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Diffstat (limited to 'lib/libsqlite3/src/analyze.c')
| -rw-r--r-- | lib/libsqlite3/src/analyze.c | 1891 |
1 files changed, 0 insertions, 1891 deletions
diff --git a/lib/libsqlite3/src/analyze.c b/lib/libsqlite3/src/analyze.c deleted file mode 100644 index ad752d2c0e7..00000000000 --- a/lib/libsqlite3/src/analyze.c +++ /dev/null @@ -1,1891 +0,0 @@ -/* -** 2005-07-08 -** -** 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 associated with the ANALYZE command. -** -** The ANALYZE command gather statistics about the content of tables -** and indices. These statistics are made available to the query planner -** to help it make better decisions about how to perform queries. -** -** The following system tables are or have been supported: -** -** CREATE TABLE sqlite_stat1(tbl, idx, stat); -** CREATE TABLE sqlite_stat2(tbl, idx, sampleno, sample); -** CREATE TABLE sqlite_stat3(tbl, idx, nEq, nLt, nDLt, sample); -** CREATE TABLE sqlite_stat4(tbl, idx, nEq, nLt, nDLt, sample); -** -** Additional tables might be added in future releases of SQLite. -** 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 -** The sqlite_stat2 table is superseded by sqlite_stat3, which is only -** created and used by SQLite versions 3.7.9 and later and with -** SQLITE_ENABLE_STAT3 defined.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 functionality of sqlite_stat3 -** is a superset of sqlite_stat2. The sqlite_stat4 is an enhanced -** version of sqlite_stat3 and is only available when compiled with -** SQLITE_ENABLE_STAT4 and in SQLite versions 3.8.1 and later. It is -** not possible to enable both STAT3 and STAT4 at the same time. If they -** are both enabled, then STAT4 takes precedence. -** -** For most applications, sqlite_stat1 provides all the statistics required -** for the query planner to make good choices. -** -** Format of sqlite_stat1: -** -** There is normally one row per index, with the index identified by the -** name in the idx column. The tbl column is the name of the table to -** which the index belongs. In each such row, the stat column will be -** a string consisting of a list of integers. The first integer in this -** list is the number of rows in the index. (This is the same as the -** number of rows in the table, except for partial indices.) The second -** integer is the average number of rows in the index that have the same -** value in the first column of the index. The third integer is the average -** number of rows in the index that have the same value for the first two -** columns. The N-th integer (for N>1) is the average number of rows in -** the index which have the same value for the first N-1 columns. For -** a K-column index, there will be K+1 integers in the stat column. If -** the index is unique, then the last integer will be 1. -** -** The list of integers in the stat column can optionally be followed -** by the keyword "unