEX)?"": pLevel->plan.u.pIdx->zName),
-          zWhere
-      );
+    if( (flags & (WHERE_IPK|WHERE_VIRTUALTABLE))==0
+     && ALWAYS(pLoop->u.btree.pIndex!=0)
+    ){
+      char *zWhere = explainIndexRange(db, pLoop, pItem->pTab);
+      zMsg = sqlite3MAppendf(db, zMsg,
+               ((flags & WHERE_AUTO_INDEX) ? 
+                   "%s USING AUTOMATIC %sINDEX%.0s%s" :
+                   "%s USING %sINDEX %s%s"), 
+               zMsg, ((flags & WHERE_IDX_ONLY) ? "COVERING " : ""),
+               pLoop->u.btree.pIndex->zName, zWhere);
       sqlite3DbFree(db, zWhere);
-    }else if( flags & (WHERE_ROWID_EQ|WHERE_ROWID_RANGE) ){
+    }else if( (flags & WHERE_IPK)!=0 && (flags & WHERE_CONSTRAINT)!=0 ){
       zMsg = sqlite3MAppendf(db, zMsg, "%s USING INTEGER PRIMARY KEY", zMsg);
 
-      if( flags&WHERE_ROWID_EQ ){
+      if( flags&(WHERE_COLUMN_EQ|WHERE_COLUMN_IN) ){
         zMsg = sqlite3MAppendf(db, zMsg, "%s (rowid=?)", zMsg);
       }else if( (flags&WHERE_BOTH_LIMIT)==WHERE_BOTH_LIMIT ){
         zMsg = sqlite3MAppendf(db, zMsg, "%s (rowid>? AND rowid<?)", zMsg);
       }else if( flags&WHERE_BTM_LIMIT ){
         zMsg = sqlite3MAppendf(db, zMsg, "%s (rowid>?)", zMsg);
-      }else if( flags&WHERE_TOP_LIMIT ){
+      }else if( ALWAYS(flags&WHERE_TOP_LIMIT) ){
         zMsg = sqlite3MAppendf(db, zMsg, "%s (rowid<?)", zMsg);
       }
     }
 #ifndef SQLITE_OMIT_VIRTUALTABLE
     else if( (flags & WHERE_VIRTUALTABLE)!=0 ){
-      sqlite3_index_info *pVtabIdx = pLevel->plan.u.pVtabIdx;
       zMsg = sqlite3MAppendf(db, zMsg, "%s VIRTUAL TABLE INDEX %d:%s", zMsg,
-                  pVtabIdx->idxNum, pVtabIdx->idxStr);
+                  pLoop->u.vtab.idxNum, pLoop->u.vtab.idxStr);
     }
 #endif
-    if( wctrlFlags&(WHERE_ORDERBY_MIN|WHERE_ORDERBY_MAX) ){
-      testcase( wctrlFlags & WHERE_ORDERBY_MIN );
-      nRow = 1;
-    }else{
-      nRow = (sqlite3_int64)pLevel->plan.nRow;
-    }
-    zMsg = sqlite3MAppendf(db, zMsg, "%s (~%lld rows)", zMsg, nRow);
+    zMsg = sqlite3MAppendf(db, zMsg, "%s", zMsg);
     sqlite3VdbeAddOp4(v, OP_Explain, iId, iLevel, iFrom, zMsg, P4_DYNAMIC);
   }
 }
@@ -4154,7 +3232,6 @@ static void explainOneScan(
 static Bitmask codeOneLoopStart(
   WhereInfo *pWInfo,   /* Complete information about the WHERE clause */
   int iLevel,          /* Which level of pWInfo->a[] should be coded */
-  u16 wctrlFlags,      /* One of the WHERE_* flags defined in sqliteInt.h */
   Bitmask notReady     /* Which tables are currently available */
 ){
   int j, k;            /* Loop counters */
@@ -4163,9 +3240,11 @@ static Bitmask codeOneLoopStart(
   int omitTable;       /* True if we use the index only */
   int bRev;            /* True if we need to scan in reverse order */
   WhereLevel *pLevel;  /* The where level to be coded */
+  WhereLoop *pLoop;    /* The WhereLoop object being coded */
   WhereClause *pWC;    /* Decomposition of the entire WHERE clause */
   WhereTerm *pTerm;               /* A WHERE clause term */
   Parse *pParse;                  /* Parsing context */
+  sqlite3 *db;                    /* Database connection */
   Vdbe *v;                        /* The prepared stmt under constructions */
   struct SrcList_item *pTabItem;  /* FROM clause term being coded */
   int addrBrk;                    /* Jump here to break out of the loop */
@@ -4176,13 +3255,15 @@ static Bitmask codeOneLoopStart(
 
   pParse = pWInfo->pParse;
   v = pParse->pVdbe;
-  pWC = pWInfo->pWC;
+  pWC = &pWInfo->sWC;
+  db = pParse->db;
   pLevel = &pWInfo->a[iLevel];
+  pLoop = pLevel->pWLoop;
   pTabItem = &pWInfo->pTabList->a[pLevel->iFrom];
   iCur = pTabItem->iCursor;
-  bRev = (pLevel->plan.wsFlags & WHERE_REVERSE)!=0;
-  omitTable = (pLevel->plan.wsFlags & WHERE_IDX_ONLY)!=0 
-           && (wctrlFlags & WHERE_FORCE_TABLE)==0;
+  bRev = (pWInfo->revMask>>iLevel)&1;
+  omitTable = (pLoop->wsFlags & WHERE_IDX_ONLY)!=0 
+           && (pWInfo->wctrlFlags & WHERE_FORCE_TABLE)==0;
   VdbeNoopComment((v, "Begin Join Loop %d", iLevel));
 
   /* Create labels for the "break" and "continue" instructions
@@ -4219,47 +3300,37 @@ static Bitmask codeOneLoopStart(
   }else
 
 #ifndef SQLITE_OMIT_VIRTUALTABLE
-  if(  (pLevel->plan.wsFlags & WHERE_VIRTUALTABLE)!=0 ){
-    /* Case 0:  The table is a virtual-table.  Use the VFilter and VNext
+  if(  (pLoop->wsFlags & WHERE_VIRTUALTABLE)!=0 ){
+    /* Case 1:  The table is a virtual-table.  Use the VFilter and VNext
     **          to access the data.
     */
     int iReg;   /* P3 Value for OP_VFilter */
     int addrNotFound;
-    sqlite3_index_info *pVtabIdx = pLevel->plan.u.pVtabIdx;
-    int nConstraint = pVtabIdx->nConstraint;
-    struct sqlite3_index_constraint_usage *aUsage =
-                                                pVtabIdx->aConstraintUsage;
-    const struct sqlite3_index_constraint *aConstraint =
-                                                pVtabIdx->aConstraint;
+    int nConstraint = pLoop->nLTerm;
 
     sqlite3ExprCachePush(pParse);
     iReg = sqlite3GetTempRange(pParse, nConstraint+2);
     addrNotFound = pLevel->addrBrk;
-    for(j=1; j<=nConstraint; j++){
-      for(k=0; k<nConstraint; k++){
-        if( aUsage[k].argvIndex==j ){
-          int iTarget = iReg+j+1;
-          pTerm = &pWC->a[aConstraint[k].iTermOffset];
-          if( pTerm->eOperator & WO_IN ){
-            codeEqualityTerm(pParse, pTerm, pLevel, k, iTarget);
-            addrNotFound = pLevel->addrNxt;
-          }else{
-            sqlite3ExprCode(pParse, pTerm->pExpr->pRight, iTarget);
-          }
-          break;
-        }
+    for(j=0; j<nConstraint; j++){
+      int iTarget = iReg+j+2;
+      pTerm = pLoop->aLTerm[j];
+      if( pTerm==0 ) continue;
+      if( pTerm->eOperator & WO_IN ){
+        codeEqualityTerm(pParse, pTerm, pLevel, j, bRev, iTarget);
+        addrNotFound = pLevel->addrNxt;
+      }else{
+        sqlite3ExprCode(pParse, pTerm->pExpr->pRight, iTarget);
       }
-      if( k==nConstraint ) break;
     }
-    sqlite3VdbeAddOp2(v, OP_Integer, pVtabIdx->idxNum, iReg);
-    sqlite3VdbeAddOp2(v, OP_Integer, j-1, iReg+1);
-    sqlite3VdbeAddOp4(v, OP_VFilter, iCur, addrNotFound, iReg, pVtabIdx->idxStr,
-                      pVtabIdx->needToFreeIdxStr ? P4_MPRINTF : P4_STATIC);
-    pVtabIdx->needToFreeIdxStr = 0;
-    for(j=0; j<nConstraint; j++){
-      if( aUsage[j].omit ){
-        int iTerm = aConstraint[j].iTermOffset;
-        disableTerm(pLevel, &pWC->a[iTerm]);
+    sqlite3VdbeAddOp2(v, OP_Integer, pLoop->u.vtab.idxNum, iReg);
+    sqlite3VdbeAddOp2(v, OP_Integer, nConstraint, iReg+1);
+    sqlite3VdbeAddOp4(v, OP_VFilter, iCur, addrNotFound, iReg,
+                      pLoop->u.vtab.idxStr,
+                      pLoop->u.vtab.needFree ? P4_MPRINTF : P4_STATIC);
+    pLoop->u.vtab.needFree = 0;
+    for(j=0; j<nConstraint && j<16; j++){
+      if( (pLoop->u.vtab.omitMask>>j)&1 ){
+        disableTerm(pLevel, pLoop->aLTerm[j]);
       }
     }
     pLevel->op = OP_VNext;
@@ -4270,19 +3341,22 @@ static Bitmask codeOneLoopStart(
   }else
 #endif /* SQLITE_OMIT_VIRTUALTABLE */
 
-  if( pLevel->plan.wsFlags & WHERE_ROWID_EQ ){
-    /* Case 1:  We can directly reference a single row using an
+  if( (pLoop->wsFlags & WHERE_IPK)!=0
+   && (pLoop->wsFlags & (WHERE_COLUMN_IN|WHERE_COLUMN_EQ))!=0
+  ){
+    /* Case 2:  We can directly reference a single row using an
     **          equality comparison against the ROWID field.  Or
     **          we reference multiple rows using a "rowid IN (...)"
     **          construct.
     */
+    assert( pLoop->u.btree.nEq==1 );
     iReleaseReg = sqlite3GetTempReg(pParse);
-    pTerm = findTerm(pWC, iCur, -1, notReady, WO_EQ|WO_IN, 0);
+    pTerm = pLoop->aLTerm[0];
     assert( pTerm!=0 );
     assert( pTerm->pExpr!=0 );
     assert( omitTable==0 );
-    testcase( pTerm->wtFlags & TERM_VIRTUAL ); /* EV: R-30575-11662 */
-    iRowidReg = codeEqualityTerm(pParse, pTerm, pLevel, 0, iReleaseReg);
+    testcase( pTerm->wtFlags & TERM_VIRTUAL );
+    iRowidReg = codeEqualityTerm(pParse, pTerm, pLevel, 0, bRev, iReleaseReg);
     addrNxt = pLevel->addrNxt;
     sqlite3VdbeAddOp2(v, OP_MustBeInt, iRowidReg, addrNxt);
     sqlite3VdbeAddOp3(v, OP_NotExists, iCur, addrNxt, iRowidReg);
@@ -4290,8 +3364,10 @@ static Bitmask codeOneLoopStart(
     sqlite3ExprCacheStore(pParse, iCur, -1, iRowidReg);
     VdbeComment((v, "pk"));
     pLevel->op = OP_Noop;
-  }else if( pLevel->plan.wsFlags & WHERE_ROWID_RANGE ){
-    /* Case 2:  We have an inequality comparison against the ROWID field.
+  }else if( (pLoop->wsFlags & WHERE_IPK)!=0
+         && (pLoop->wsFlags & WHERE_COLUMN_RANGE)!=0
+  ){
+    /* Case 3:  We have an inequality comparison against the ROWID field.
     */
     int testOp = OP_Noop;
     int start;
@@ -4299,8 +3375,11 @@ static Bitmask codeOneLoopStart(
     WhereTerm *pStart, *pEnd;
 
     assert( omitTable==0 );
-    pStart = findTerm(pWC, iCur, -1, notReady, WO_GT|WO_GE, 0);
-    pEnd = findTerm(pWC, iCur, -1, notReady, WO_LT|WO_LE, 0);
+    j = 0;
+    pStart = pEnd = 0;
+    if( pLoop->wsFlags & WHERE_BTM_LIMIT ) pStart = pLoop->aLTerm[j++];
+    if( pLoop->wsFlags & WHERE_TOP_LIMIT ) pEnd = pLoop->aLTerm[j++];
+    assert( pStart!=0 || pEnd!=0 );
     if( bRev ){
       pTerm = pStart;
       pStart = pEnd;
@@ -4323,10 +3402,11 @@ static Bitmask codeOneLoopStart(
       assert( TK_LT==TK_GT+2 );      /*  ... of the TK_xx values... */
       assert( TK_GE==TK_GT+3 );      /*  ... is correcct. */
 
-      testcase( pStart->wtFlags & TERM_VIRTUAL ); /* EV: R-30575-11662 */
+      assert( (pStart->wtFlags & TERM_VNULL)==0 );
+      testcase( pStart->wtFlags & TERM_VIRTUAL );
       pX = pStart->pExpr;
       assert( pX!=0 );
-      assert( pStart->leftCursor==iCur );
+      testcase( pStart->leftCursor!=iCur ); /* transitive constraints */
       r1 = sqlite3ExprCodeTemp(pParse, pX->pRight, &rTemp);
       sqlite3VdbeAddOp3(v, aMoveOp[pX->op-TK_GT], iCur, addrBrk, r1);
       VdbeComment((v, "pk"));
@@ -4340,8 +3420,9 @@ static Bitmask codeOneLoopStart(
       Expr *pX;
       pX = pEnd->pExpr;
       assert( pX!=0 );
-      assert( pEnd->leftCursor==iCur );
-      testcase( pEnd->wtFlags & TERM_VIRTUAL ); /* EV: R-30575-11662 */
+      assert( (pEnd->wtFlags & TERM_VNULL)==0 );
+      testcase( pEnd->leftCursor!=iCur ); /* Transitive constraints */
+      testcase( pEnd->wtFlags & TERM_VIRTUAL );
       memEndValue = ++pParse->nMem;
       sqlite3ExprCode(pParse, pX->pRight, memEndValue);
       if( pX->op==TK_LT || pX->op==TK_GT ){
@@ -4355,11 +3436,7 @@ static Bitmask codeOneLoopStart(
     pLevel->op = bRev ? OP_Prev : OP_Next;
     pLevel->p1 = iCur;
     pLevel->p2 = start;
-    if( pStart==0 && pEnd==0 ){
-      pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
-    }else{
-      assert( pLevel->p5==0 );
-    }
+    assert( pLevel->p5==0 );
     if( testOp!=OP_Noop ){
       iRowidReg = iReleaseReg = sqlite3GetTempReg(pParse);
       sqlite3VdbeAddOp2(v, OP_Rowid, iCur, iRowidReg);
@@ -4367,8 +3444,8 @@ static Bitmask codeOneLoopStart(
       sqlite3VdbeAddOp3(v, testOp, memEndValue, addrBrk, iRowidReg);
       sqlite3VdbeChangeP5(v, SQLITE_AFF_NUMERIC | SQLITE_JUMPIFNULL);
     }
-  }else if( pLevel->plan.wsFlags & (WHERE_COLUMN_RANGE|WHERE_COLUMN_EQ) ){
-    /* Case 3: A scan using an index.
+  }else if( pLoop->wsFlags & WHERE_INDEXED ){
+    /* Case 4: A scan using an index.
     **
     **         The WHERE clause may contain zero or more equality 
     **         terms ("==" or "IN" operators) that refer to the N
@@ -4414,8 +3491,8 @@ static Bitmask codeOneLoopStart(
       OP_IdxGE,            /* 1: (end_constraints && !bRev) */
       OP_IdxLT             /* 2: (end_constraints && bRev) */
     };
-    int nEq = pLevel->plan.nEq;  /* Number of == or IN terms */
-    int isMinQuery = 0;          /* If this is an optimized SELECT min(x).. */
+    int nEq = pLoop->u.btree.nEq;  /* Number of == or IN terms */
+    int isMinQuery = 0;            /* If this is an optimized SELECT min(x).. */
     int regBase;                 /* Base register holding constraint values */
     int r1;                      /* Temp register */
     WhereTerm *pRangeStart = 0;  /* Inequality constraint at range start */
@@ -4431,9 +3508,8 @@ static Bitmask codeOneLoopStart(
     char *zStartAff;             /* Affinity for start of range constraint */
     char *zEndAff;               /* Affinity for end of range constraint */
 
-    pIdx = pLevel->plan.u.pIdx;
+    pIdx = pLoop->u.btree.pIndex;
     iIdxCur = pLevel->iIdxCur;
-    k = (nEq==pIdx->nColumn ? -1 : pIdx->aiColumn[nEq]);
 
     /* If this loop satisfies a sort order (pOrderBy) request that 
     ** was passed to this function to implement a "SELECT min(x) ..." 
@@ -4443,8 +3519,8 @@ static Bitmask codeOneLoopStart(
     ** the first one after the nEq equality constraints in the index,
     ** this requires some special handling.
     */
-    if( (wctrlFlags&WHERE_ORDERBY_MIN)!=0
-     && (pLevel->plan.wsFlags&WHERE_ORDERED)
+    if( (pWInfo->wctrlFlags&WHERE_ORDERBY_MIN)!=0
+     && (pWInfo->bOBSat!=0)
      && (pIdx->nColumn>nEq)
     ){
       /* assert( pOrderBy->nExpr==1 ); */
@@ -4456,12 +3532,13 @@ static Bitmask codeOneLoopStart(
     /* Find any inequality constraint terms for the start and end 
     ** of the range. 
     */
-    if( pLevel->plan.wsFlags & WHERE_TOP_LIMIT ){
-      pRangeEnd = findTerm(pWC, iCur, k, notReady, (WO_LT|WO_LE), pIdx);
+    j = nEq;
+    if( pLoop->wsFlags & WHERE_BTM_LIMIT ){
+      pRangeStart = pLoop->aLTerm[j++];
       nExtraReg = 1;
     }
-    if( pLevel->plan.wsFlags & WHERE_BTM_LIMIT ){
-      pRangeStart = findTerm(pWC, iCur, k, notReady, (WO_GT|WO_GE), pIdx);
+    if( pLoop->wsFlags & WHERE_TOP_LIMIT ){
+      pRangeEnd = pLoop->aLTerm[j++];
       nExtraReg = 1;
     }
 
@@ -4469,10 +3546,8 @@ static Bitmask codeOneLoopStart(
     ** and store the values of those terms in an array of registers
     ** starting at regBase.
     */
-    regBase = codeAllEqualityTerms(
-        pParse, pLevel, pWC, notReady, nExtraReg, &zStartAff
-    );
-    zEndAff = sqlite3DbStrDup(pParse->db, zStartAff);
+    regBase = codeAllEqualityTerms(pParse,pLevel,bRev,nExtraReg,&zStartAff);
+    zEndAff = sqlite3DbStrDup(db, zStartAff);
     addrNxt = pLevel->addrNxt;
 
     /* If we are doing a reverse order scan on an ascending index, or
@@ -4485,10 +3560,10 @@ static Bitmask codeOneLoopStart(
       SWAP(WhereTerm *, pRangeEnd, pRangeStart);
     }
 
-    testcase( pRangeStart && pRangeStart->eOperator & WO_LE );
-    testcase( pRangeStart && pRangeStart->eOperator & WO_GE );
-    testcase( pRangeEnd && pRangeEnd->eOperator & WO_LE );
-    testcase( pRangeEnd && pRangeEnd->eOperator & WO_GE );
+    testcase( pRangeStart && (pRangeStart->eOperator & WO_LE)!=0 );
+    testcase( pRangeStart && (pRangeStart->eOperator & WO_GE)!=0 );
+    testcase( pRangeEnd && (pRangeEnd->eOperator & WO_LE)!=0 );
+    testcase( pRangeEnd && (pRangeEnd->eOperator & WO_GE)!=0 );
     startEq = !pRangeStart || pRangeStart->eOperator & (WO_LE|WO_GE);
     endEq =   !pRangeEnd || pRangeEnd->eOperator & (WO_LE|WO_GE);
     start_constraints = pRangeStart || nEq>0;
@@ -4513,7 +3588,7 @@ static Bitmask codeOneLoopStart(
         }
       }  
       nConstraint++;
-      testcase( pRangeStart->wtFlags & TERM_VIRTUAL ); /* EV: R-30575-11662 */
+      testcase( pRangeStart->wtFlags & TERM_VIRTUAL );
     }else if( isMinQuery ){
       sqlite3VdbeAddOp2(v, OP_Null, 0, regBase+nEq);
       nConstraint++;
@@ -4555,10 +3630,10 @@ static Bitmask codeOneLoopStart(
       }  
       codeApplyAffinity(pParse, regBase, nEq+1, zEndAff);
       nConstraint++;
-      testcase( pRangeEnd->wtFlags & TERM_VIRTUAL ); /* EV: R-30575-11662 */
+      testcase( pRangeEnd->wtFlags & TERM_VIRTUAL );
     }
-    sqlite3DbFree(pParse->db, zStartAff);
-    sqlite3DbFree(pParse->db, zEndAff);
+    sqlite3DbFree(db, zStartAff);
+    sqlite3DbFree(db, zEndAff);
 
     /* Top of the loop body */
     pLevel->p2 = sqlite3VdbeCurrentAddr(v);
@@ -4578,9 +3653,9 @@ static Bitmask codeOneLoopStart(
     ** If it is, jump to the next iteration of the loop.
     */
     r1 = sqlite3GetTempReg(pParse);
-    testcase( pLevel->plan.wsFlags & WHERE_BTM_LIMIT );
-    testcase( pLevel->plan.wsFlags & WHERE_TOP_LIMIT );
-    if( (pLevel->plan.wsFlags & (WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0 ){
+    testcase( pLoop->wsFlags & WHERE_BTM_LIMIT );
+    testcase( pLoop->wsFlags & WHERE_TOP_LIMIT );
+    if( (pLoop->wsFlags & (WHERE_BTM_LIMIT|WHERE_TOP_LIMIT))!=0 ){
       sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, nEq, r1);
       sqlite3VdbeAddOp2(v, OP_IsNull, r1, addrCont);
     }
@@ -4599,7 +3674,7 @@ static Bitmask codeOneLoopStart(
     /* Record the instruction used to terminate the loop. Disable 
     ** WHERE clause terms made redundant by the index range scan.
     */
-    if( pLevel->plan.wsFlags & WHERE_UNIQUE ){
+    if( pLoop->wsFlags & WHERE_ONEROW ){
       pLevel->op = OP_Noop;
     }else if( bRev ){
       pLevel->op = OP_Prev;
@@ -4607,7 +3682,7 @@ static Bitmask codeOneLoopStart(
       pLevel->op = OP_Next;
     }
     pLevel->p1 = iIdxCur;
-    if( pLevel->plan.wsFlags & WHERE_COVER_SCAN ){
+    if( (pLoop->wsFlags & WHERE_CONSTRAINT)==0 ){
       pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
     }else{
       assert( pLevel->p5==0 );
@@ -4615,8 +3690,8 @@ static Bitmask codeOneLoopStart(
   }else
 
 #ifndef SQLITE_OMIT_OR_OPTIMIZATION
-  if( pLevel->plan.wsFlags & WHERE_MULTI_OR ){
-    /* Case 4:  Two or more separately indexed terms connected by OR
+  if( pLoop->wsFlags & WHERE_MULTI_OR ){
+    /* Case 5:  Two or more separately indexed terms connected by OR
     **
     ** Example:
     **
@@ -4669,7 +3744,7 @@ static Bitmask codeOneLoopStart(
     int ii;                            /* Loop counter */
     Expr *pAndExpr = 0;                /* An ".. AND (...)" expression */
    
-    pTerm = pLevel->plan.u.pTerm;
+    pTerm = pLoop->aLTerm[0];
     assert( pTerm!=0 );
     assert( pTerm->eOperator & WO_OR );
     assert( (pTerm->wtFlags & TERM_ORINFO)!=0 );
@@ -4685,10 +3760,10 @@ static Bitmask codeOneLoopStart(
       int nNotReady;                 /* The number of notReady tables */
       struct SrcList_item *origSrc;     /* Original list of tables */
       nNotReady = pWInfo->nLevel - iLevel - 1;
-      pOrTab = sqlite3StackAllocRaw(pParse->db,
+      pOrTab = sqlite3StackAllocRaw(db,
                             sizeof(*pOrTab)+ nNotReady*sizeof(pOrTab->a[0]));
       if( pOrTab==0 ) return notReady;
-      pOrTab->nAlloc = (i16)(nNotReady + 1);
+      pOrTab->nAlloc = (u8)(nNotReady + 1);
       pOrTab->nSrc = pOrTab->nAlloc;
       memcpy(pOrTab->a, pTabItem, sizeof(*pTabItem));
       origSrc = pWInfo->pTabList->a;
@@ -4710,7 +3785,7 @@ static Bitmask codeOneLoopStart(
     ** fall through to the next instruction, just as an OP_Next does if
     ** called on an uninitialized cursor.
     */
-    if( (wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
+    if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
       regRowset = ++pParse->nMem;
       regRowid = ++pParse->nMem;
       sqlite3VdbeAddOp2(v, OP_Null, 0, regRowset);
@@ -4735,11 +3810,12 @@ static Bitmask codeOneLoopStart(
       int iTerm;
       for(iTerm=0; iTerm<pWC->nTerm; iTerm++){
         Expr *pExpr = pWC->a[iTerm].pExpr;
+        if( &pWC->a[iTerm] == pTerm ) continue;
         if( ExprHasProperty(pExpr, EP_FromJoin) ) continue;
-        if( pWC->a[iTerm].wtFlags & (TERM_VIRTUAL|TERM_ORINFO) ) continue;
+        if( pWC->a[iTerm].wtFlags & (TERM_ORINFO) ) continue;
         if( (pWC->a[iTerm].eOperator & WO_ALL)==0 ) continue;
-        pExpr = sqlite3ExprDup(pParse->db, pExpr, 0);
-        pAndExpr = sqlite3ExprAnd(pParse->db, pAndExpr, pExpr);
+        pExpr = sqlite3ExprDup(db, pExpr, 0);
+        pAndExpr = sqlite3ExprAnd(db, pAndExpr, pExpr);
       }
       if( pAndExpr ){
         pAndExpr = sqlite3PExpr(pParse, TK_AND, 0, pAndExpr, 0);
@@ -4759,13 +3835,13 @@ static Bitmask codeOneLoopStart(
         pSubWInfo = sqlite3WhereBegin(pParse, pOrTab, pOrExpr, 0, 0,
                         WHERE_OMIT_OPEN_CLOSE | WHERE_AND_ONLY |
                         WHERE_FORCE_TABLE | WHERE_ONETABLE_ONLY, iCovCur);
-        assert( pSubWInfo || pParse->nErr || pParse->db->mallocFailed );
+        assert( pSubWInfo || pParse->nErr || db->mallocFailed );
         if( pSubWInfo ){
-          WhereLevel *pLvl;
+          WhereLoop *pSubLoop;
           explainOneScan(
               pParse, pOrTab, &pSubWInfo->a[0], iLevel, pLevel->iFrom, 0
           );
-          if( (wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
+          if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
             int iSet = ((ii==pOrWc->nTerm-1)?-1:ii);
             int r;
             r = sqlite3ExprCodeGetColumn(pParse, pTabItem->pTab, -1, iCur, 
@@ -4794,13 +3870,13 @@ static Bitmask codeOneLoopStart(
           ** pCov to NULL to indicate that no candidate covering index will 
           ** be available.
           */
-          pLvl = &pSubWInfo->a[0];
-          if( (pLvl->plan.wsFlags & WHERE_INDEXED)!=0
-           && (pLvl->plan.wsFlags & WHERE_TEMP_INDEX)==0
-           && (ii==0 || pLvl->plan.u.pIdx==pCov)
+          pSubLoop = pSubWInfo->a[0].pWLoop;
+          assert( (pSubLoop->wsFlags & WHERE_AUTO_INDEX)==0 );
+          if( (pSubLoop->wsFlags & WHERE_INDEXED)!=0
+           && (ii==0 || pSubLoop->u.btree.pIndex==pCov)
           ){
-            assert( pLvl->iIdxCur==iCovCur );
-            pCov = pLvl->plan.u.pIdx;
+            assert( pSubWInfo->a[0].iIdxCur==iCovCur );
+            pCov = pSubLoop->u.btree.pIndex;
           }else{
             pCov = 0;
           }
@@ -4814,42 +3890,37 @@ static Bitmask codeOneLoopStart(
     if( pCov ) pLevel->iIdxCur = iCovCur;
     if( pAndExpr ){
       pAndExpr->pLeft = 0;
-      sqlite3ExprDelete(pParse->db, pAndExpr);
+      sqlite3ExprDelete(db, pAndExpr);
     }
     sqlite3VdbeChangeP1(v, iRetInit, sqlite3VdbeCurrentAddr(v));
     sqlite3VdbeAddOp2(v, OP_Goto, 0, pLevel->addrBrk);
     sqlite3VdbeResolveLabel(v, iLoopBody);
 
-    if( pWInfo->nLevel>1 ) sqlite3StackFree(pParse->db, pOrTab);
+    if( pWInfo->nLevel>1 ) sqlite3StackFree(db, pOrTab);
     if( !untestedTerms ) disableTerm(pLevel, pTerm);
   }else
 #endif /* SQLITE_OMIT_OR_OPTIMIZATION */
 
   {
-    /* Case 5:  There is no usable index.  We must do a complete
+    /* Case 6:  There is no usable index.  We must do a complete
     **          scan of the entire table.
     */
     static const u8 aStep[] = { OP_Next, OP_Prev };
     static const u8 aStart[] = { OP_Rewind, OP_Last };
     assert( bRev==0 || bRev==1 );
-    assert( omitTable==0 );
     pLevel->op = aStep[bRev];
     pLevel->p1 = iCur;
     pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, aStart[bRev], iCur, addrBrk);
     pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
   }
-  newNotReady = notReady & ~getMask(pWC->pMaskSet, iCur);
+  newNotReady = notReady & ~getMask(&pWInfo->sMaskSet, iCur);
 
   /* Insert code to test every subexpression that can be completely
   ** computed using the current set of tables.
-  **
-  ** IMPLEMENTATION-OF: R-49525-50935 Terms that cannot be satisfied through
-  ** the use of indices become tests that are evaluated against each row of
-  ** the relevant input tables.
   */
   for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
     Expr *pE;
-    testcase( pTerm->wtFlags & TERM_VIRTUAL ); /* IMP: R-30575-11662 */
+    testcase( pTerm->wtFlags & TERM_VIRTUAL );
     testcase( pTerm->wtFlags & TERM_CODED );
     if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
     if( (pTerm->prereqAll & newNotReady)!=0 ){
@@ -4876,22 +3947,28 @@ static Bitmask codeOneLoopStart(
   ** the implied "t1.a=123" constraint.
   */
   for(pTerm=pWC->a, j=pWC->nTerm; j>0; j--, pTerm++){
-    Expr *pE;
+    Expr *pE, *pEAlt;
     WhereTerm *pAlt;
-    Expr sEq;
     if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
     if( pTerm->eOperator!=(WO_EQUIV|WO_EQ) ) continue;
     if( pTerm->leftCursor!=iCur ) continue;
+    if( pLevel->iLeftJoin ) continue;
     pE = pTerm->pExpr;
     assert( !ExprHasProperty(pE, EP_FromJoin) );
     assert( (pTerm->prereqRight & newNotReady)!=0 );
     pAlt = findTerm(pWC, iCur, pTerm->u.leftColumn, notReady, WO_EQ|WO_IN, 0);
     if( pAlt==0 ) continue;
     if( pAlt->wtFlags & (TERM_CODED) ) continue;
+    testcase( pAlt->eOperator & WO_EQ );
+    testcase( pAlt->eOperator & WO_IN );
     VdbeNoopComment((v, "begin transitive constraint"));
-    sEq = *pAlt->pExpr;
-    sEq.pLeft = pE->pLeft;
-    sqlite3ExprIfFalse(pParse, &sEq, addrCont, SQLITE_JUMPIFNULL);
+    pEAlt = sqlite3StackAllocRaw(db, sizeof(*pEAlt));
+    if( pEAlt ){
+      *pEAlt = *pAlt->pExpr;
+      pEAlt->pLeft = pE->pLeft;
+      sqlite3ExprIfFalse(pParse, pEAlt, addrCont, SQLITE_JUMPIFNULL);
+      sqlite3StackFree(db, pEAlt);
+    }
   }
 
   /* For a LEFT OUTER JOIN, generate code that will record the fact that
@@ -4903,7 +3980,7 @@ static Bitmask codeOneLoopStart(
     VdbeComment((v, "record LEFT JOIN hit"));
     sqlite3ExprCacheClear(pParse);
     for(pTerm=pWC->a, j=0; j<pWC->nTerm; j++, pTerm++){
-      testcase( pTerm->wtFlags & TERM_VIRTUAL );  /* IMP: R-30575-11662 */
+      testcase( pTerm->wtFlags & TERM_VIRTUAL );
       testcase( pTerm->wtFlags & TERM_CODED );
       if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
       if( (pTerm->prereqAll & newNotReady)!=0 ){
@@ -4920,47 +3997,1601 @@ static Bitmask codeOneLoopStart(
   return newNotReady;
 }
 
-#if defined(SQLITE_TEST)
+#ifdef WHERETRACE_ENABLED
+/*
+** Print a WhereLoop object for debugging purposes
+*/
+static void whereLoopPrint(WhereLoop *p, SrcList *pTabList){
+  int nb = 1+(pTabList->nSrc+7)/8;
+  struct SrcList_item *pItem = pTabList->a + p->iTab;
+  Table *pTab = pItem->pTab;
+  sqlite3DebugPrintf("%c%2d.%0*llx.%0*llx", p->cId,
+                     p->iTab, nb, p->maskSelf, nb, p->prereq);
+  sqlite3DebugPrintf(" %12s",
+                     pItem->zAlias ? pItem->zAlias : pTab->zName);
+  if( (p->wsFlags & WHERE_VIRTUALTABLE)==0 ){
+    if( p->u.btree.pIndex ){
+      const char *zName = p->u.btree.pIndex->zName;
+      if( zName==0 ) zName = "ipk";
+      if( strncmp(zName, "sqlite_autoindex_", 17)==0 ){
+        int i = sqlite3Strlen30(zName) - 1;
+        while( zName[i]!='_' ) i--;
+        zName += i;
+      }
+      sqlite3DebugPrintf(".%-16s %2d", zName, p->u.btree.nEq);
+    }else{
+      sqlite3DebugPrintf("%20s","");
+    }
+  }else{
+    char *z;
+    if( p->u.vtab.idxStr ){
+      z = sqlite3_mprintf("(%d,\"%s\",%x)",
+                p->u.vtab.idxNum, p->u.vtab.idxStr, p->u.vtab.omitMask);
+    }else{
+      z = sqlite3_mprintf("(%d,%x)", p->u.vtab.idxNum, p->u.vtab.omitMask);
+    }
+    sqlite3DebugPrintf(" %-19s", z);
+    sqlite3_free(z);
+  }
+  sqlite3DebugPrintf(" f %04x N %d", p->wsFlags, p->nLTerm);
+  sqlite3DebugPrintf(" cost %d,%d,%d\n", p->rSetup, p->rRun, p->nOut);
+}
+#endif
+
+/*
+** Convert bulk memory into a valid WhereLoop that can be passed
+** to whereLoopClear harmlessly.
+*/
+static void whereLoopInit(WhereLoop *p){
+  p->aLTerm = p->aLTermSpace;
+  p->nLTerm = 0;
+  p->nLSlot = ArraySize(p->aLTermSpace);
+  p->wsFlags = 0;
+}
+
+/*
+** Clear the WhereLoop.u union.  Leave WhereLoop.pLTerm intact.
+*/
+static void whereLoopClearUnion(sqlite3 *db, WhereLoop *p){
+  if( p->wsFlags & (WHERE_VIRTUALTABLE|WHERE_AUTO_INDEX) ){
+    if( (p->wsFlags & WHERE_VIRTUALTABLE)!=0 && p->u.vtab.needFree ){
+      sqlite3_free(p->u.vtab.idxStr);
+      p->u.vtab.needFree = 0;
+      p->u.vtab.idxStr = 0;
+    }else if( (p->wsFlags & WHERE_AUTO_INDEX)!=0 && p->u.btree.pIndex!=0 ){
+      sqlite3DbFree(db, p->u.btree.pIndex->zColAff);
+      sqlite3DbFree(db, p->u.btree.pIndex);
+      p->u.btree.pIndex = 0;
+    }
+  }
+}
+
 /*
-** The following variable holds a text description of query plan generated
-** by the most recent call to sqlite3WhereBegin().  Each call to WhereBegin
-** overwrites the previous.  This information is used for testing and
-** analysis only.
+** Deallocate internal memory used by a WhereLoop object
 */
-char sqlite3_query_plan[BMS*2*40];  /* Text of the join */
-static int nQPlan = 0;              /* Next free slow in _query_plan[] */
+static void whereLoopClear(sqlite3 *db, WhereLoop *p){
+  if( p->aLTerm!=p->aLTermSpace ) sqlite3DbFree(db, p->aLTerm);
+  whereLoopClearUnion(db, p);
+  whereLoopInit(p);
+}
 
-#endif /* SQLITE_TEST */
+/*
+** Increase the memory allocation for pLoop->aLTerm[] to be at least n.
+*/
+static int whereLoopResize(sqlite3 *db, WhereLoop *p, int n){
+  WhereTerm **paNew;
+  if( p->nLSlot>=n ) return SQLITE_OK;
+  n = (n+7)&~7;
+  paNew = sqlite3DbMallocRaw(db, sizeof(p->aLTerm[0])*n);
+  if( paNew==0 ) return SQLITE_NOMEM;
+  memcpy(paNew, p->aLTerm, sizeof(p->aLTerm[0])*p->nLSlot);
+  if( p->aLTerm!=p->aLTermSpace ) sqlite3DbFree(db, p->aLTerm);
+  p->aLTerm = paNew;
+  p->nLSlot = n;
+  return SQLITE_OK;
+}
 
+/*
+** Transfer content from the second pLoop into the first.
+*/
+static int whereLoopXfer(sqlite3 *db, WhereLoop *pTo, WhereLoop *pFrom){
+  if( whereLoopResize(db, pTo, pFrom->nLTerm) ) return SQLITE_NOMEM;
+  whereLoopClearUnion(db, pTo);
+  memcpy(pTo, pFrom, WHERE_LOOP_XFER_SZ);
+  memcpy(pTo->aLTerm, pFrom->aLTerm, pTo->nLTerm*sizeof(pTo->aLTerm[0]));
+  if( pFrom->wsFlags & WHERE_VIRTUALTABLE ){
+    pFrom->u.vtab.needFree = 0;
+  }else if( (pFrom->wsFlags & WHERE_AUTO_INDEX)!=0 ){
+    pFrom->u.btree.pIndex = 0;
+  }
+  return SQLITE_OK;
+}
+
+/*
+** Delete a WhereLoop object
+*/
+static void whereLoopDelete(sqlite3 *db, WhereLoop *p){
+  whereLoopClear(db, p);
+  sqlite3DbFree(db, p);
+}
 
 /*
 ** Free a WhereInfo structure
 */
 static void whereInfoFree(sqlite3 *db, WhereInfo *pWInfo){
   if( ALWAYS(pWInfo) ){
-    int i;
-    for(i=0; i<pWInfo->nLevel; i++){
-      sqlite3_index_info *pInfo = pWInfo->a[i].pIdxInfo;
-      if( pInfo ){
-        /* assert( pInfo->needToFreeIdxStr==0 || db->mallocFailed ); */
-        if( pInfo->needToFreeIdxStr ){
-          sqlite3_free(pInfo->idxStr);
+    whereClauseClear(&pWInfo->sWC);
+    while( pWInfo->pLoops ){
+      WhereLoop *p = pWInfo->pLoops;
+      pWInfo->pLoops = p->pNextLoop;
+      whereLoopDelete(db, p);
+    }
+    sqlite3DbFree(db, pWInfo);
+  }
+}
+
+/*
+** Insert or replace a WhereLoop entry using the template supplied.
+**
+** An existing WhereLoop entry might be overwritten if the new template
+** is better and has fewer dependencies.  Or the template will be ignored
+** and no insert will occur if an existing WhereLoop is faster and has
+** fewer dependencies than the template.  Otherwise a new WhereLoop is
+** added based on the template.
+**
+** If pBuilder->pOrSet is not NULL then we only care about only the
+** prerequisites and rRun and nOut costs of the N best loops.  That
+** information is gathered in the pBuilder->pOrSet object.  This special
+** processing mode is used only for OR clause processing.
+**
+** When accumulating multiple loops (when pBuilder->pOrSet is NULL) we
+** still might overwrite similar loops with the new template if the
+** template is better.  Loops may be overwritten if the following 
+** conditions are met:
+**
+**    (1)  They have the same iTab.
+**    (2)  They have the same iSortIdx.
+**    (3)  The template has same or fewer dependencies than the current loop
+**    (4)  The template has the same or lower cost than the current loop
+**    (5)  The template uses more terms of the same index but has no additional
+**         dependencies          
+*/
+static int whereLoopInsert(WhereLoopBuilder *pBuilder, WhereLoop *pTemplate){
+  WhereLoop **ppPrev, *p, *pNext = 0;
+  WhereInfo *pWInfo = pBuilder->pWInfo;
+  sqlite3 *db = pWInfo->pParse->db;
+
+  /* If pBuilder->pOrSet is defined, then only keep track of the costs
+  ** and prereqs.
+  */
+  if( pBuilder->pOrSet!=0 ){
+#if WHERETRACE_ENABLED
+    u16 n = pBuilder->pOrSet->n;
+    int x =
+#endif
+    whereOrInsert(pBuilder->pOrSet, pTemplate->prereq, pTemplate->rRun,
+                                    pTemplate->nOut);
+#if WHERETRACE_ENABLED
+    if( sqlite3WhereTrace & 0x8 ){
+      sqlite3DebugPrintf(x?"   or-%d:  ":"   or-X:  ", n);
+      whereLoopPrint(pTemplate, pWInfo->pTabList);
+    }
+#endif
+    return SQLITE_OK;
+  }
+
+  /* Search for an existing WhereLoop to overwrite, or which takes
+  ** priority over pTemplate.
+  */
+  for(ppPrev=&pWInfo->pLoops, p=*ppPrev; p; ppPrev=&p->pNextLoop, p=*ppPrev){
+    if( p->iTab!=pTemplate->iTab || p->iSortIdx!=pTemplate->iSortIdx ){
+      /* If either the iTab or iSortIdx values for two WhereLoop are different
+      ** then those WhereLoops need to be considered separately.  Neither is
+      ** a candidate to replace the other. */
+      continue;
+    }
+    /* In the current implementation, the rSetup value is either zero
+    ** or the cost of building an automatic index (NlogN) and the NlogN
+    ** is the same for compatible WhereLoops. */
+    assert( p->rSetup==0 || pTemplate->rSetup==0 
+                 || p->rSetup==pTemplate->rSetup );
+
+    /* whereLoopAddBtree() always generates and inserts the automatic index
+    ** case first.  Hence compatible candidate WhereLoops never have a larger
+    ** rSetup. Call this SETUP-INVARIANT */
+    assert( p->rSetup>=pTemplate->rSetup );
+
+    if( (p->prereq & pTemplate->prereq)==p->prereq
+     && p->rSetup<=pTemplate->rSetup
+     && p->rRun<=pTemplate->rRun
+    ){
+      /* This branch taken when p is equal or better than pTemplate in 
+      ** all of (1) dependences (2) setup-cost, and (3) run-cost. */
+      assert( p->rSetup==pTemplate->rSetup );
+      if( p->nLTerm<pTemplate->nLTerm
+       && (p->wsFlags & WHERE_INDEXED)!=0
+       && (pTemplate->wsFlags & WHERE_INDEXED)!=0
+       && p->u.btree.pIndex==pTemplate->u.btree.pIndex
+       && p->prereq==pTemplate->prereq
+      ){
+        /* Overwrite an existing WhereLoop with an similar one that uses
+        ** more terms of the index */
+        pNext = p->pNextLoop;
+        break;
+      }else{
+        /* pTemplate is not helpful.
+        ** Return without changing or adding anything */
+        goto whereLoopInsert_noop;
+      }
+    }
+    if( (p->prereq & pTemplate->prereq)==pTemplate->prereq
+     && p->rRun>=pTemplate->rRun
+     && ALWAYS(p->rSetup>=pTemplate->rSetup) /* See SETUP-INVARIANT above */
+    ){
+      /* Overwrite an existing WhereLoop with a better one: one that is
+      ** better at one of (1) dependences, (2) setup-cost, or (3) run-cost
+      ** and is no worse in any of those categories. */
+      pNext = p->pNextLoop;
+      break;
+    }
+  }
+
+  /* If we reach this point it means that either p[] should be overwritten
+  ** with pTemplate[] if p[] exists, or if p==NULL then allocate a new
+  ** WhereLoop and insert it.
+  */
+#if WHERETRACE_ENABLED
+  if( sqlite3WhereTrace & 0x8 ){
+    if( p!=0 ){
+      sqlite3DebugPrintf("ins-del:  ");
+      whereLoopPrint(p, pWInfo->pTabList);
+    }
+    sqlite3DebugPrintf("ins-new:  ");
+    whereLoopPrint(pTemplate, pWInfo->pTabList);
+  }
+#endif
+  if( p==0 ){
+    p = sqlite3DbMallocRaw(db, sizeof(WhereLoop));
+    if( p==0 ) return SQLITE_NOMEM;
+    whereLoopInit(p);
+  }
+  whereLoopXfer(db, p, pTemplate);
+  p->pNextLoop = pNext;
+  *ppPrev = p;
+  if( (p->wsFlags & WHERE_VIRTUALTABLE)==0 ){
+    Index *pIndex = p->u.btree.pIndex;
+    if( pIndex && pIndex->tnum==0 ){
+      p->u.btree.pIndex = 0;
+    }
+  }
+  return SQLITE_OK;
+
+  /* Jump here if the insert is a no-op */
+whereLoopInsert_noop:
+#if WHERETRACE_ENABLED
+  if( sqlite3WhereTrace & 0x8 ){
+    sqlite3DebugPrintf("ins-noop: ");
+    whereLoopPrint(pTemplate, pWInfo->pTabList);
+  }
+#endif
+  return SQLITE_OK;  
+}
+
+/*
+** We have so far matched pBuilder->pNew->u.btree.nEq terms of the index pIndex.
+** Try to match one more.
+**
+** If pProbe->tnum==0, that means pIndex is a fake index used for the
+** INTEGER PRIMARY KEY.
+*/
+static int whereLoopAddBtreeIndex(
+  WhereLoopBuilder *pBuilder,     /* The WhereLoop factory */
+  struct SrcList_item *pSrc,      /* FROM clause term being analyzed */
+  Index *pProbe,                  /* An index on pSrc */
+  WhereCost nInMul                /* log(Number of iterations due to IN) */
+){
+  WhereInfo *pWInfo = pBuilder->pWInfo;  /* WHERE analyse context */
+  Parse *pParse = pWInfo->pParse;        /* Parsing context */
+  sqlite3 *db = pParse->db;       /* Database connection malloc context */
+  WhereLoop *pNew;                /* Template WhereLoop under construction */
+  WhereTerm *pTerm;               /* A WhereTerm under consideration */
+  int opMask;                     /* Valid operators for constraints */
+  WhereScan scan;                 /* Iterator for WHERE terms */
+  Bitmask saved_prereq;           /* Original value of pNew->prereq */
+  u16 saved_nLTerm;               /* Original value of pNew->nLTerm */
+  int saved_nEq;                  /* Original value of pNew->u.btree.nEq */
+  u32 saved_wsFlags;              /* Original value of pNew->wsFlags */
+  WhereCost saved_nOut;           /* Original value of pNew->nOut */
+  int iCol;                       /* Index of the column in the table */
+  int rc = SQLITE_OK;             /* Return code */
+  WhereCost nRowEst;              /* Estimated index selectivity */
+  WhereCost rLogSize;             /* Logarithm of table size */
+  WhereTerm *pTop = 0, *pBtm = 0; /* Top and bottom range constraints */
+
+  pNew = pBuilder->pNew;
+  if( db->mallocFailed ) return SQLITE_NOMEM;
+
+  assert( (pNew->wsFlags & WHERE_VIRTUALTABLE)==0 );
+  assert( (pNew->wsFlags & WHERE_TOP_LIMIT)==0 );
+  if( pNew->wsFlags & WHERE_BTM_LIMIT ){
+    opMask = WO_LT|WO_LE;
+  }else if( pProbe->tnum<=0 || (pSrc->jointype & JT_LEFT)!=0 ){
+    opMask = WO_EQ|WO_IN|WO_GT|WO_GE|WO_LT|WO_LE;
+  }else{
+    opMask = WO_EQ|WO_IN|WO_ISNULL|WO_GT|WO_GE|WO_LT|WO_LE;
+  }
+  if( pProbe->bUnordered ) opMask &= ~(WO_GT|WO_GE|WO_LT|WO_LE);
+
+  assert( pNew->u.btree.nEq<=pProbe->nColumn );
+  if( pNew->u.btree.nEq < pProbe->nColumn ){
+    iCol = pProbe->aiColumn[pNew->u.btree.nEq];
+    nRowEst = whereCost(pProbe->aiRowEst[pNew->u.btree.nEq+1]);
+    if( nRowEst==0 && pProbe->onError==OE_None ) nRowEst = 1;
+  }else{
+    iCol = -1;
+    nRowEst = 0;
+  }
+  pTerm = whereScanInit(&scan, pBuilder->pWC, pSrc->iCursor, iCol,
+                        opMask, pProbe);
+  saved_nEq = pNew->u.btree.nEq;
+  saved_nLTerm = pNew->nLTerm;
+  saved_wsFlags = pNew->wsFlags;
+  saved_prereq = pNew->prereq;
+  saved_nOut = pNew->nOut;
+  pNew->rSetup = 0;
+  rLogSize = estLog(whereCost(pProbe->aiRowEst[0]));
+  for(; rc==SQLITE_OK && pTerm!=0; pTerm = whereScanNext(&scan)){
+    int nIn = 0;
+    if( pTerm->prereqRight & pNew->maskSelf ) continue;
+    if( (pTerm->eOperator==WO_ISNULL || (pTerm->wtFlags&TERM_VNULL)!=0)
+     && (iCol<0 || pSrc->pTab->aCol[iCol].notNull)
+    ){
+      continue; /* ignore IS [NOT] NULL constraints on NOT NULL columns */
+    }
+    pNew->wsFlags = saved_wsFlags;
+    pNew->u.btree.nEq = saved_nEq;
+    pNew->nLTerm = saved_nLTerm;
+    if( whereLoopResize(db, pNew, pNew->nLTerm+1) ) break; /* OOM */
+    pNew->aLTerm[pNew->nLTerm++] = pTerm;
+    pNew->prereq = (saved_prereq | pTerm->prereqRight) & ~pNew->maskSelf;
+    pNew->rRun = rLogSize; /* Baseline cost is log2(N).  Adjustments below */
+    if( pTerm->eOperator & WO_IN ){
+      Expr *pExpr = pTerm->pExpr;
+      pNew->wsFlags |= WHERE_COLUMN_IN;
+      if( ExprHasProperty(pExpr, EP_xIsSelect) ){
+        /* "x IN (SELECT ...)":  TUNING: the SELECT returns 25 rows */
+        nIn = 46;  assert( 46==whereCost(25) );
+      }else if( ALWAYS(pExpr->x.pList && pExpr->x.pList->nExpr) ){
+        /* "x IN (value, value, ...)" */
+        nIn = whereCost(pExpr->x.pList->nExpr);
+      }
+      pNew->rRun += nIn;
+      pNew->u.btree.nEq++;
+      pNew->nOut = nRowEst + nInMul + nIn;
+    }else if( pTerm->eOperator & (WO_EQ) ){
+      assert( (pNew->wsFlags & (WHERE_COLUMN_NULL|WHERE_COLUMN_IN))!=0
+                  || nInMul==0 );
+      pNew->wsFlags |= WHERE_COLUMN_EQ;
+      if( iCol<0  
+       || (pProbe->onError!=OE_None && nInMul==0
+           && pNew->u.btree.nEq==pProbe->nColumn-1)
+      ){
+        assert( (pNew->wsFlags & WHERE_COLUMN_IN)==0 || iCol<0 );
+        pNew->wsFlags |= WHERE_ONEROW;
+      }
+      pNew->u.btree.nEq++;
+      pNew->nOut = nRowEst + nInMul;
+    }else if( pTerm->eOperator & (WO_ISNULL) ){
+      pNew->wsFlags |= WHERE_COLUMN_NULL;
+      pNew->u.btree.nEq++;
+      /* TUNING: IS NULL selects 2 rows */
+      nIn = 10;  assert( 10==whereCost(2) );
+      pNew->nOut = nRowEst + nInMul + nIn;
+    }else if( pTerm->eOperator & (WO_GT|WO_GE) ){
+      testcase( pTerm->eOperator & WO_GT );
+      testcase( pTerm->eOperator & WO_GE );
+      pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_BTM_LIMIT;
+      pBtm = pTerm;
+      pTop = 0;
+    }else{
+      assert( pTerm->eOperator & (WO_LT|WO_LE) );
+      testcase( pTerm->eOperator & WO_LT );
+      testcase( pTerm->eOperator & WO_LE );
+      pNew->wsFlags |= WHERE_COLUMN_RANGE|WHERE_TOP_LIMIT;
+      pTop = pTerm;
+      pBtm = (pNew->wsFlags & WHERE_BTM_LIMIT)!=0 ?
+                     pNew->aLTerm[pNew->nLTerm-2] : 0;
+    }
+    if( pNew->wsFlags & WHERE_COLUMN_RANGE ){
+      /* Adjust nOut and rRun for STAT3 range values */
+      WhereCost rDiv;
+      whereRangeScanEst(pParse, pProbe, pNew->u.btree.nEq,
+                        pBtm, pTop, &rDiv);
+      pNew->nOut = saved_nOut>rDiv+10 ? saved_nOut - rDiv : 10;
+    }
+#ifdef SQLITE_ENABLE_STAT3
+    if( pNew->u.btree.nEq==1 && pProbe->nSample
+     &&  OptimizationEnabled(db, SQLITE_Stat3) ){
+      tRowcnt nOut = 0;
+      if( (pTerm->eOperator & (WO_EQ|WO_ISNULL))!=0 ){
+        testcase( pTerm->eOperator & WO_EQ );
+        testcase( pTerm->eOperator & WO_ISNULL );
+        rc = whereEqualScanEst(pParse, pProbe, pTerm->pExpr->pRight, &nOut);
+      }else if( (pTerm->eOperator & WO_IN)
+             &&  !ExprHasProperty(pTerm->pExpr, EP_xIsSelect)  ){
+        rc = whereInScanEst(pParse, pProbe, pTerm->pExpr->x.pList, &nOut);
+      }
+      assert( nOut==0 || rc==SQLITE_OK );
+      if( nOut ) pNew->nOut = whereCost(nOut);
+    }
+#endif
+    if( (pNew->wsFlags & (WHERE_IDX_ONLY|WHERE_IPK))==0 ){
+      /* Each row involves a step of the index, then a binary search of
+      ** the main table */
+      pNew->rRun =  whereCostAdd(pNew->rRun, rLogSize>27 ? rLogSize-17 : 10);
+    }
+    /* Step cost for each output row */
+    pNew->rRun = whereCostAdd(pNew->rRun, pNew->nOut);
+    /* TBD: Adjust nOut for additional constraints */
+    rc = whereLoopInsert(pBuilder, pNew);
+    if( (pNew->wsFlags & WHERE_TOP_LIMIT)==0
+     && pNew->u.btree.nEq<(pProbe->nColumn + (pProbe->zName!=0))
+    ){
+      whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, nInMul+nIn);
+    }
+  }
+  pNew->prereq = saved_prereq;
+  pNew->u.btree.nEq = saved_nEq;
+  pNew->wsFlags = saved_wsFlags;
+  pNew->nOut = saved_nOut;
+  pNew->nLTerm = saved_nLTerm;
+  return rc;
+}
+
+/*
+** Return True if it is possible that pIndex might be useful in
+** implementing the ORDER BY clause in pBuilder.
+**
+** Return False if pBuilder does not contain an ORDER BY clause or
+** if there is no way for pIndex to be useful in implementing that
+** ORDER BY clause.
+*/
+static int indexMightHelpWithOrderBy(
+  WhereLoopBuilder *pBuilder,
+  Index *pIndex,
+  int iCursor
+){
+  ExprList *pOB;
+  int ii, jj;
+
+  if( pIndex->bUnordered ) return 0;
+  if( (pOB = pBuilder->pWInfo->pOrderBy)==0 ) return 0;
+  for(ii=0; ii<pOB->nExpr; ii++){
+    Expr *pExpr = sqlite3ExprSkipCollate(pOB->a[ii].pExpr);
+    if( pExpr->op!=TK_COLUMN ) return 0;
+    if( pExpr->iTable==iCursor ){
+      for(jj=0; jj<pIndex->nColumn; jj++){
+        if( pExpr->iColumn==pIndex->aiColumn[jj] ) return 1;
+      }
+    }
+  }
+  return 0;
+}
+
+/*
+** Return a bitmask where 1s indicate that the corresponding column of
+** the table is used by an index.  Only the first 63 columns are considered.
+*/
+static Bitmask columnsInIndex(Index *pIdx){
+  Bitmask m = 0;
+  int j;
+  for(j=pIdx->nColumn-1; j>=0; j--){
+    int x = pIdx->aiColumn[j];
+    assert( x>=0 );
+    testcase( x==BMS-1 );
+    testcase( x==BMS-2 );
+    if( x<BMS-1 ) m |= MASKBIT(x);
+  }
+  return m;
+}
+
+/* Check to see if a partial index with pPartIndexWhere can be used
+** in the current query.  Return true if it can be and false if not.
+*/
+static int whereUsablePartialIndex(int iTab, WhereClause *pWC, Expr *pWhere){
+  int i;
+  WhereTerm *pTerm;
+  for(i=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){
+    if( sqlite3ExprImpliesExpr(pTerm->pExpr, pWhere, iTab) ) return 1;
+  }
+  return 0;
+}
+
+/*
+** Add all WhereLoop objects for a single table of the join where the table
+** is idenfied by pBuilder->pNew->iTab.  That table is guaranteed to be
+** a b-tree table, not a virtual table.
+*/
+static int whereLoopAddBtree(
+  WhereLoopBuilder *pBuilder, /* WHERE clause information */
+  Bitmask mExtra              /* Extra prerequesites for using this table */
+){
+  WhereInfo *pWInfo;          /* WHERE analysis context */
+  Index *pProbe;              /* An index we are evaluating */
+  Index sPk;                  /* A fake index object for the primary key */
+  tRowcnt aiRowEstPk[2];      /* The aiRowEst[] value for the sPk index */
+  int aiColumnPk = -1;        /* The aColumn[] value for the sPk index */
+  SrcList *pTabList;          /* The FROM clause */
+  struct SrcList_item *pSrc;  /* The FROM clause btree term to add */
+  WhereLoop *pNew;            /* Template WhereLoop object */
+  int rc = SQLITE_OK;         /* Return code */
+  int iSortIdx = 1;           /* Index number */
+  int b;                      /* A boolean value */
+  WhereCost rSize;            /* number of rows in the table */
+  WhereCost rLogSize;         /* Logarithm of the number of rows in the table */
+  WhereClause *pWC;           /* The parsed WHERE clause */
+  
+  pNew = pBuilder->pNew;
+  pWInfo = pBuilder->pWInfo;
+  pTabList = pWInfo->pTabList;
+  pSrc = pTabList->a + pNew->iTab;
+  pWC = pBuilder->pWC;
+  assert( !IsVirtual(pSrc->pTab) );
+
+  if( pSrc->pIndex ){
+    /* An INDEXED BY clause specifies a particular index to use */
+    pProbe = pSrc->pIndex;
+  }else{
+    /* There is no INDEXED BY clause.  Create a fake Index object in local
+    ** variable sPk to represent the rowid primary key index.  Make this
+    ** fake index the first in a chain of Index objects with all of the real
+    ** indices to follow */
+    Index *pFirst;                  /* First of real indices on the table */
+    memset(&sPk, 0, sizeof(Index));
+    sPk.nColumn = 1;
+    sPk.aiColumn = &aiColumnPk;
+    sPk.aiRowEst = aiRowEstPk;
+    sPk.onError = OE_Replace;
+    sPk.pTable = pSrc->pTab;
+    aiRowEstPk[0] = pSrc->pTab->nRowEst;
+    aiRowEstPk[1] = 1;
+    pFirst = pSrc->pTab->pIndex;
+    if( pSrc->notIndexed==0 ){
+      /* The real indices of the table are only considered if the
+      ** NOT INDEXED qualifier is omitted from the FROM clause */
+      sPk.pNext = pFirst;
+    }
+    pProbe = &sPk;
+  }
+  rSize = whereCost(pSrc->pTab->nRowEst);
+  rLogSize = estLog(rSize);
+
+#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
+  /* Automatic indexes */
+  if( !pBuilder->pOrSet
+   && (pWInfo->pParse->db->flags & SQLITE_AutoIndex)!=0
+   && pSrc->pIndex==0
+   && !pSrc->viaCoroutine
+   && !pSrc->notIndexed
+   && !pSrc->isCorrelated
+  ){
+    /* Generate auto-index WhereLoops */
+    WhereTerm *pTerm;
+    WhereTerm *pWCEnd = pWC->a + pWC->nTerm;
+    for(pTerm=pWC->a; rc==SQLITE_OK && pTerm<pWCEnd; pTerm++){
+      if( pTerm->prereqRight & pNew->maskSelf ) continue;
+      if( termCanDriveIndex(pTerm, pSrc, 0) ){
+        pNew->u.btree.nEq = 1;
+        pNew->u.btree.pIndex = 0;
+        pNew->nLTerm = 1;
+        pNew->aLTerm[0] = pTerm;
+        /* TUNING: One-time cost for computing the automatic index is
+        ** approximately 7*N*log2(N) where N is the number of rows in
+        ** the table being indexed. */
+        pNew->rSetup = rLogSize + rSize + 28;  assert( 28==whereCost(7) );
+        /* TUNING: Each index lookup yields 20 rows in the table.  This
+        ** is more than the usual guess of 10 rows, since we have no way
+        ** of knowning how selective the index will ultimately be.  It would
+        ** not be unreasonable to make this value much larger. */
+        pNew->nOut = 43;  assert( 43==whereCost(20) );
+        pNew->rRun = whereCostAdd(rLogSize,pNew->nOut);
+        pNew->wsFlags = WHERE_AUTO_INDEX;
+        pNew->prereq = mExtra | pTerm->prereqRight;
+        rc = whereLoopInsert(pBuilder, pNew);
+      }
+    }
+  }
+#endif /* SQLITE_OMIT_AUTOMATIC_INDEX */
+
+  /* Loop over all indices
+  */
+  for(; rc==SQLITE_OK && pProbe; pProbe=pProbe->pNext, iSortIdx++){
+    if( pProbe->pPartIdxWhere!=0
+     && !whereUsablePartialIndex(pNew->iTab, pWC, pProbe->pPartIdxWhere) ){
+      continue;  /* Partial index inappropriate for this query */
+    }
+    pNew->u.btree.nEq = 0;
+    pNew->nLTerm = 0;
+    pNew->iSortIdx = 0;
+    pNew->rSetup = 0;
+    pNew->prereq = mExtra;
+    pNew->nOut = rSize;
+    pNew->u.btree.pIndex = pProbe;
+    b = indexMightHelpWithOrderBy(pBuilder, pProbe, pSrc->iCursor);
+    /* The ONEPASS_DESIRED flags never occurs together with ORDER BY */
+    assert( (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0 || b==0 );
+    if( pProbe->tnum<=0 ){
+      /* Integer primary key index */
+      pNew->wsFlags = WHERE_IPK;
+
+      /* Full table scan */
+      pNew->iSortIdx = b ? iSortIdx : 0;
+      /* TUNING: Cost of full table scan is 3*(N + log2(N)).
+      **  +  The extra 3 factor is to encourage the use of indexed lookups
+      **     over full scans.  A smaller constant 2 is used for covering
+      **     index scans so that a covering index scan will be favored over
+      **     a table scan. */
+      pNew->rRun = whereCostAdd(rSize,rLogSize) + 16;
+      rc = whereLoopInsert(pBuilder, pNew);
+      if( rc ) break;
+    }else{
+      Bitmask m = pSrc->colUsed & ~columnsInIndex(pProbe);
+      pNew->wsFlags = (m==0) ? (WHERE_IDX_ONLY|WHERE_INDEXED) : WHERE_INDEXED;
+
+      /* Full scan via index */
+      if( b
+       || ( m==0
+         && pProbe->bUnordered==0
+         && (pWInfo->wctrlFlags & WHERE_ONEPASS_DESIRED)==0
+         && sqlite3GlobalConfig.bUseCis
+         && OptimizationEnabled(pWInfo->pParse->db, SQLITE_CoverIdxScan)
+          )
+      ){
+        pNew->iSortIdx = b ? iSortIdx : 0;
+        if( m==0 ){
+          /* TUNING: Cost of a covering index scan is 2*(N + log2(N)).
+          **  +  The extra 2 factor is to encourage the use of indexed lookups
+          **     over index scans.  A table scan uses a factor of 3 so that
+          **     index scans are favored over table scans.
+          **  +  If this covering index might also help satisfy the ORDER BY
+          **     clause, then the cost is fudged down slightly so that this
+          **     index is favored above other indices that have no hope of
+          **     helping with the ORDER BY. */
+          pNew->rRun = 10 + whereCostAdd(rSize,rLogSize) - b;
+        }else{
+          assert( b!=0 ); 
+          /* TUNING: Cost of scanning a non-covering index is (N+1)*log2(N)
+          ** which we will simplify to just N*log2(N) */
+          pNew->rRun = rSize + rLogSize;
         }
-        sqlite3DbFree(db, pInfo);
+        rc = whereLoopInsert(pBuilder, pNew);
+        if( rc ) break;
+      }
+    }
+    rc = whereLoopAddBtreeIndex(pBuilder, pSrc, pProbe, 0);
+
+    /* If there was an INDEXED BY clause, then only that one index is
+    ** considered. */
+    if( pSrc->pIndex ) break;
+  }
+  return rc;
+}
+
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+/*
+** Add all WhereLoop objects for a table of the join identified by
+** pBuilder->pNew->iTab.  That table is guaranteed to be a virtual table.
+*/
+static int whereLoopAddVirtual(
+  WhereLoopBuilder *pBuilder   /* WHERE clause information */
+){
+  WhereInfo *pWInfo;           /* WHERE analysis context */
+  Parse *pParse;               /* The parsing context */
+  WhereClause *pWC;            /* The WHERE clause */
+  struct SrcList_item *pSrc;   /* The FROM clause term to search */
+  Table *pTab;
+  sqlite3 *db;
+  sqlite3_index_info *pIdxInfo;
+  struct sqlite3_index_constraint *pIdxCons;
+  struct sqlite3_index_constraint_usage *pUsage;
+  WhereTerm *pTerm;
+  int i, j;
+  int iTerm, mxTerm;
+  int nConstraint;
+  int seenIn = 0;              /* True if an IN operator is seen */
+  int seenVar = 0;             /* True if a non-constant constraint is seen */
+  int iPhase;                  /* 0: const w/o IN, 1: const, 2: no IN,  2: IN */
+  WhereLoop *pNew;
+  int rc = SQLITE_OK;
+
+  pWInfo = pBuilder->pWInfo;
+  pParse = pWInfo->pParse;
+  db = pParse->db;
+  pWC = pBuilder->pWC;
+  pNew = pBuilder->pNew;
+  pSrc = &pWInfo->pTabList->a[pNew->iTab];
+  pTab = pSrc->pTab;
+  assert( IsVirtual(pTab) );
+  pIdxInfo = allocateIndexInfo(pParse, pWC, pSrc, pBuilder->pOrderBy);
+  if( pIdxInfo==0 ) return SQLITE_NOMEM;
+  pNew->prereq = 0;
+  pNew->rSetup = 0;
+  pNew->wsFlags = WHERE_VIRTUALTABLE;
+  pNew->nLTerm = 0;
+  pNew->u.vtab.needFree = 0;
+  pUsage = pIdxInfo->aConstraintUsage;
+  nConstraint = pIdxInfo->nConstraint;
+  if( whereLoopResize(db, pNew, nConstraint) ){
+    sqlite3DbFree(db, pIdxInfo);
+    return SQLITE_NOMEM;
+  }
+
+  for(iPhase=0; iPhase<=3; iPhase++){
+    if( !seenIn && (iPhase&1)!=0 ){
+      iPhase++;
+      if( iPhase>3 ) break;
+    }
+    if( !seenVar && iPhase>1 ) break;
+    pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
+    for(i=0; i<pIdxInfo->nConstraint; i++, pIdxCons++){
+      j = pIdxCons->iTermOffset;
+      pTerm = &pWC->a[j];
+      switch( iPhase ){
+        case 0:    /* Constants without IN operator */
+          pIdxCons->usable = 0;
+          if( (pTerm->eOperator & WO_IN)!=0 ){
+            seenIn = 1;
+          }
+          if( pTerm->prereqRight!=0 ){
+            seenVar = 1;
+          }else if( (pTerm->eOperator & WO_IN)==0 ){
+            pIdxCons->usable = 1;
+          }
+          break;
+        case 1:    /* Constants with IN operators */
+          assert( seenIn );
+          pIdxCons->usable = (pTerm->prereqRight==0);
+          break;
+        case 2:    /* Variables without IN */
+          assert( seenVar );
+          pIdxCons->usable = (pTerm->eOperator & WO_IN)==0;
+          break;
+        default:   /* Variables with IN */
+          assert( seenVar && seenIn );
+          pIdxCons->usable = 1;
+          break;
       }
-      if( pWInfo->a[i].plan.wsFlags & WHERE_TEMP_INDEX ){
-        Index *pIdx = pWInfo->a[i].plan.u.pIdx;
-        if( pIdx ){
-          sqlite3DbFree(db, pIdx->zColAff);
-          sqlite3DbFree(db, pIdx);
+    }
+    memset(pUsage, 0, sizeof(pUsage[0])*pIdxInfo->nConstraint);
+    if( pIdxInfo->needToFreeIdxStr ) sqlite3_free(pIdxInfo->idxStr);
+    pIdxInfo->idxStr = 0;
+    pIdxInfo->idxNum = 0;
+    pIdxInfo->needToFreeIdxStr = 0;
+    pIdxInfo->orderByConsumed = 0;
+    pIdxInfo->estimatedCost = SQLITE_BIG_DBL / (double)2;
+    rc = vtabBestIndex(pParse, pTab, pIdxInfo);
+    if( rc ) goto whereLoopAddVtab_exit;
+    pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint;
+    pNew->prereq = 0;
+    mxTerm = -1;
+    assert( pNew->nLSlot>=nConstraint );
+    for(i=0; i<nConstraint; i++) pNew->aLTerm[i] = 0;
+    pNew->u.vtab.omitMask = 0;
+    for(i=0; i<nConstraint; i++, pIdxCons++){
+      if( (iTerm = pUsage[i].argvIndex - 1)>=0 ){
+        j = pIdxCons->iTermOffset;
+        if( iTerm>=nConstraint
+         || j<0
+         || j>=pWC->nTerm
+         || pNew->aLTerm[iTerm]!=0
+        ){
+          rc = SQLITE_ERROR;
+          sqlite3ErrorMsg(pParse, "%s.xBestIndex() malfunction", pTab->zName);
+          goto whereLoopAddVtab_exit;
+        }
+        testcase( iTerm==nConstraint-1 );
+        testcase( j==0 );
+        testcase( j==pWC->nTerm-1 );
+        pTerm = &pWC->a[j];
+        pNew->prereq |= pTerm->prereqRight;
+        assert( iTerm<pNew->nLSlot );
+        pNew->aLTerm[iTerm] = pTerm;
+        if( iTerm>mxTerm ) mxTerm = iTerm;
+        testcase( iTerm==15 );
+        testcase( iTerm==16 );
+        if( iTerm<16 && pUsage[i].omit ) pNew->u.vtab.omitMask |= 1<<iTerm;
+        if( (pTerm->eOperator & WO_IN)!=0 ){
+          if( pUsage[i].omit==0 ){
+            /* Do not attempt to use an IN constraint if the virtual table
+            ** says that the equivalent EQ constraint cannot be safely omitted.
+            ** If we do attempt to use such a constraint, some rows might be
+            ** repeated in the output. */
+            break;
+          }
+          /* A virtual table that is constrained by an IN clause may not
+          ** consume the ORDER BY clause because (1) the order of IN terms
+          ** is not necessarily related to the order of output terms and
+          ** (2) Multiple outputs from a single IN value will not merge
+          ** together.  */
+          pIdxInfo->orderByConsumed = 0;
         }
       }
     }
-    whereClauseClear(pWInfo->pWC);
-    sqlite3DbFree(db, pWInfo);
+    if( i>=nConstraint ){
+      pNew->nLTerm = mxTerm+1;
+      assert( pNew->nLTerm<=pNew->nLSlot );
+      pNew->u.vtab.idxNum = pIdxInfo->idxNum;
+      pNew->u.vtab.needFree = pIdxInfo->needToFreeIdxStr;
+      pIdxInfo->needToFreeIdxStr = 0;
+      pNew->u.vtab.idxStr = pIdxInfo->idxStr;
+      pNew->u.vtab.isOrdered = (u8)((pIdxInfo->nOrderBy!=0)
+                                     && pIdxInfo->orderByConsumed);
+      pNew->rSetup = 0;
+      pNew->rRun = whereCostFromDouble(pIdxInfo->estimatedCost);
+      /* TUNING: Every virtual table query returns 25 rows */
+      pNew->nOut = 46;  assert( 46==whereCost(25) );
+      whereLoopInsert(pBuilder, pNew);
+      if( pNew->u.vtab.needFree ){
+        sqlite3_free(pNew->u.vtab.idxStr);
+        pNew->u.vtab.needFree = 0;
+      }
+    }
+  }  
+
+whereLoopAddVtab_exit:
+  if( pIdxInfo->needToFreeIdxStr ) sqlite3_free(pIdxInfo->idxStr);
+  sqlite3DbFree(db, pIdxInfo);
+  return rc;
+}
+#endif /* SQLITE_OMIT_VIRTUALTABLE */
+
+/*
+** Add WhereLoop entries to handle OR terms.  This works for either
+** btrees or virtual tables.
+*/
+static int whereLoopAddOr(WhereLoopBuilder *pBuilder, Bitmask mExtra){
+  WhereInfo *pWInfo = pBuilder->pWInfo;
+  WhereClause *pWC;
+  WhereLoop *pNew;
+  WhereTerm *pTerm, *pWCEnd;
+  int rc = SQLITE_OK;
+  int iCur;
+  WhereClause tempWC;
+  WhereLoopBuilder sSubBuild;
+  WhereOrSet sSum, sCur, sPrev;
+  struct SrcList_item *pItem;
+  
+  pWC = pBuilder->pWC;
+  if( pWInfo->wctrlFlags & WHERE_AND_ONLY ) return SQLITE_OK;
+  pWCEnd = pWC->a + pWC->nTerm;
+  pNew = pBuilder->pNew;
+  memset(&sSum, 0, sizeof(sSum));
+
+  for(pTerm=pWC->a; pTerm<pWCEnd && rc==SQLITE_OK; pTerm++){
+    if( (pTerm->eOperator & WO_OR)!=0
+     && (pTerm->u.pOrInfo->indexable & pNew->maskSelf)!=0 
+    ){
+      WhereClause * const pOrWC = &pTerm->u.pOrInfo->wc;
+      WhereTerm * const pOrWCEnd = &pOrWC->a[pOrWC->nTerm];
+      WhereTerm *pOrTerm;
+      int once = 1;
+      int i, j;
+    
+      pItem = pWInfo->pTabList->a + pNew->iTab;
+      iCur = pItem->iCursor;
+      sSubBuild = *pBuilder;
+      sSubBuild.pOrderBy = 0;
+      sSubBuild.pOrSet = &sCur;
+
+      for(pOrTerm=pOrWC->a; pOrTerm<pOrWCEnd; pOrTerm++){
+        if( (pOrTerm->eOperator & WO_AND)!=0 ){
+          sSubBuild.pWC = &pOrTerm->u.pAndInfo->wc;
+        }else if( pOrTerm->leftCursor==iCur ){
+          tempWC.pWInfo = pWC->pWInfo;
+          tempWC.pOuter = pWC;
+          tempWC.op = TK_AND;
+          tempWC.nTerm = 1;
+          tempWC.a = pOrTerm;
+          sSubBuild.pWC = &tempWC;
+        }else{
+          continue;
+        }
+        sCur.n = 0;
+#ifndef SQLITE_OMIT_VIRTUALTABLE
+        if( IsVirtual(pItem->pTab) ){
+          rc = whereLoopAddVirtual(&sSubBuild);
+          for(i=0; i<sCur.n; i++) sCur.a[i].prereq |= mExtra;
+        }else
+#endif
+        {
+          rc = whereLoopAddBtree(&sSubBuild, mExtra);
+        }
+        assert( rc==SQLITE_OK || sCur.n==0 );
+        if( sCur.n==0 ){
+          sSum.n = 0;
+          break;
+        }else if( once ){
+          whereOrMove(&sSum, &sCur);
+          once = 0;
+        }else{
+          whereOrMove(&sPrev, &sSum);
+          sSum.n = 0;
+          for(i=0; i<sPrev.n; i++){
+            for(j=0; j<sCur.n; j++){
+              whereOrInsert(&sSum, sPrev.a[i].prereq | sCur.a[j].prereq,
+                            whereCostAdd(sPrev.a[i].rRun, sCur.a[j].rRun),
+                            whereCostAdd(sPrev.a[i].nOut, sCur.a[j].nOut));
+            }
+          }
+        }
+      }
+      pNew->nLTerm = 1;
+      pNew->aLTerm[0] = pTerm;
+      pNew->wsFlags = WHERE_MULTI_OR;
+      pNew->rSetup = 0;
+      pNew->iSortIdx = 0;
+      memset(&pNew->u, 0, sizeof(pNew->u));
+      for(i=0; rc==SQLITE_OK && i<sSum.n; i++){
+        /* TUNING: Multiple by 3.5 for the secondary table lookup */
+        pNew->rRun = sSum.a[i].rRun + 18;
+        pNew->nOut = sSum.a[i].nOut;
+        pNew->prereq = sSum.a[i].prereq;
+        rc = whereLoopInsert(pBuilder, pNew);
+      }
+    }
+  }
+  return rc;
+}
+
+/*
+** Add all WhereLoop objects for all tables 
+*/
+static int whereLoopAddAll(WhereLoopBuilder *pBuilder){
+  WhereInfo *pWInfo = pBuilder->pWInfo;
+  Bitmask mExtra = 0;
+  Bitmask mPrior = 0;
+  int iTab;
+  SrcList *pTabList = pWInfo->pTabList;
+  struct SrcList_item *pItem;
+  sqlite3 *db = pWInfo->pParse->db;
+  int nTabList = pWInfo->nLevel;
+  int rc = SQLITE_OK;
+  u8 priorJoinType = 0;
+  WhereLoop *pNew;
+
+  /* Loop over the tables in the join, from left to right */
+  pNew = pBuilder->pNew;
+  whereLoopInit(pNew);
+  for(iTab=0, pItem=pTabList->a; iTab<nTabList; iTab++, pItem++){
+    pNew->iTab = iTab;
+    pNew->maskSelf = getMask(&pWInfo->sMaskSet, pItem->iCursor);
+    if( ((pItem->jointype|priorJoinType) & (JT_LEFT|JT_CROSS))!=0 ){
+      mExtra = mPrior;
+    }
+    priorJoinType = pItem->jointype;
+    if( IsVirtual(pItem->pTab) ){
+      rc = whereLoopAddVirtual(pBuilder);
+    }else{
+      rc = whereLoopAddBtree(pBuilder, mExtra);
+    }
+    if( rc==SQLITE_OK ){
+      rc = whereLoopAddOr(pBuilder, mExtra);
+    }
+    mPrior |= pNew->maskSelf;
+    if( rc || db->mallocFailed ) break;
+  }
+  whereLoopClear(db, pNew);
+  return rc;
+}
+
+/*
+** Examine a WherePath (with the addition of the extra WhereLoop of the 5th
+** parameters) to see if it outputs rows in the requested ORDER BY
+** (or GROUP BY) without requiring a separate sort operation.  Return:
+** 
+**    0:  ORDER BY is not satisfied.  Sorting required
+**    1:  ORDER BY is satisfied.      Omit sorting
+**   -1:  Unknown at this time
+**
+** Note that processing for WHERE_GROUPBY and WHERE_DISTINCTBY is not as
+** strict.  With GROUP BY and DISTINCT the only requirement is that
+** equivalent rows appear immediately adjacent to one another.  GROUP BY
+** and DISTINT do not require rows to appear in any particular order as long
+** as equivelent rows are grouped together.  Thus for GROUP BY and DISTINCT
+** the pOrderBy terms can be matched in any order.  With ORDER BY, the 
+** pOrderBy terms must be matched in strict left-to-right order.
+*/
+static int wherePathSatisfiesOrderBy(
+  WhereInfo *pWInfo,    /* The WHERE clause */
+  ExprList *pOrderBy,   /* ORDER BY or GROUP BY or DISTINCT clause to check */
+  WherePath *pPath,     /* The WherePath to check */
+  u16 wctrlFlags,       /* Might contain WHERE_GROUPBY or WHERE_DISTINCTBY */
+  u16 nLoop,            /* Number of entries in pPath->aLoop[] */
+  WhereLoop *pLast,     /* Add this WhereLoop to the end of pPath->aLoop[] */
+  Bitmask *pRevMask     /* OUT: Mask of WhereLoops to run in reverse order */
+){
+  u8 revSet;            /* True if rev is known */
+  u8 rev;               /* Composite sort order */
+  u8 revIdx;            /* Index sort order */
+  u8 isOrderDistinct;   /* All prior WhereLoops are order-distinct */
+  u8 distinctColumns;   /* True if the loop has UNIQUE NOT NULL columns */
+  u8 isMatch;           /* iColumn matches a term of the ORDER BY clause */
+  u16 nColumn;          /* Number of columns in pIndex */
+  u16 nOrderBy;         /* Number terms in the ORDER BY clause */
+  int iLoop;            /* Index of WhereLoop in pPath being processed */
+  int i, j;             /* Loop counters */
+  int iCur;             /* Cursor number for current WhereLoop */
+  int iColumn;          /* A column number within table iCur */
+  WhereLoop *pLoop = 0; /* Current WhereLoop being processed. */
+  WhereTerm *pTerm;     /* A single term of the WHERE clause */
+  Expr *pOBExpr;        /* An expression from the ORDER BY clause */
+  CollSeq *pColl;       /* COLLATE function from an ORDER BY clause term */
+  Index *pIndex;        /* The index associated with pLoop */
+  sqlite3 *db = pWInfo->pParse->db;  /* Database connection */
+  Bitmask obSat = 0;    /* Mask of ORDER BY terms satisfied so far */
+  Bitmask obDone;       /* Mask of all ORDER BY terms */
+  Bitmask orderDistinctMask;  /* Mask of all well-ordered loops */
+  Bitmask ready;              /* Mask of inner loops */
+
+  /*
+  ** We say the WhereLoop is "one-row" if it generates no more than one
+  ** row of output.  A WhereLoop is one-row if all of the following are true:
+  **  (a) All index columns match with WHERE_COLUMN_EQ.
+  **  (b) The index is unique
+  ** Any WhereLoop with an WHERE_COLUMN_EQ constraint on the rowid is one-row.
+  ** Every one-row WhereLoop will have the WHERE_ONEROW bit set in wsFlags.
+  **
+  ** We say the WhereLoop is "order-distinct" if the set of columns from
+  ** that WhereLoop that are in the ORDER BY clause are different for every
+  ** row of the WhereLoop.  Every one-row WhereLoop is automatically
+  ** order-distinct.   A WhereLoop that has no columns in the ORDER BY clause
+  ** is not order-distinct. To be order-distinct is not quite the same as being
+  ** UNIQUE since a UNIQUE column or index can have multiple rows that 
+  ** are NULL and NULL values are equivalent for the purpose of order-distinct.
+  ** To be order-distinct, the columns must be UNIQUE and NOT NULL.
+  **
+  ** The rowid for a table is always UNIQUE and NOT NULL so whenever the
+  ** rowid appears in the ORDER BY clause, the corresponding WhereLoop is
+  ** automatically order-distinct.
+  */
+
+  assert( pOrderBy!=0 );
+
+  /* Sortability of virtual tables is determined by the xBestIndex method
+  ** of the virtual table itself */
+  if( pLast->wsFlags & WHERE_VIRTUALTABLE ){
+    testcase( nLoop>0 );  /* True when outer loops are one-row and match 
+                          ** no ORDER BY terms */
+    return pLast->u.vtab.isOrdered;
+  }
+  if( nLoop && OptimizationDisabled(db, SQLITE_OrderByIdxJoin) ) return 0;
+
+  nOrderBy = pOrderBy->nExpr;
+  testcase( nOrderBy==BMS-1 );
+  if( nOrderBy>BMS-1 ) return 0;  /* Cannot optimize overly large ORDER BYs */
+  isOrderDistinct = 1;
+  obDone = MASKBIT(nOrderBy)-1;
+  orderDistinctMask = 0;
+  ready = 0;
+  for(iLoop=0; isOrderDistinct && obSat<obDone && iLoop<=nLoop; iLoop++){
+    if( iLoop>0 ) ready |= pLoop->maskSelf;
+    pLoop = iLoop<nLoop ? pPath->aLoop[iLoop] : pLast;
+    assert( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0 );
+    iCur = pWInfo->pTabList->a[pLoop->iTab].iCursor;
+
+    /* Mark off any ORDER BY term X that is a column in the table of
+    ** the current loop for which there is term in the WHERE
+    ** clause of the form X IS NULL or X=? that reference only outer
+    ** loops.
+    */
+    for(i=0; i<nOrderBy; i++){
+      if( MASKBIT(i) & obSat ) continue;
+      pOBExpr = sqlite3ExprSkipCollate(pOrderBy->a[i].pExpr);
+      if( pOBExpr->op!=TK_COLUMN ) continue;
+      if( pOBExpr->iTable!=iCur ) continue;
+      pTerm = findTerm(&pWInfo->sWC, iCur, pOBExpr->iColumn,
+                       ~ready, WO_EQ|WO_ISNULL, 0);
+      if( pTerm==0 ) continue;
+      if( (pTerm->eOperator&WO_EQ)!=0 && pOBExpr->iColumn>=0 ){
+        const char *z1, *z2;
+        pColl = sqlite3ExprCollSeq(pWInfo->pParse, pOrderBy->a[i].pExpr);
+        if( !pColl ) pColl = db->pDfltColl;
+        z1 = pColl->zName;
+        pColl = sqlite3ExprCollSeq(pWInfo->pParse, pTerm->pExpr);
+        if( !pColl ) pColl = db->pDfltColl;
+        z2 = pColl->zName;
+        if( sqlite3StrICmp(z1, z2)!=0 ) continue;
+      }
+      obSat |= MASKBIT(i);
+    }
+
+    if( (pLoop->wsFlags & WHERE_ONEROW)==0 ){
+      if( pLoop->wsFlags & WHERE_IPK ){
+        pIndex = 0;
+        nColumn = 0;
+      }else if( (pIndex = pLoop->u.btree.pIndex)==0 || pIndex->bUnordered ){
+        return 0;
+      }else{
+        nColumn = pIndex->nColumn;
+        isOrderDistinct = pIndex->onError!=OE_None;
+      }
+
+      /* Loop through all columns of the index and deal with the ones
+      ** that are not constrained by == or IN.
+      */
+      rev = revSet = 0;
+      distinctColumns = 0;
+      for(j=0; j<=nColumn; j++){
+        u8 bOnce;   /* True to run the ORDER BY search loop */
+
+        /* Skip over == and IS NULL terms */
+        if( j<pLoop->u.btree.nEq
+         && ((i = pLoop->aLTerm[j]->eOperator) & (WO_EQ|WO_ISNULL))!=0
+        ){
+          if( i & WO_ISNULL ){
+            testcase( isOrderDistinct );
+            isOrderDistinct = 0;
+          }
+          continue;  
+        }
+
+        /* Get the column number in the table (iColumn) and sort order
+        ** (revIdx) for the j-th column of the index.
+        */
+        if( j<nColumn ){
+          /* Normal index columns */
+          iColumn = pIndex->aiColumn[j];
+          revIdx = pIndex->aSortOrder[j];
+          if( iColumn==pIndex->pTable->iPKey ) iColumn = -1;
+        }else{
+          /* The ROWID column at the end */
+          assert( j==nColumn );
+          iColumn = -1;
+          revIdx = 0;
+        }
+
+        /* An unconstrained column that might be NULL means that this
+        ** WhereLoop is not well-ordered 
+        */
+        if( isOrderDistinct
+         && iColumn>=0
+         && j>=pLoop->u.btree.nEq
+         && pIndex->pTable->aCol[iColumn].notNull==0
+        ){
+          isOrderDistinct = 0;
+        }
+
+        /* Find the ORDER BY term that corresponds to the j-th column
+        ** of the index and and mark that ORDER BY term off 
+        */
+        bOnce = 1;
+        isMatch = 0;
+        for(i=0; bOnce && i<nOrderBy; i++){
+          if( MASKBIT(i) & obSat ) continue;
+          pOBExpr = sqlite3ExprSkipCollate(pOrderBy->a[i].pExpr);
+          testcase( wctrlFlags & WHERE_GROUPBY );
+          testcase( wctrlFlags & WHERE_DISTINCTBY );
+          if( (wctrlFlags & (WHERE_GROUPBY|WHERE_DISTINCTBY))==0 ) bOnce = 0;
+          if( pOBExpr->op!=TK_COLUMN ) continue;
+          if( pOBExpr->iTable!=iCur ) continue;
+          if( pOBExpr->iColumn!=iColumn ) continue;
+          if( iColumn>=0 ){
+            pColl = sqlite3ExprCollSeq(pWInfo->pParse, pOrderBy->a[i].pExpr);
+            if( !pColl ) pColl = db->pDfltColl;
+            if( sqlite3StrICmp(pColl->zName, pIndex->azColl[j])!=0 ) continue;
+          }
+          isMatch = 1;
+          break;
+        }
+        if( isMatch ){
+          if( iColumn<0 ){
+            testcase( distinctColumns==0 );
+            distinctColumns = 1;
+          }
+          obSat |= MASKBIT(i);
+          if( (pWInfo->wctrlFlags & WHERE_GROUPBY)==0 ){
+            /* Make sure the sort order is compatible in an ORDER BY clause.
+            ** Sort order is irrelevant for a GROUP BY clause. */
+            if( revSet ){
+              if( (rev ^ revIdx)!=pOrderBy->a[i].sortOrder ) return 0;
+            }else{
+              rev = revIdx ^ pOrderBy->a[i].sortOrder;
+              if( rev ) *pRevMask |= MASKBIT(iLoop);
+              revSet = 1;
+            }
+          }
+        }else{
+          /* No match found */
+          if( j==0 || j<nColumn ){
+            testcase( isOrderDistinct!=0 );
+            isOrderDistinct = 0;
+          }
+          break;
+        }
+      } /* end Loop over all index columns */
+      if( distinctColumns ){
+        testcase( isOrderDistinct==0 );
+        isOrderDistinct = 1;
+      }
+    } /* end-if not one-row */
+
+    /* Mark off any other ORDER BY terms that reference pLoop */
+    if( isOrderDistinct ){
+      orderDistinctMask |= pLoop->maskSelf;
+      for(i=0; i<nOrderBy; i++){
+        Expr *p;
+        if( MASKBIT(i) & obSat ) continue;
+        p = pOrderBy->a[i].pExpr;
+        if( (exprTableUsage(&pWInfo->sMaskSet, p)&~orderDistinctMask)==0 ){
+          obSat |= MASKBIT(i);
+        }
+      }
+    }
+  } /* End the loop over all WhereLoops from outer-most down to inner-most */
+  if( obSat==obDone ) return 1;
+  if( !isOrderDistinct ) return 0;
+  return -1;
+}
+
+#ifdef WHERETRACE_ENABLED
+/* For debugging use only: */
+static const char *wherePathName(WherePath *pPath, int nLoop, WhereLoop *pLast){
+  static char zName[65];
+  int i;
+  for(i=0; i<nLoop; i++){ zName[i] = pPath->aLoop[i]->cId; }
+  if( pLast ) zName[i++] = pLast->cId;
+  zName[i] = 0;
+  return zName;
+}
+#endif
+
+
+/*
+** Given the list of WhereLoop objects at pWInfo->pLoops, this routine
+** attempts to find the lowest cost path that visits each WhereLoop
+** once.  This path is then loaded into the pWInfo->a[].pWLoop fields.
+**
+** Assume that the total number of output rows that will need to be sorted
+** will be nRowEst (in the 10*log2 representation).  Or, ignore sorting
+** costs if nRowEst==0.
+**
+** Return SQLITE_OK on success or SQLITE_NOMEM of a memory allocation
+** error occurs.
+*/
+static int wherePathSolver(WhereInfo *pWInfo, WhereCost nRowEst){
+  int mxChoice;             /* Maximum number of simultaneous paths tracked */
+  int nLoop;                /* Number of terms in the join */
+  Parse *pParse;            /* Parsing context */
+  sqlite3 *db;              /* The database connection */
+  int iLoop;                /* Loop counter over the terms of the join */
+  int ii, jj;               /* Loop counters */
+  WhereCost rCost;             /* Cost of a path */
+  WhereCost mxCost = 0;        /* Maximum cost of a set of paths */
+  WhereCost rSortCost;         /* Cost to do a sort */
+  int nTo, nFrom;           /* Number of valid entries in aTo[] and aFrom[] */
+  WherePath *aFrom;         /* All nFrom paths at the previous level */
+  WherePath *aTo;           /* The nTo best paths at the current level */
+  WherePath *pFrom;         /* An element of aFrom[] that we are working on */
+  WherePath *pTo;           /* An element of aTo[] that we are working on */
+  WhereLoop *pWLoop;        /* One of the WhereLoop objects */
+  WhereLoop **pX;           /* Used to divy up the pSpace memory */
+  char *pSpace;             /* Temporary memory used by this routine */
+
+  pParse = pWInfo->pParse;
+  db = pParse->db;
+  nLoop = pWInfo->nLevel;
+  /* TUNING: For simple queries, only the best path is tracked.
+  ** For 2-way joins, the 5 best paths are followed.
+  ** For joins of 3 or more tables, track the 10 best paths */
+  mxChoice = (nLoop==1) ? 1 : (nLoop==2 ? 5 : 10);
+  assert( nLoop<=pWInfo->pTabList->nSrc );
+  WHERETRACE(0x002, ("---- begin solver\n"));
+
+  /* Allocate and initialize space for aTo and aFrom */
+  ii = (sizeof(WherePath)+sizeof(WhereLoop*)*nLoop)*mxChoice*2;
+  pSpace = sqlite3DbMallocRaw(db, ii);
+  if( pSpace==0 ) return SQLITE_NOMEM;
+  aTo = (WherePath*)pSpace;
+  aFrom = aTo+mxChoice;
+  memset(aFrom, 0, sizeof(aFrom[0]));
+  pX = (WhereLoop**)(aFrom+mxChoice);
+  for(ii=mxChoice*2, pFrom=aTo; ii>0; ii--, pFrom++, pX += nLoop){
+    pFrom->aLoop = pX;
+  }
+
+  /* Seed the search with a single WherePath containing zero WhereLoops.
+  **
+  ** TUNING: Do not let the number of iterations go above 25.  If the cost
+  ** of computing an automatic index is not paid back within the first 25
+  ** rows, then do not use the automatic index. */
+  aFrom[0].nRow = MIN(pParse->nQueryLoop, 46);  assert( 46==whereCost(25) );
+  nFrom = 1;
+
+  /* Precompute the cost of sorting the final result set, if the caller
+  ** to sqlite3WhereBegin() was concerned about sorting */
+  rSortCost = 0;
+  if( pWInfo->pOrderBy==0 || nRowEst==0 ){
+    aFrom[0].isOrderedValid = 1;
+  }else{
+    /* TUNING: Estimated cost of sorting is N*log2(N) where N is the
+    ** number of output rows. */
+    rSortCost = nRowEst + estLog(nRowEst);
+    WHERETRACE(0x002,("---- sort cost=%-3d\n", rSortCost));
+  }
+
+  /* Compute successively longer WherePaths using the previous generation
+  ** of WherePaths as the basis for the next.  Keep track of the mxChoice
+  ** best paths at each generation */
+  for(iLoop=0; iLoop<nLoop; iLoop++){
+    nTo = 0;
+    for(ii=0, pFrom=aFrom; ii<nFrom; ii++, pFrom++){
+      for(pWLoop=pWInfo->pLoops; pWLoop; pWLoop=pWLoop->pNextLoop){
+        Bitmask maskNew;
+        Bitmask revMask = 0;
+        u8 isOrderedValid = pFrom->isOrderedValid;
+        u8 isOrdered = pFrom->isOrdered;
+        if( (pWLoop->prereq & ~pFrom->maskLoop)!=0 ) continue;
+        if( (pWLoop->maskSelf & pFrom->maskLoop)!=0 ) continue;
+        /* At this point, pWLoop is a candidate to be the next loop. 
+        ** Compute its cost */
+        rCost = whereCostAdd(pWLoop->rSetup,pWLoop->rRun + pFrom->nRow);
+        rCost = whereCostAdd(rCost, pFrom->rCost);
+        maskNew = pFrom->maskLoop | pWLoop->maskSelf;
+        if( !isOrderedValid ){
+          switch( wherePathSatisfiesOrderBy(pWInfo,
+                       pWInfo->pOrderBy, pFrom, pWInfo->wctrlFlags,
+                       iLoop, pWLoop, &revMask) ){
+            case 1:  /* Yes.  pFrom+pWLoop does satisfy the ORDER BY clause */
+              isOrdered = 1;
+              isOrderedValid = 1;
+              break;
+            case 0:  /* No.  pFrom+pWLoop will require a separate sort */
+              isOrdered = 0;
+              isOrderedValid = 1;
+              rCost = whereCostAdd(rCost, rSortCost);
+              break;
+            default: /* Cannot tell yet.  Try again on the next iteration */
+              break;
+          }
+        }else{
+          revMask = pFrom->revLoop;
+        }
+        /* Check to see if pWLoop should be added to the mxChoice best so far */
+        for(jj=0, pTo=aTo; jj<nTo; jj++, pTo++){
+          if( pTo->maskLoop==maskNew && pTo->isOrderedValid==isOrderedValid ){
+            testcase( jj==nTo-1 );
+            break;
+          }
+        }
+        if( jj>=nTo ){
+          if( nTo>=mxChoice && rCost>=mxCost ){
+#ifdef WHERETRACE_ENABLED
+            if( sqlite3WhereTrace&0x4 ){
+              sqlite3DebugPrintf("Skip   %s cost=%3d order=%c\n",
+                  wherePathName(pFrom, iLoop, pWLoop), rCost,
+                  isOrderedValid ? (isOrdered ? 'Y' : 'N') : '?');
+            }
+#endif
+            continue;
+          }
+          /* Add a new Path to the aTo[] set */
+          if( nTo<mxChoice ){
+            /* Increase the size of the aTo set by one */
+            jj = nTo++;
+          }else{
+            /* New path replaces the prior worst to keep count below mxChoice */
+            for(jj=nTo-1; aTo[jj].rCost<mxCost; jj--){ assert(jj>0); }
+          }
+          pTo = &aTo[jj];
+#ifdef WHERETRACE_ENABLED
+          if( sqlite3WhereTrace&0x4 ){
+            sqlite3DebugPrintf("New    %s cost=%-3d order=%c\n",
+                wherePathName(pFrom, iLoop, pWLoop), rCost,
+                isOrderedValid ? (isOrdered ? 'Y' : 'N') : '?');
+          }
+#endif
+        }else{
+          if( pTo->rCost<=rCost ){
+#ifdef WHERETRACE_ENABLED
+            if( sqlite3WhereTrace&0x4 ){
+              sqlite3DebugPrintf(
+                  "Skip   %s cost=%-3d order=%c",
+                  wherePathName(pFrom, iLoop, pWLoop), rCost,
+                  isOrderedValid ? (isOrdered ? 'Y' : 'N') : '?');
+              sqlite3DebugPrintf("   vs %s cost=%-3d order=%c\n",
+                  wherePathName(pTo, iLoop+1, 0), pTo->rCost,
+                  pTo->isOrderedValid ? (pTo->isOrdered ? 'Y' : 'N') : '?');
+            }
+#endif
+            testcase( pTo->rCost==rCost );
+            continue;
+          }
+          testcase( pTo->rCost==rCost+1 );
+          /* A new and better score for a previously created equivalent path */
+#ifdef WHERETRACE_ENABLED
+          if( sqlite3WhereTrace&0x4 ){
+            sqlite3DebugPrintf(
+                "Update %s cost=%-3d order=%c",
+                wherePathName(pFrom, iLoop, pWLoop), rCost,
+                isOrderedValid ? (isOrdered ? 'Y' : 'N') : '?');
+            sqlite3DebugPrintf("  was %s cost=%-3d order=%c\n",
+                wherePathName(pTo, iLoop+1, 0), pTo->rCost,
+                pTo->isOrderedValid ? (pTo->isOrdered ? 'Y' : 'N') : '?');
+          }
+#endif
+        }
+        /* pWLoop is a winner.  Add it to the set of best so far */
+        pTo->maskLoop = pFrom->maskLoop | pWLoop->maskSelf;
+        pTo->revLoop = revMask;
+        pTo->nRow = pFrom->nRow + pWLoop->nOut;
+        pTo->rCost = rCost;
+        pTo->isOrderedValid = isOrderedValid;
+        pTo->isOrdered = isOrdered;
+        memcpy(pTo->aLoop, pFrom->aLoop, sizeof(WhereLoop*)*iLoop);
+        pTo->aLoop[iLoop] = pWLoop;
+        if( nTo>=mxChoice ){
+          mxCost = aTo[0].rCost;
+          for(jj=1, pTo=&aTo[1]; jj<mxChoice; jj++, pTo++){
+            if( pTo->rCost>mxCost ) mxCost = pTo->rCost;
+          }
+        }
+      }
+    }
+
+#ifdef WHERETRACE_ENABLED
+    if( sqlite3WhereTrace>=2 ){
+      sqlite3DebugPrintf("---- after round %d ----\n", iLoop);
+      for(ii=0, pTo=aTo; ii<nTo; ii++, pTo++){
+        sqlite3DebugPrintf(" %s cost=%-3d nrow=%-3d order=%c",
+           wherePathName(pTo, iLoop+1, 0), pTo->rCost, pTo->nRow,
+           pTo->isOrderedValid ? (pTo->isOrdered ? 'Y' : 'N') : '?');
+        if( pTo->isOrderedValid && pTo->isOrdered ){
+          sqlite3DebugPrintf(" rev=0x%llx\n", pTo->revLoop);
+        }else{
+          sqlite3DebugPrintf("\n");
+        }
+      }
+    }
+#endif
+
+    /* Swap the roles of aFrom and aTo for the next generation */
+    pFrom = aTo;
+    aTo = aFrom;
+    aFrom = pFrom;
+    nFrom = nTo;
+  }
+
+  if( nFrom==0 ){
+    sqlite3ErrorMsg(pParse, "no query solution");
+    sqlite3DbFree(db, pSpace);
+    return SQLITE_ERROR;
   }
+  
+  /* Find the lowest cost path.  pFrom will be left pointing to that path */
+  pFrom = aFrom;
+  assert( nFrom==1 );
+#if 0 /* The following is needed if nFrom is ever more than 1 */
+  for(ii=1; ii<nFrom; ii++){
+    if( pFrom->rCost>aFrom[ii].rCost ) pFrom = &aFrom[ii];
+  }
+#endif
+  assert( pWInfo->nLevel==nLoop );
+  /* Load the lowest cost path into pWInfo */
+  for(iLoop=0; iLoop<nLoop; iLoop++){
+    WhereLevel *pLevel = pWInfo->a + iLoop;
+    pLevel->pWLoop = pWLoop = pFrom->aLoop[iLoop];
+    pLevel->iFrom = pWLoop->iTab;
+    pLevel->iTabCur = pWInfo->pTabList->a[pLevel->iFrom].iCursor;
+  }
+  if( (pWInfo->wctrlFlags & WHERE_WANT_DISTINCT)!=0
+   && (pWInfo->wctrlFlags & WHERE_DISTINCTBY)==0
+   && pWInfo->eDistinct==WHERE_DISTINCT_NOOP
+   && nRowEst
+  ){
+    Bitmask notUsed;
+    int rc = wherePathSatisfiesOrderBy(pWInfo, pWInfo->pResultSet, pFrom,
+                 WHERE_DISTINCTBY, nLoop-1, pFrom->aLoop[nLoop-1], &notUsed);
+    if( rc==1 ) pWInfo->eDistinct = WHERE_DISTINCT_ORDERED;
+  }
+  if( pFrom->isOrdered ){
+    if( pWInfo->wctrlFlags & WHERE_DISTINCTBY ){
+      pWInfo->eDistinct = WHERE_DISTINCT_ORDERED;
+    }else{
+      pWInfo->bOBSat = 1;
+      pWInfo->revMask = pFrom->revLoop;
+    }
+  }
+  pWInfo->nRowOut = pFrom->nRow;
+
+  /* Free temporary memory and return success */
+  sqlite3DbFree(db, pSpace);
+  return SQLITE_OK;
 }
 
+/*
+** Most queries use only a single table (they are not joins) and have
+** simple == constraints against indexed fields.  This routine attempts
+** to plan those simple cases using much less ceremony than the
+** general-purpose query planner, and thereby yield faster sqlite3_prepare()
+** times for the common case.
+**
+** Return non-zero on success, if this query can be handled by this
+** no-frills query planner.  Return zero if this query needs the 
+** general-purpose query planner.
+*/
+static int whereShortCut(WhereLoopBuilder *pBuilder){
+  WhereInfo *pWInfo;
+  struct SrcList_item *pItem;
+  WhereClause *pWC;
+  WhereTerm *pTerm;
+  WhereLoop *pLoop;
+  int iCur;
+  int j;
+  Table *pTab;
+  Index *pIdx;
+  
+  pWInfo = pBuilder->pWInfo;
+  if( pWInfo->wctrlFlags & WHERE_FORCE_TABLE ) return 0;
+  assert( pWInfo->pTabList->nSrc>=1 );
+  pItem = pWInfo->pTabList->a;
+  pTab = pItem->pTab;
+  if( IsVirtual(pTab) ) return 0;
+  if( pItem->zIndex ) return 0;
+  iCur = pItem->iCursor;
+  pWC = &pWInfo->sWC;
+  pLoop = pBuilder->pNew;
+  pLoop->wsFlags = 0;
+  pTerm = findTerm(pWC, iCur, -1, 0, WO_EQ, 0);
+  if( pTerm ){
+    pLoop->wsFlags = WHERE_COLUMN_EQ|WHERE_IPK|WHERE_ONEROW;
+    pLoop->aLTerm[0] = pTerm;
+    pLoop->nLTerm = 1;
+    pLoop->u.btree.nEq = 1;
+    /* TUNING: Cost of a rowid lookup is 10 */
+    pLoop->rRun = 33;  /* 33==whereCost(10) */
+  }else{
+    for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){
+      assert( pLoop->aLTermSpace==pLoop->aLTerm );
+      assert( ArraySize(pLoop->aLTermSpace)==4 );
+      if( pIdx->onError==OE_None 
+       || pIdx->pPartIdxWhere!=0 
+       || pIdx->nColumn>ArraySize(pLoop->aLTermSpace) 
+      ) continue;
+      for(j=0; j<pIdx->nColumn; j++){
+        pTerm = findTerm(pWC, iCur, pIdx->aiColumn[j], 0, WO_EQ, pIdx);
+        if( pTerm==0 ) break;
+        pLoop->aLTerm[j] = pTerm;
+      }
+      if( j!=pIdx->nColumn ) continue;
+      pLoop->wsFlags = WHERE_COLUMN_EQ|WHERE_ONEROW|WHERE_INDEXED;
+      if( (pItem->colUsed & ~columnsInIndex(pIdx))==0 ){
+        pLoop->wsFlags |= WHERE_IDX_ONLY;
+      }
+      pLoop->nLTerm = j;
+      pLoop->u.btree.nEq = j;
+      pLoop->u.btree.pIndex = pIdx;
+      /* TUNING: Cost of a unique index lookup is 15 */
+      pLoop->rRun = 39;  /* 39==whereCost(15) */
+      break;
+    }
+  }
+  if( pLoop->wsFlags ){
+    pLoop->nOut = (WhereCost)1;
+    pWInfo->a[0].pWLoop = pLoop;
+    pLoop->maskSelf = getMask(&pWInfo->sMaskSet, iCur);
+    pWInfo->a[0].iTabCur = iCur;
+    pWInfo->nRowOut = 1;
+    if( pWInfo->pOrderBy ) pWInfo->bOBSat =  1;
+    if( pWInfo->wctrlFlags & WHERE_WANT_DISTINCT ){
+      pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
+    }
+#ifdef SQLITE_DEBUG
+    pLoop->cId = '0';
+#endif
+    return 1;
+  }
+  return 0;
+}
 
 /*
 ** Generate the beginning of the loop used for WHERE clause processing.
@@ -5037,25 +5668,17 @@ static void whereInfoFree(sqlite3 *db, WhereInfo *pWInfo){
 **
 ** ORDER BY CLAUSE PROCESSING
 **
-** pOrderBy is a pointer to the ORDER BY clause of a SELECT statement,
+** pOrderBy is a pointer to the ORDER BY clause (or the GROUP BY clause
+** if the WHERE_GROUPBY flag is set in wctrlFlags) of a SELECT statement
 ** if there is one.  If there is no ORDER BY clause or if this routine
 ** is called from an UPDATE or DELETE statement, then pOrderBy is NULL.
-**
-** If an index can be used so that the natural output order of the table
-** scan is correct for the ORDER BY clause, then that index is used and
-** the returned WhereInfo.nOBSat field is set to pOrderBy->nExpr.  This
-** is an optimization that prevents an unnecessary sort of the result set
-** if an index appropriate for the ORDER BY clause already exists.
-**
-** If the where clause loops cannot be arranged to provide the correct
-** output order, then WhereInfo.nOBSat is 0.
 */
 WhereInfo *sqlite3WhereBegin(
   Parse *pParse,        /* The parser context */
-  SrcList *pTabList,    /* A list of all tables to be scanned */
+  SrcList *pTabList,    /* FROM clause: A list of all tables to be scanned */
   Expr *pWhere,         /* The WHERE clause */
   ExprList *pOrderBy,   /* An ORDER BY clause, or NULL */
-  ExprList *pDistinct,  /* The select-list for DISTINCT queries - or NULL */
+  ExprList *pResultSet, /* Result set of the query */
   u16 wctrlFlags,       /* One of the WHERE_* flags defined in sqliteInt.h */
   int iIdxCur           /* If WHERE_ONETABLE_ONLY is set, index cursor number */
 ){
@@ -5064,18 +5687,25 @@ WhereInfo *sqlite3WhereBegin(
   WhereInfo *pWInfo;         /* Will become the return value of this function */
   Vdbe *v = pParse->pVdbe;   /* The virtual database engine */
   Bitmask notReady;          /* Cursors that are not yet positioned */
-  WhereBestIdx sWBI;         /* Best index search context */
+  WhereLoopBuilder sWLB;     /* The WhereLoop builder */
   WhereMaskSet *pMaskSet;    /* The expression mask set */
   WhereLevel *pLevel;        /* A single level in pWInfo->a[] */
-  int iFrom;                 /* First unused FROM clause element */
-  int andFlags;              /* AND-ed combination of all pWC->a[].wtFlags */
+  WhereLoop *pLoop;          /* Pointer to a single WhereLoop object */
   int ii;                    /* Loop counter */
   sqlite3 *db;               /* Database connection */
+  int rc;                    /* Return code */
 
 
   /* Variable initialization */
-  memset(&sWBI, 0, sizeof(sWBI));
-  sWBI.pParse = pParse;
+  db = pParse->db;
+  memset(&sWLB, 0, sizeof(sWLB));
+  sWLB.pOrderBy = pOrderBy;
+
+  /* Disable the DISTINCT optimization if SQLITE_DistinctOpt is set via
+  ** sqlite3_test_ctrl(SQLITE_TESTCTRL_OPTIMIZATIONS,...) */
+  if( OptimizationDisabled(db, SQLITE_DistinctOpt) ){
+    wctrlFlags &= ~WHERE_WANT_DISTINCT;
+  }
 
   /* The number of tables in the FROM clause is limited by the number of
   ** bits in a Bitmask 
@@ -5100,13 +5730,8 @@ WhereInfo *sqlite3WhereBegin(
   ** field (type Bitmask) it must be aligned on an 8-byte boundary on
   ** some architectures. Hence the ROUND8() below.
   */
-  db = pParse->db;
   nByteWInfo = ROUND8(sizeof(WhereInfo)+(nTabList-1)*sizeof(WhereLevel));
-  pWInfo = sqlite3DbMallocZero(db, 
-      nByteWInfo + 
-      sizeof(WhereClause) +
-      sizeof(WhereMaskSet)
-  );
+  pWInfo = sqlite3DbMallocZero(db, nByteWInfo + sizeof(WhereLoop));
   if( db->mallocFailed ){
     sqlite3DbFree(db, pWInfo);
     pWInfo = 0;
@@ -5115,24 +5740,29 @@ WhereInfo *sqlite3WhereBegin(
   pWInfo->nLevel = nTabList;
   pWInfo->pParse = pParse;
   pWInfo->pTabList = pTabList;
+  pWInfo->pOrderBy = pOrderBy;
+  pWInfo->pResultSet = pResultSet;
   pWInfo->iBreak = sqlite3VdbeMakeLabel(v);
-  pWInfo->pWC = sWBI.pWC = (WhereClause *)&((u8 *)pWInfo)[nByteWInfo];
   pWInfo->wctrlFlags = wctrlFlags;
   pWInfo->savedNQueryLoop = pParse->nQueryLoop;
-  pMaskSet = (WhereMaskSet*)&sWBI.pWC[1];
-  sWBI.aLevel = pWInfo->a;
-
-  /* Disable the DISTINCT optimization if SQLITE_DistinctOpt is set via
-  ** sqlite3_test_ctrl(SQLITE_TESTCTRL_OPTIMIZATIONS,...) */
-  if( OptimizationDisabled(db, SQLITE_DistinctOpt) ) pDistinct = 0;
+  pMaskSet = &pWInfo->sMaskSet;
+  sWLB.pWInfo = pWInfo;
+  sWLB.pWC = &pWInfo->sWC;
+  sWLB.pNew = (WhereLoop*)(((char*)pWInfo)+nByteWInfo);
+  assert( EIGHT_BYTE_ALIGNMENT(sWLB.pNew) );
+  whereLoopInit(sWLB.pNew);
+#ifdef SQLITE_DEBUG
+  sWLB.pNew->cId = '*';
+#endif
 
   /* Split the WHERE clause into separate subexpressions where each
   ** subexpression is separated by an AND operator.
   */
   initMaskSet(pMaskSet);
-  whereClauseInit(sWBI.pWC, pParse, pMaskSet, wctrlFlags);
+  whereClauseInit(&pWInfo->sWC, pWInfo);
   sqlite3ExprCodeConstants(pParse, pWhere);
-  whereSplit(sWBI.pWC, pWhere, TK_AND);   /* IMP: R-15842-53296 */
+  whereSplit(&pWInfo->sWC, pWhere, TK_AND);
+  sqlite3CodeVerifySchema(pParse, -1); /* Insert the cookie verifier Goto */
     
   /* Special case: a WHERE clause that is constant.  Evaluate the
   ** expression and either jump over all of the code or fall thru.
@@ -5142,6 +5772,15 @@ WhereInfo *sqlite3WhereBegin(
     pWhere = 0;
   }
 
+  /* Special case: No FROM clause
+  */
+  if( nTabList==0 ){
+    if( pOrderBy ) pWInfo->bOBSat = 1;
+    if( wctrlFlags & WHERE_WANT_DISTINCT ){
+      pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
+    }
+  }
+
   /* Assign a bit from the bitmask to every term in the FROM clause.
   **
   ** When assigning bitmask values to FROM clause cursors, it must be
@@ -5177,288 +5816,131 @@ WhereInfo *sqlite3WhereBegin(
   ** want to analyze these virtual terms, so start analyzing at the end
   ** and work forward so that the added virtual terms are never processed.
   */
-  exprAnalyzeAll(pTabList, sWBI.pWC);
+  exprAnalyzeAll(pTabList, &pWInfo->sWC);
   if( db->mallocFailed ){
     goto whereBeginError;
   }
 
-  /* Check if the DISTINCT qualifier, if there is one, is redundant. 
-  ** If it is, then set pDistinct to NULL and WhereInfo.eDistinct to
-  ** WHERE_DISTINCT_UNIQUE to tell the caller to ignore the DISTINCT.
+  /* If the ORDER BY (or GROUP BY) clause contains references to general
+  ** expressions, then we won't be able to satisfy it using indices, so
+  ** go ahead and disable it now.
   */
-  if( pDistinct && isDistinctRedundant(pParse, pTabList, sWBI.pWC, pDistinct) ){
-    pDistinct = 0;
-    pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
+  if( pOrderBy && (wctrlFlags & WHERE_WANT_DISTINCT)!=0 ){
+    for(ii=0; ii<pOrderBy->nExpr; ii++){
+      Expr *pExpr = sqlite3ExprSkipCollate(pOrderBy->a[ii].pExpr);
+      if( pExpr->op!=TK_COLUMN ){
+        pWInfo->pOrderBy = pOrderBy = 0;
+        break;
+      }else if( pExpr->iColumn<0 ){
+        break;
+      }
+    }
   }
 
-  /* Chose the best index to use for each table in the FROM clause.
-  **
-  ** This loop fills in the following fields:
-  **
-  **   pWInfo->a[].pIdx      The index to use for this level of the loop.
-  **   pWInfo->a[].wsFlags   WHERE_xxx flags associated with pIdx
-  **   pWInfo->a[].nEq       The number of == and IN constraints
-  **   pWInfo->a[].iFrom     Which term of the FROM clause is being coded
-  **   pWInfo->a[].iTabCur   The VDBE cursor for the database table
-  **   pWInfo->a[].iIdxCur   The VDBE cursor for the index
-  **   pWInfo->a[].pTerm     When wsFlags==WO_OR, the OR-clause term
-  **
-  ** This loop also figures out the nesting order of tables in the FROM
-  ** clause.
-  */
-  sWBI.notValid = ~(Bitmask)0;
-  sWBI.pOrderBy = pOrderBy;
-  sWBI.n = nTabList;
-  sWBI.pDistinct = pDistinct;
-  andFlags = ~0;
-  WHERETRACE(("*** Optimizer Start ***\n"));
-  for(sWBI.i=iFrom=0, pLevel=pWInfo->a; sWBI.i<nTabList; sWBI.i++, pLevel++){
-    WhereCost bestPlan;         /* Most efficient plan seen so far */
-    Index *pIdx;                /* Index for FROM table at pTabItem */
-    int j;                      /* For looping over FROM tables */
-    int bestJ = -1;             /* The value of j */
-    Bitmask m;                  /* Bitmask value for j or bestJ */
-    int isOptimal;              /* Iterator for optimal/non-optimal search */
-    int ckOptimal;              /* Do the optimal scan check */
-    int nUnconstrained;         /* Number tables without INDEXED BY */
-    Bitmask notIndexed;         /* Mask of tables that cannot use an index */
-
-    memset(&bestPlan, 0, sizeof(bestPlan));
-    bestPlan.rCost = SQLITE_BIG_DBL;
-    WHERETRACE(("*** Begin search for loop %d ***\n", sWBI.i));
-
-    /* Loop through the remaining entries in the FROM clause to find the
-    ** next nested loop. The loop tests all FROM clause entries
-    ** either once or twice. 
-    **
-    ** The first test is always performed if there are two or more entries
-    ** remaining and never performed if there is only one FROM clause entry
-    ** to choose from.  The first test looks for an "optimal" scan.  In
-    ** this context an optimal scan is one that uses the same strategy
-    ** for the given FROM clause entry as would be selected if the entry
-    ** were used as the innermost nested loop.  In other words, a table
-    ** is chosen such that the cost of running that table cannot be reduced
-    ** by waiting for other tables to run first.  This "optimal" test works
-    ** by first assuming that the FROM clause is on the inner loop and finding
-    ** its query plan, then checking to see if that query plan uses any
-    ** other FROM clause terms that are sWBI.notValid.  If no notValid terms
-    ** are used then the "optimal" query plan works.
-    **
-    ** Note that the WhereCost.nRow parameter for an optimal scan might
-    ** not be as small as it would be if the table really were the innermost
-    ** join.  The nRow value can be reduced by WHERE clause constraints
-    ** that do not use indices.  But this nRow reduction only happens if the
-    ** table really is the innermost join.  
-    **
-    ** The second loop iteration is only performed if no optimal scan
-    ** strategies were found by the first iteration. This second iteration
-    ** is used to search for the lowest cost scan overall.
-    **
-    ** Without the optimal scan step (the first iteration) a suboptimal
-    ** plan might be chosen for queries like this:
-    **   
-    **   CREATE TABLE t1(a, b); 
-    **   CREATE TABLE t2(c, d);
-    **   SELECT * FROM t2, t1 WHERE t2.rowid = t1.a;
-    **
-    ** The best strategy is to iterate through table t1 first. However it
-    ** is not possible to determine this with a simple greedy algorithm.
-    ** Since the cost of a linear scan through table t2 is the same 
-    ** as the cost of a linear scan through table t1, a simple greedy 
-    ** algorithm may choose to use t2 for the outer loop, which is a much
-    ** costlier approach.
-    */
-    nUnconstrained = 0;
-    notIndexed = 0;
-
-    /* The optimal scan check only occurs if there are two or more tables
-    ** available to be reordered */
-    if( iFrom==nTabList-1 ){
-      ckOptimal = 0;  /* Common case of just one table in the FROM clause */
-    }else{
-      ckOptimal = -1;
-      for(j=iFrom, sWBI.pSrc=&pTabList->a[j]; j<nTabList; j++, sWBI.pSrc++){
-        m = getMask(pMaskSet, sWBI.pSrc->iCursor);
-        if( (m & sWBI.notValid)==0 ){
-          if( j==iFrom ) iFrom++;
-          continue;
-        }
-        if( j>iFrom && (sWBI.pSrc->jointype & (JT_LEFT|JT_CROSS))!=0 ) break;
-        if( ++ckOptimal ) break;
-        if( (sWBI.pSrc->jointype & JT_LEFT)!=0 ) break;
-      }
+  if( wctrlFlags & WHERE_WANT_DISTINCT ){
+    if( isDistinctRedundant(pParse, pTabList, &pWInfo->sWC, pResultSet) ){
+      /* The DISTINCT marking is pointless.  Ignore it. */
+      pWInfo->eDistinct = WHERE_DISTINCT_UNIQUE;
+    }else if( pOrderBy==0 ){
+      /* Try to ORDER BY the result set to make distinct processing easier */
+      pWInfo->wctrlFlags |= WHERE_DISTINCTBY;
+      pWInfo->pOrderBy = pResultSet;
     }
-    assert( ckOptimal==0 || ckOptimal==1 );
+  }
 
-    for(isOptimal=ckOptimal; isOptimal>=0 && bestJ<0; isOptimal--){
-      for(j=iFrom, sWBI.pSrc=&pTabList->a[j]; j<nTabList; j++, sWBI.pSrc++){
-        if( j>iFrom && (sWBI.pSrc->jointype & (JT_LEFT|JT_CROSS))!=0 ){
-          /* This break and one like it in the ckOptimal computation loop
-          ** above prevent table reordering across LEFT and CROSS JOINs.
-          ** The LEFT JOIN case is necessary for correctness.  The prohibition
-          ** against reordering across a CROSS JOIN is an SQLite feature that
-          ** allows the developer to control table reordering */
-          break;
-        }
-        m = getMask(pMaskSet, sWBI.pSrc->iCursor);
-        if( (m & sWBI.notValid)==0 ){
-          assert( j>iFrom );
-          continue;
-        }
-        sWBI.notReady = (isOptimal ? m : sWBI.notValid);
-        if( sWBI.pSrc->pIndex==0 ) nUnconstrained++;
+  /* Construct the WhereLoop objects */
+  WHERETRACE(0xffff,("*** Optimizer Start ***\n"));
+  if( nTabList!=1 || whereShortCut(&sWLB)==0 ){
+    rc = whereLoopAddAll(&sWLB);
+    if( rc ) goto whereBeginError;
   
-        WHERETRACE(("   === trying table %d (%s) with isOptimal=%d ===\n",
-                    j, sWBI.pSrc->pTab->zName, isOptimal));
-        assert( sWBI.pSrc->pTab );
-#ifndef SQLITE_OMIT_VIRTUALTABLE
-        if( IsVirtual(sWBI.pSrc->pTab) ){
-          sWBI.ppIdxInfo = &pWInfo->a[j].pIdxInfo;
-          bestVirtualIndex(&sWBI);
-        }else 
-#endif
-        {
-          bestBtreeIndex(&sWBI);
-        }
-        assert( isOptimal || (sWBI.cost.used&sWBI.notValid)==0 );
-
-        /* If an INDEXED BY clause is present, then the plan must use that
-        ** index if it uses any index at all */
-        assert( sWBI.pSrc->pIndex==0 
-                  || (sWBI.cost.plan.wsFlags & WHERE_NOT_FULLSCAN)==0
-                  || sWBI.cost.plan.u.pIdx==sWBI.pSrc->pIndex );
-
-        if( isOptimal && (sWBI.cost.plan.wsFlags & WHERE_NOT_FULLSCAN)==0 ){
-          notIndexed |= m;
-        }
-        if( isOptimal ){
-          pWInfo->a[j].rOptCost = sWBI.cost.rCost;
-        }else if( ckOptimal ){
-          /* If two or more tables have nearly the same outer loop cost, but
-          ** very different inner loop (optimal) cost, we want to choose
-          ** for the outer loop that table which benefits the least from
-          ** being in the inner loop.  The following code scales the 
-          ** outer loop cost estimate to accomplish that. */
-          WHERETRACE(("   scaling cost from %.1f to %.1f\n",
-                      sWBI.cost.rCost,
-                      sWBI.cost.rCost/pWInfo->a[j].rOptCost));
-          sWBI.cost.rCost /= pWInfo->a[j].rOptCost;
-        }
-
-        /* Conditions under which this table becomes the best so far:
-        **
-        **   (1) The table must not depend on other tables that have not
-        **       yet run.  (In other words, it must not depend on tables
-        **       in inner loops.)
-        **
-        **   (2) (This rule was removed on 2012-11-09.  The scaling of the
-        **       cost using the optimal scan cost made this rule obsolete.)
-        **
-        **   (3) All tables have an INDEXED BY clause or this table lacks an
-        **       INDEXED BY clause or this table uses the specific
-        **       index specified by its INDEXED BY clause.  This rule ensures
-        **       that a best-so-far is always selected even if an impossible
-        **       combination of INDEXED BY clauses are given.  The error
-        **       will be detected and relayed back to the application later.
-        **       The NEVER() comes about because rule (2) above prevents
-        **       An indexable full-table-scan from reaching rule (3).
-        **
-        **   (4) The plan cost must be lower than prior plans, where "cost"
-        **       is defined by the compareCost() function above. 
-        */
-        if( (sWBI.cost.used&sWBI.notValid)==0                    /* (1) */
-            && (nUnconstrained==0 || sWBI.pSrc->pIndex==0        /* (3) */
-                || NEVER((sWBI.cost.plan.wsFlags & WHERE_NOT_FULLSCAN)!=0))
-            && (bestJ<0 || compareCost(&sWBI.cost, &bestPlan))   /* (4) */
-        ){
-          WHERETRACE(("   === table %d (%s) is best so far\n"
-                      "       cost=%.1f, nRow=%.1f, nOBSat=%d, wsFlags=%08x\n",
-                      j, sWBI.pSrc->pTab->zName,
-                      sWBI.cost.rCost, sWBI.cost.plan.nRow,
-                      sWBI.cost.plan.nOBSat, sWBI.cost.plan.wsFlags));
-          bestPlan = sWBI.cost;
-          bestJ = j;
-        }
-
-        /* In a join like "w JOIN x LEFT JOIN y JOIN z"  make sure that
-        ** table y (and not table z) is always the next inner loop inside
-        ** of table x. */
-        if( (sWBI.pSrc->jointype & JT_LEFT)!=0 ) break;
+    /* Display all of the WhereLoop objects if wheretrace is enabled */
+#ifdef WHERETRACE_ENABLED
+    if( sqlite3WhereTrace ){
+      WhereLoop *p;
+      int i;
+      static char zLabel[] = "0123456789abcdefghijklmnopqrstuvwyxz"
+                                       "ABCDEFGHIJKLMNOPQRSTUVWYXZ";
+      for(p=pWInfo->pLoops, i=0; p; p=p->pNextLoop, i++){
+        p->cId = zLabel[i%sizeof(zLabel)];
+        whereLoopPrint(p, pTabList);
       }
     }
-    assert( bestJ>=0 );
-    assert( sWBI.notValid & getMask(pMaskSet, pTabList->a[bestJ].iCursor) );
-    assert( bestJ==iFrom || (pTabList->a[iFrom].jointype & JT_LEFT)==0 );
-    testcase( bestJ>iFrom && (pTabList->a[iFrom].jointype & JT_CROSS)!=0 );
-    testcase( bestJ>iFrom && bestJ<nTabList-1
-                          && (pTabList->a[bestJ+1].jointype & JT_LEFT)!=0 );
-    WHERETRACE(("*** Optimizer selects table %d (%s) for loop %d with:\n"
-                "    cost=%.1f, nRow=%.1f, nOBSat=%d, wsFlags=0x%08x\n",
-                bestJ, pTabList->a[bestJ].pTab->zName,
-                pLevel-pWInfo->a, bestPlan.rCost, bestPlan.plan.nRow,
-                bestPlan.plan.nOBSat, bestPlan.plan.wsFlags));
-    if( (bestPlan.plan.wsFlags & WHERE_DISTINCT)!=0 ){
-      assert( pWInfo->eDistinct==0 );
-      pWInfo->eDistinct = WHERE_DISTINCT_ORDERED;
+#endif
+  
+    wherePathSolver(pWInfo, 0);
+    if( db->mallocFailed ) goto whereBeginError;
+    if( pWInfo->pOrderBy ){
+       wherePathSolver(pWInfo, pWInfo->nRowOut+1);
+       if( db->mallocFailed ) goto whereBeginError;
     }
-    andFlags &= bestPlan.plan.wsFlags;
-    pLevel->plan = bestPlan.plan;
-    pLevel->iTabCur = pTabList->a[bestJ].iCursor;
-    testcase( bestPlan.plan.wsFlags & WHERE_INDEXED );
-    testcase( bestPlan.plan.wsFlags & WHERE_TEMP_INDEX );
-    if( bestPlan.plan.wsFlags & (WHERE_INDEXED|WHERE_TEMP_INDEX) ){
-      if( (wctrlFlags & WHERE_ONETABLE_ONLY) 
-       && (bestPlan.plan.wsFlags & WHERE_TEMP_INDEX)==0 
-      ){
-        pLevel->iIdxCur = iIdxCur;
-      }else{
-        pLevel->iIdxCur = pParse->nTab++;
+  }
+  if( pWInfo->pOrderBy==0 && (db->flags & SQLITE_ReverseOrder)!=0 ){
+     pWInfo->revMask = (Bitmask)(-1);
+  }
+  if( pParse->nErr || NEVER(db->mallocFailed) ){
+    goto whereBeginError;
+  }
+#ifdef WHERETRACE_ENABLED
+  if( sqlite3WhereTrace ){
+    int ii;
+    sqlite3DebugPrintf("---- Solution nRow=%d", pWInfo->nRowOut);
+    if( pWInfo->bOBSat ){
+      sqlite3DebugPrintf(" ORDERBY=0x%llx", pWInfo->revMask);
+    }
+    switch( pWInfo->eDistinct ){
+      case WHERE_DISTINCT_UNIQUE: {
+        sqlite3DebugPrintf("  DISTINCT=unique");
+        break;
+      }
+      case WHERE_DISTINCT_ORDERED: {
+        sqlite3DebugPrintf("  DISTINCT=ordered");
+        break;
+      }
+      case WHERE_DISTINCT_UNORDERED: {
+        sqlite3DebugPrintf("  DISTINCT=unordered");
+        break;
       }
-    }else{
-      pLevel->iIdxCur = -1;
     }
-    sWBI.notValid &= ~getMask(pMaskSet, pTabList->a[bestJ].iCursor);
-    pLevel->iFrom = (u8)bestJ;
-    if( bestPlan.plan.nRow>=(double)1 ){
-      pParse->nQueryLoop *= bestPlan.plan.nRow;
+    sqlite3DebugPrintf("\n");
+    for(ii=0; ii<pWInfo->nLevel; ii++){
+      whereLoopPrint(pWInfo->a[ii].pWLoop, pTabList);
     }
-
-    /* Check that if the table scanned by this loop iteration had an
-    ** INDEXED BY clause attached to it, that the named index is being
-    ** used for the scan. If not, then query compilation has failed.
-    ** Return an error.
-    */
-    pIdx = pTabList->a[bestJ].pIndex;
-    if( pIdx ){
-      if( (bestPlan.plan.wsFlags & WHERE_INDEXED)==0 ){
-        sqlite3ErrorMsg(pParse, "cannot use index: %s", pIdx->zName);
-        goto whereBeginError;
-      }else{
-        /* If an INDEXED BY clause is used, the bestIndex() function is
-        ** guaranteed to find the index specified in the INDEXED BY clause
-        ** if it find an index at all. */
-        assert( bestPlan.plan.u.pIdx==pIdx );
+  }
+#endif
+  /* Attempt to omit tables from the join that do not effect the result */
+  if( pWInfo->nLevel>=2
+   && pResultSet!=0
+   && OptimizationEnabled(db, SQLITE_OmitNoopJoin)
+  ){
+    Bitmask tabUsed = exprListTableUsage(pMaskSet, pResultSet);
+    if( sWLB.pOrderBy ) tabUsed |= exprListTableUsage(pMaskSet, sWLB.pOrderBy);
+    while( pWInfo->nLevel>=2 ){
+      WhereTerm *pTerm, *pEnd;
+      pLoop = pWInfo->a[pWInfo->nLevel-1].pWLoop;
+      if( (pWInfo->pTabList->a[pLoop->iTab].jointype & JT_LEFT)==0 ) break;
+      if( (wctrlFlags & WHERE_WANT_DISTINCT)==0
+       && (pLoop->wsFlags & WHERE_ONEROW)==0
+      ){
+        break;
+      }
+      if( (tabUsed & pLoop->maskSelf)!=0 ) break;
+      pEnd = sWLB.pWC->a + sWLB.pWC->nTerm;
+      for(pTerm=sWLB.pWC->a; pTerm<pEnd; pTerm++){
+        if( (pTerm->prereqAll & pLoop->maskSelf)!=0
+         && !ExprHasProperty(pTerm->pExpr, EP_FromJoin)
+        ){
+          break;
+        }
       }
+      if( pTerm<pEnd ) break;
+      WHERETRACE(0xffff, ("-> drop loop %c not used\n", pLoop->cId));
+      pWInfo->nLevel--;
+      nTabList--;
     }
   }
-  WHERETRACE(("*** Optimizer Finished ***\n"));
-  if( pParse->nErr || db->mallocFailed ){
-    goto whereBeginError;
-  }
-  if( nTabList ){
-    pLevel--;
-    pWInfo->nOBSat = pLevel->plan.nOBSat;
-  }else{
-    pWInfo->nOBSat = 0;
-  }
-
-  /* If the total query only selects a single row, then the ORDER BY
-  ** clause is irrelevant.
-  */
-  if( (andFlags & WHERE_UNIQUE)!=0 && pOrderBy ){
-    assert( nTabList==0 || (pLevel->plan.wsFlags & WHERE_ALL_UNIQUE)!=0 );
-    pWInfo->nOBSat = pOrderBy->nExpr;
-  }
+  WHERETRACE(0xffff,("*** Optimizer Finished ***\n"));
+  pWInfo->pParse->nQueryLoop += pWInfo->nRowOut;
 
   /* If the caller is an UPDATE or DELETE statement that is requesting
   ** to use a one-pass algorithm, determine if this is appropriate.
@@ -5466,17 +5948,16 @@ WhereInfo *sqlite3WhereBegin(
   ** the statement to update a single row.
   */
   assert( (wctrlFlags & WHERE_ONEPASS_DESIRED)==0 || pWInfo->nLevel==1 );
-  if( (wctrlFlags & WHERE_ONEPASS_DESIRED)!=0 && (andFlags & WHERE_UNIQUE)!=0 ){
+  if( (wctrlFlags & WHERE_ONEPASS_DESIRED)!=0 
+   && (pWInfo->a[0].pWLoop->wsFlags & WHERE_ONEROW)!=0 ){
     pWInfo->okOnePass = 1;
-    pWInfo->a[0].plan.wsFlags &= ~WHERE_IDX_ONLY;
+    pWInfo->a[0].pWLoop->wsFlags &= ~WHERE_IDX_ONLY;
   }
 
   /* Open all tables in the pTabList and any indices selected for
   ** searching those tables.
   */
-  sqlite3CodeVerifySchema(pParse, -1); /* Insert the cookie verifier Goto */
   notReady = ~(Bitmask)0;
-  pWInfo->nRowOut = (double)1;
   for(ii=0, pLevel=pWInfo->a; ii<nTabList; ii++, pLevel++){
     Table *pTab;     /* Table to open */
     int iDb;         /* Index of database containing table/index */
@@ -5484,13 +5965,13 @@ WhereInfo *sqlite3WhereBegin(
 
     pTabItem = &pTabList->a[pLevel->iFrom];
     pTab = pTabItem->pTab;
-    pWInfo->nRowOut *= pLevel->plan.nRow;
     iDb = sqlite3SchemaToIndex(db, pTab->pSchema);
+    pLoop = pLevel->pWLoop;
     if( (pTab->tabFlags & TF_Ephemeral)!=0 || pTab->pSelect ){
       /* Do nothing */
     }else
 #ifndef SQLITE_OMIT_VIRTUALTABLE
-    if( (pLevel->plan.wsFlags & WHERE_VIRTUALTABLE)!=0 ){
+    if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)!=0 ){
       const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);
       int iCur = pTabItem->iCursor;
       sqlite3VdbeAddOp4(v, OP_VOpen, iCur, 0, 0, pVTab, P4_VTAB);
@@ -5498,12 +5979,12 @@ WhereInfo *sqlite3WhereBegin(
       /* noop */
     }else
 #endif
-    if( (pLevel->plan.wsFlags & WHERE_IDX_ONLY)==0
+    if( (pLoop->wsFlags & WHERE_IDX_ONLY)==0
          && (wctrlFlags & WHERE_OMIT_OPEN_CLOSE)==0 ){
       int op = pWInfo->okOnePass ? OP_OpenWrite : OP_OpenRead;
       sqlite3OpenTable(pParse, pTabItem->iCursor, iDb, pTab, op);
-      testcase( pTab->nCol==BMS-1 );
-      testcase( pTab->nCol==BMS );
+      testcase( !pWInfo->okOnePass && pTab->nCol==BMS-1 );
+      testcase( !pWInfo->okOnePass && pTab->nCol==BMS );
       if( !pWInfo->okOnePass && pTab->nCol<BMS ){
         Bitmask b = pTabItem->colUsed;
         int n = 0;
@@ -5515,15 +5996,11 @@ WhereInfo *sqlite3WhereBegin(
     }else{
       sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName);
     }
-#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
-    if( (pLevel->plan.wsFlags & WHERE_TEMP_INDEX)!=0 ){
-      constructAutomaticIndex(pParse, sWBI.pWC, pTabItem, notReady, pLevel);
-    }else
-#endif
-    if( (pLevel->plan.wsFlags & WHERE_INDEXED)!=0 ){
-      Index *pIx = pLevel->plan.u.pIdx;
+    if( pLoop->wsFlags & WHERE_INDEXED ){
+      Index *pIx = pLoop->u.btree.pIndex;
       KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIx);
-      int iIndexCur = pLevel->iIdxCur;
+      /* FIXME:  As an optimization use pTabItem->iCursor if WHERE_IDX_ONLY */
+      int iIndexCur = pLevel->iIdxCur = iIdxCur ? iIdxCur : pParse->nTab++;
       assert( pIx->pSchema==pTab->pSchema );
       assert( iIndexCur>=0 );
       sqlite3VdbeAddOp4(v, OP_OpenRead, iIndexCur, pIx->tnum, iDb,
@@ -5531,7 +6008,7 @@ WhereInfo *sqlite3WhereBegin(
       VdbeComment((v, "%s", pIx->zName));
     }
     sqlite3CodeVerifySchema(pParse, iDb);
-    notReady &= ~getMask(sWBI.pWC->pMaskSet, pTabItem->iCursor);
+    notReady &= ~getMask(&pWInfo->sMaskSet, pTabItem->iCursor);
   }
   pWInfo->iTop = sqlite3VdbeCurrentAddr(v);
   if( db->mallocFailed ) goto whereBeginError;
@@ -5543,67 +6020,20 @@ WhereInfo *sqlite3WhereBegin(
   notReady = ~(Bitmask)0;
   for(ii=0; ii<nTabList; ii++){
     pLevel = &pWInfo->a[ii];
+#ifndef SQLITE_OMIT_AUTOMATIC_INDEX
+    if( (pLevel->pWLoop->wsFlags & WHERE_AUTO_INDEX)!=0 ){
+      constructAutomaticIndex(pParse, &pWInfo->sWC,
+                &pTabList->a[pLevel->iFrom], notReady, pLevel);
+      if( db->mallocFailed ) goto whereBeginError;
+    }
+#endif
     explainOneScan(pParse, pTabList, pLevel, ii, pLevel->iFrom, wctrlFlags);
-    notReady = codeOneLoopStart(pWInfo, ii, wctrlFlags, notReady);
+    pLevel->addrBody = sqlite3VdbeCurrentAddr(v);
+    notReady = codeOneLoopStart(pWInfo, ii, notReady);
     pWInfo->iContinue = pLevel->addrCont;
   }
 
-#ifdef SQLITE_TEST  /* For testing and debugging use only */
-  /* Record in the query plan information about the current table
-  ** and the index used to access it (if any).  If the table itself
-  ** is not used, its name is just '{}'.  If no index is used
-  ** the index is listed as "{}".  If the primary key is used the
-  ** index name is '*'.
-  */
-  for(ii=0; ii<nTabList; ii++){
-    char *z;
-    int n;
-    int w;
-    struct SrcList_item *pTabItem;
-
-    pLevel = &pWInfo->a[ii];
-    w = pLevel->plan.wsFlags;
-    pTabItem = &pTabList->a[pLevel->iFrom];
-    z = pTabItem->zAlias;
-    if( z==0 ) z = pTabItem->pTab->zName;
-    n = sqlite3Strlen30(z);
-    if( n+nQPlan < sizeof(sqlite3_query_plan)-10 ){
-      if( (w & WHERE_IDX_ONLY)!=0 && (w & WHERE_COVER_SCAN)==0 ){
-        memcpy(&sqlite3_query_plan[nQPlan], "{}", 2);
-        nQPlan += 2;
-      }else{
-        memcpy(&sqlite3_query_plan[nQPlan], z, n);
-        nQPlan += n;
-      }
-      sqlite3_query_plan[nQPlan++] = ' ';
-    }
-    testcase( w & WHERE_ROWID_EQ );
-    testcase( w & WHERE_ROWID_RANGE );
-    if( w & (WHERE_ROWID_EQ|WHERE_ROWID_RANGE) ){
-      memcpy(&sqlite3_query_plan[nQPlan], "* ", 2);
-      nQPlan += 2;
-    }else if( (w & WHERE_INDEXED)!=0 && (w & WHERE_COVER_SCAN)==0 ){
-      n = sqlite3Strlen30(pLevel->plan.u.pIdx->zName);
-      if( n+nQPlan < sizeof(sqlite3_query_plan)-2 ){
-        memcpy(&sqlite3_query_plan[nQPlan], pLevel->plan.u.pIdx->zName, n);
-        nQPlan += n;
-        sqlite3_query_plan[nQPlan++] = ' ';
-      }
-    }else{
-      memcpy(&sqlite3_query_plan[nQPlan], "{} ", 3);
-      nQPlan += 3;
-    }
-  }
-  while( nQPlan>0 && sqlite3_query_plan[nQPlan-1]==' ' ){
-    sqlite3_query_plan[--nQPlan] = 0;
-  }
-  sqlite3_query_plan[nQPlan] = 0;
-  nQPlan = 0;
-#endif /* SQLITE_TEST // Testing and debugging use only */
-
-  /* Record the continuation address in the WhereInfo structure.  Then
-  ** clean up and return.
-  */
+  /* Done. */
   return pWInfo;
 
   /* Jump here if malloc fails */
@@ -5624,6 +6054,7 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
   Vdbe *v = pParse->pVdbe;
   int i;
   WhereLevel *pLevel;
+  WhereLoop *pLoop;
   SrcList *pTabList = pWInfo->pTabList;
   sqlite3 *db = pParse->db;
 
@@ -5632,12 +6063,13 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
   sqlite3ExprCacheClear(pParse);
   for(i=pWInfo->nLevel-1; i>=0; i--){
     pLevel = &pWInfo->a[i];
+    pLoop = pLevel->pWLoop;
     sqlite3VdbeResolveLabel(v, pLevel->addrCont);
     if( pLevel->op!=OP_Noop ){
       sqlite3VdbeAddOp2(v, pLevel->op, pLevel->p1, pLevel->p2);
       sqlite3VdbeChangeP5(v, pLevel->p5);
     }
-    if( pLevel->plan.wsFlags & WHERE_IN_ABLE && pLevel->u.in.nIn>0 ){
+    if( pLoop->wsFlags & WHERE_IN_ABLE && pLevel->u.in.nIn>0 ){
       struct InLoop *pIn;
       int j;
       sqlite3VdbeResolveLabel(v, pLevel->addrNxt);
@@ -5652,12 +6084,12 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
     if( pLevel->iLeftJoin ){
       int addr;
       addr = sqlite3VdbeAddOp1(v, OP_IfPos, pLevel->iLeftJoin);
-      assert( (pLevel->plan.wsFlags & WHERE_IDX_ONLY)==0
-           || (pLevel->plan.wsFlags & WHERE_INDEXED)!=0 );
-      if( (pLevel->plan.wsFlags & WHERE_IDX_ONLY)==0 ){
+      assert( (pLoop->wsFlags & WHERE_IDX_ONLY)==0
+           || (pLoop->wsFlags & WHERE_INDEXED)!=0 );
+      if( (pLoop->wsFlags & WHERE_IDX_ONLY)==0 ){
         sqlite3VdbeAddOp1(v, OP_NullRow, pTabList->a[i].iCursor);
       }
-      if( pLevel->iIdxCur>=0 ){
+      if( pLoop->wsFlags & WHERE_INDEXED ){
         sqlite3VdbeAddOp1(v, OP_NullRow, pLevel->iIdxCur);
       }
       if( pLevel->op==OP_Return ){
@@ -5676,31 +6108,30 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
 
   /* Close all of the cursors that were opened by sqlite3WhereBegin.
   */
-  assert( pWInfo->nLevel==1 || pWInfo->nLevel==pTabList->nSrc );
+  assert( pWInfo->nLevel<=pTabList->nSrc );
   for(i=0, pLevel=pWInfo->a; i<pWInfo->nLevel; i++, pLevel++){
     Index *pIdx = 0;
     struct SrcList_item *pTabItem = &pTabList->a[pLevel->iFrom];
     Table *pTab = pTabItem->pTab;
     assert( pTab!=0 );
+    pLoop = pLevel->pWLoop;
     if( (pTab->tabFlags & TF_Ephemeral)==0
      && pTab->pSelect==0
      && (pWInfo->wctrlFlags & WHERE_OMIT_OPEN_CLOSE)==0
     ){
-      int ws = pLevel->plan.wsFlags;
+      int ws = pLoop->wsFlags;
       if( !pWInfo->okOnePass && (ws & WHERE_IDX_ONLY)==0 ){
         sqlite3VdbeAddOp1(v, OP_Close, pTabItem->iCursor);
       }
-      if( (ws & WHERE_INDEXED)!=0 && (ws & WHERE_TEMP_INDEX)==0 ){
+      if( (ws & WHERE_INDEXED)!=0 && (ws & (WHERE_IPK|WHERE_AUTO_INDEX))==0 ){
         sqlite3VdbeAddOp1(v, OP_Close, pLevel->iIdxCur);
       }
     }
 
-    /* If this scan uses an index, make code substitutions to read data
-    ** from the index in preference to the table. Sometimes, this means
-    ** the table need never be read from. This is a performance boost,
-    ** as the vdbe level waits until the table is read before actually
-    ** seeking the table cursor to the record corresponding to the current
-    ** position in the index.
+    /* If this scan uses an index, make VDBE code substitutions to read data
+    ** from the index instead of from the table where possible.  In some cases
+    ** this optimization prevents the table from ever being read, which can
+    ** yield a significant performance boost.
     ** 
     ** Calls to the code generator in between sqlite3WhereBegin and
     ** sqlite3WhereEnd will have created code that references the table
@@ -5708,18 +6139,19 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
     ** that reference the table and converts them into opcodes that
     ** reference the index.
     */
-    if( pLevel->plan.wsFlags & WHERE_INDEXED ){
-      pIdx = pLevel->plan.u.pIdx;
-    }else if( pLevel->plan.wsFlags & WHERE_MULTI_OR ){
+    if( pLoop->wsFlags & (WHERE_INDEXED|WHERE_IDX_ONLY) ){
+      pIdx = pLoop->u.btree.pIndex;
+    }else if( pLoop->wsFlags & WHERE_MULTI_OR ){
       pIdx = pLevel->u.pCovidx;
     }
-    if( pIdx && !db->mallocFailed){
+    if( pIdx && !db->mallocFailed ){
       int k, j, last;
       VdbeOp *pOp;
 
-      pOp = sqlite3VdbeGetOp(v, pWInfo->iTop);
       last = sqlite3VdbeCurrentAddr(v);
-      for(k=pWInfo->iTop; k<last; k++, pOp++){
+      k = pLevel->addrBody;
+      pOp = sqlite3VdbeGetOp(v, k);
+      for(; k<last; k++, pOp++){
         if( pOp->p1!=pLevel->iTabCur ) continue;
         if( pOp->opcode==OP_Column ){
           for(j=0; j<pIdx->nColumn; j++){
@@ -5729,8 +6161,7 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
               break;
             }
           }
-          assert( (pLevel->plan.wsFlags & WHERE_IDX_ONLY)==0
-               || j<pIdx->nColumn );
+          assert( (pLoop->wsFlags & WHERE_IDX_ONLY)==0 || j<pIdx->nColumn );
         }else if( pOp->opcode==OP_Rowid ){
           pOp->p1 = pLevel->iIdxCur;
           pOp->opcode = OP_IdxRowid;
diff --git a/lib/libsqlite3/tool/build-all-msvc.bat b/lib/libsqlite3/tool/build-all-msvc.bat
index 758036fb757..c4334357793 100755
--- a/lib/libsqlite3/tool/build-all-msvc.bat
+++ b/lib/libsqlite3/tool/build-all-msvc.bat
@@ -374,7 +374,7 @@ FOR %%P IN (%PLATFORMS%) DO (
           REM       need to remove the build output for the files we are
           REM       specifically wanting to build for each platform.
           REM
-          %__ECHO% DEL /Q sqlite3.dll sqlite3.lib sqlite3.pdb
+          %__ECHO% DEL /Q *.lo sqlite3.dll sqlite3.lib sqlite3.pdb
         )
 
         REM
diff --git a/lib/libsqlite3/tool/mkautoconfamal.sh b/lib/libsqlite3/tool/mkautoconfamal.sh
new file mode 100644
index 00000000000..c13f7c999ad
--- /dev/null
+++ b/lib/libsqlite3/tool/mkautoconfamal.sh
@@ -0,0 +1,83 @@
+#!/bin/sh
+# This script is used to build the amalgamation autoconf package.
+# It assumes the following:
+#
+#   1. The files "sqlite3.c", "sqlite3.h" and "sqlite3ext.h"
+#      are available in the current directory.
+#
+#   2. Variable $TOP is set to the full path of the root directory
+#      of the SQLite source tree.
+#
+#   3. There is nothing of value in the ./mkpkg_tmp_dir directory.
+#      This is important, as the script executes "rm -rf ./mkpkg_tmp_dir".
+#
+
+
+# Bail out of the script if any command returns a non-zero exit 
+# status. Or if the script tries to use an unset variable. These
+# may fail for old /bin/sh interpreters.
+#
+set -e
+set -u
+
+TMPSPACE=./mkpkg_tmp_dir
+VERSION=`cat $TOP/VERSION`
+
+# Set global variable $ARTIFACT to the "3xxyyzz" string incorporated 
+# into artifact filenames. And $VERSION2 to the "3.x.y[.z]" form.
+xx=`echo $VERSION|sed 's/3\.\([0-9]*\)\..*/\1/'`
+yy=`echo $VERSION|sed 's/3\.[^.]*\.\([0-9]*\).*/\1/'`
+zz=0
+set +e
+  zz=`echo $VERSION|sed 's/3\.[^.]*\.[^.]*\.\([0-9]*\).*/\1/'|grep -v '\.'`
+set -e
+ARTIFACT=`printf "3%.2d%.2d%.2d" $xx $yy $zz`
+
+rm -rf $TMPSPACE
+cp -R $TOP/autoconf $TMPSPACE
+
+cp sqlite3.c          $TMPSPACE
+cp sqlite3.h          $TMPSPACE
+cp sqlite3ext.h       $TMPSPACE
+cp $TOP/sqlite3.1     $TMPSPACE
+cp $TOP/sqlite3.pc.in $TMPSPACE
+cp $TOP/src/shell.c   $TMPSPACE
+
+chmod 755 $TMPSPACE/install-sh
+chmod 755 $TMPSPACE/missing
+chmod 755 $TMPSPACE/depcomp
+chmod 755 $TMPSPACE/config.sub
+chmod 755 $TMPSPACE/config.guess
+
+cat $TMPSPACE/configure.ac |
+sed "s/AC_INIT(sqlite, .*, http:\/\/www.sqlite.org)/AC_INIT(sqlite, $VERSION, http:\/\/www.sqlite.org)/" > $TMPSPACE/tmp
+mv $TMPSPACE/tmp $TMPSPACE/configure.ac
+
+cd $TMPSPACE
+aclocal
+autoconf
+automake
+
+mkdir -p tea/generic
+echo "#ifdef USE_SYSTEM_SQLITE"      > tea/generic/tclsqlite3.c 
+echo "# include <sqlite3.h>"        >> tea/generic/tclsqlite3.c
+echo "#else"                        >> tea/generic/tclsqlite3.c
+echo "#include \"../../sqlite3.c\"" >> tea/generic/tclsqlite3.c
+echo "#endif"                       >> tea/generic/tclsqlite3.c
+cat  $TOP/src/tclsqlite.c           >> tea/generic/tclsqlite3.c
+
+cat tea/configure.in | 
+  sed "s/AC_INIT(\[sqlite\], .*)/AC_INIT([sqlite], [$VERSION])/" > tmp
+mv tmp tea/configure.in
+
+cd tea
+autoconf
+rm -rf autom4te.cache
+
+cd ../
+./configure && make dist
+tar -xzf sqlite-$VERSION.tar.gz
+mv sqlite-$VERSION sqlite-autoconf-$ARTIFACT
+tar -czf sqlite-autoconf-$ARTIFACT.tar.gz sqlite-autoconf-$ARTIFACT
+mv sqlite-autoconf-$ARTIFACT.tar.gz ..
+
diff --git a/lib/libsqlite3/tool/spaceanal.tcl b/lib/libsqlite3/tool/spaceanal.tcl
index 6988f6e8b93..e2f23fe4bf2 100644
--- a/lib/libsqlite3/tool/spaceanal.tcl
+++ b/lib/libsqlite3/tool/spaceanal.tcl
@@ -246,8 +246,19 @@ mem function int integerify
 # [quote {hello world's}] == {'hello world''s'}
 #
 proc quote {txt} {
-  regsub -all ' $txt '' q
-  return '$q'
+  return [string map {' ''} $txt]
+}
+
+# Output a title line
+#
+proc titleline {title} {
+  if {$title==""} {
+    puts [string repeat * 79]
+  } else {
+    set len [string length $title]
+    set stars [string repeat * [expr 79-$len-5]]
+    puts "*** $title $stars"
+  }
 }
 
 # Generate a single line of output in the statistics section of the
@@ -255,7 +266,7 @@ proc quote {txt} {
 #
 proc statline {title value {extra {}}} {
   set len [string length $title]
-  set dots [string range {......................................} $len end]
+  set dots [string repeat . [expr 50-$len]]
   set len [string length $value]
   set sp2 [string range {          } $len end]
   if {$extra ne ""} {
@@ -319,9 +330,7 @@ proc subreport {title where} {
   # Output the sub-report title, nicely decorated with * characters.
   #
   puts ""
-  set len [string length $title]
-  set stars [string repeat * [expr 65-$len]]
-  puts "*** $title $stars"
+  titleline $title
   puts ""
 
   # Calculate statistics and store the results in TCL variables, as follows:
@@ -490,9 +499,6 @@ set user_percent [percent $user_payload $file_bytes]
 # Output the summary statistics calculated above.
 #
 puts "/** Disk-Space Utilization Report For $root_filename"
-catch {
-  puts "*** As of [clock format [clock seconds] -format {%Y-%b-%d %H:%M:%S}]"
-}
 puts ""
 statline {Page size in bytes} $pageSize
 statline {Pages in the whole file (measured)} $file_pgcnt
@@ -517,16 +523,27 @@ statline {Bytes of user payload stored} $user_payload $user_percent
 # Output table rankings
 #
 puts ""
-puts "*** Page counts for all tables with their indices ********************"
+titleline "Page counts for all tables with their indices"
 puts ""
 mem eval {SELECT tblname, count(*) AS cnt, 
               int(sum(int_pages+leaf_pages+ovfl_pages)) AS size
           FROM space_used GROUP BY tblname ORDER BY size+0 DESC, tblname} {} {
   statline [string toupper $tblname] $size [percent $size $file_pgcnt]
 }
+puts ""
+titleline "Page counts for all tables and indices separately"
+puts ""
+mem eval {
+  SELECT
+       upper(name) AS nm,
+       int(int_pages+leaf_pages+ovfl_pages) AS size
+    FROM space_used
+   ORDER BY size+0 DESC, name} {} {
+  statline $nm $size [percent $size $file_pgcnt]
+}
 if {$isCompressed} {
   puts ""
-  puts "*** Bytes of disk space used after compression ***********************"
+  titleline "Bytes of disk space used after compression"
   puts ""
   set csum 0
   mem eval {SELECT tblname,
@@ -554,13 +571,22 @@ if {$nindex>0} {
 }
 foreach tbl [mem eval {SELECT name FROM space_used WHERE NOT is_index
                        ORDER BY name}] {
-  regsub ' $tbl '' qn
+  set qn [quote $tbl]
   set name [string toupper $tbl]
-  set n [mem eval "SELECT count(*) FROM space_used WHERE tblname='$qn'"]
+  set n [mem eval {SELECT count(*) FROM space_used WHERE tblname=$tbl}]
   if {$n>1} {
+    set idxlist [mem eval "SELECT name FROM space_used
+                            WHERE tblname='$qn' AND is_index
+                            ORDER BY 1"]
     subreport "Table $name and all its indices" "tblname='$qn'"
     subreport "Table $name w/o any indices" "name='$qn'"
-    subreport "Indices of table $name" "tblname='$qn' AND is_index"
+    if {[llength $idxlist]>1} {
+      subreport "Indices of table $name" "tblname='$qn' AND is_index"
+    }
+    foreach idx $idxlist {
+      set qidx [quote $idx]
+      subreport "Index [string toupper $idx] of table $name" "name='$qidx'"
+    }
   } else {
     subreport "Table $name" "name='$qn'"
   }
@@ -568,9 +594,9 @@ foreach tbl [mem eval {SELECT name FROM space_used WHERE NOT is_index
 
 # Output instructions on what the numbers above mean.
 #
+puts ""
+titleline Definitions
 puts {
-*** Definitions ******************************************************
-
 Page size in bytes
 
     The number of bytes in a single page of the database file.  
@@ -722,7 +748,7 @@ Unused bytes on all pages
 # Output a dump of the in-memory database. This can be used for more
 # complex offline analysis.
 #
-puts "**********************************************************************"
+titleline {}
 puts "The entire text of this report can be sourced into any SQL database"
 puts "engine for further analysis.  All of the text above is an SQL comment."
 puts "The data used to generate this report follows:"
diff --git a/lib/libsqlite3/tool/wherecosttest.c b/lib/libsqlite3/tool/wherecosttest.c
new file mode 100644
index 00000000000..39d4a7a3682
--- /dev/null
+++ b/lib/libsqlite3/tool/wherecosttest.c
@@ -0,0 +1,111 @@
+/*
+** 2013-06-10
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+** This file contains a simple command-line utility for converting from
+** integers and WhereCost values and back again and for doing simple
+** arithmetic operations (multiple and add) on WhereCost values.
+**
+** Usage:
+**
+**      ./wherecosttest ARGS
+**
+** Arguments:
+**
+**    'x'    Multiple the top two elements of the stack
+**    '+'    Add the top two elements of the stack
+**    NUM    Convert NUM from integer to WhereCost and push onto the stack
+**   ^NUM    Interpret NUM as a WhereCost and push onto stack.
+**
+** Examples:
+**
+** To convert 123 from WhereCost to integer:
+** 
+**         ./wherecosttest ^123
+**
+** To convert 123456 from integer to WhereCost:
+**
+**         ./wherecosttest 123456
+**
+*/
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+
+typedef unsigned short int WhereCost;  /* 10 times log2() */
+
+WhereCost whereCostMultiply(WhereCost a, WhereCost b){ return a+b; }
+WhereCost whereCostAdd(WhereCost a, WhereCost b){
+  static const unsigned char x[] = {
+     10, 10,                         /* 0,1 */
+      9, 9,                          /* 2,3 */
+      8, 8,                          /* 4,5 */
+      7, 7, 7,                       /* 6,7,8 */
+      6, 6, 6,                       /* 9,10,11 */
+      5, 5, 5,                       /* 12-14 */
+      4, 4, 4, 4,                    /* 15-18 */
+      3, 3, 3, 3, 3, 3,              /* 19-24 */
+      2, 2, 2, 2, 2, 2, 2,           /* 25-31 */
+  };
+  if( a<b ){ WhereCost t = a; a = b; b = t; }
+  if( a>b+49 ) return a;
+  if( a>b+31 ) return a+1;
+  return a+x[a-b];
+}
+WhereCost whereCostFromInteger(int x){
+  static WhereCost a[] = { 0, 2, 3, 5, 6, 7, 8, 9 };
+  WhereCost y = 40;
+  if( x<8 ){
+    if( x<2 ) return 0;
+    while( x<8 ){  y -= 10; x <<= 1; }
+  }else{
+    while( x>255 ){ y += 40; x >>= 4; }
+    while( x>15 ){  y += 10; x >>= 1; }
+  }
+  return a[x&7] + y - 10;
+}
+static unsigned long int whereCostToInt(WhereCost x){
+  unsigned long int n;
+  if( x<10 ) return 1;
+  n = x%10;
+  x /= 10;
+  if( n>=5 ) n -= 2;
+  else if( n>=1 ) n -= 1;
+  if( x>=3 ) return (n+8)<<(x-3);
+  return (n+8)>>(3-x);
+}
+
+int main(int argc, char **argv){
+  int i;
+  int n = 0;
+  WhereCost a[100];
+  for(i=1; i<argc; i++){
+    const char *z = argv[i];
+    if( z[0]=='+' ){
+      if( n>=2 ){
+        a[n-2] = whereCostAdd(a[n-2],a[n-1]);
+        n--;
+      }
+    }else if( z[0]=='x' ){
+      if( n>=2 ){
+        a[n-2] = whereCostMultiply(a[n-2],a[n-1]);
+        n--;
+      }
+    }else if( z[0]=='^' ){
+      a[n++] = atoi(z+1);
+    }else{
+      a[n++] = whereCostFromInteger(atoi(z));
+    }
+  }
+  for(i=n-1; i>=0; i--){
+    printf("%d (%lu)\n", a[i], whereCostToInt(a[i]));
+  }
+  return 0;
+}
author	jturner <jturner@openbsd.org>	2013-09-21 17:29:17 +0000
committer	jturner <jturner@openbsd.org>	2013-09-21 17:29:17 +0000
commit	97d5d4b962418e3e648246a809ce03d33b566903 (patch)
tree	328321c85977b8756ec8d84f6d12e16569cb3fa4 /lib/libsqlite3
parent	regen (diff)
download	wireguard-openbsd-97d5d4b962418e3e648246a809ce03d33b566903.tar.xz wireguard-openbsd-97d5d4b962418e3e648246a809ce03d33b566903.zip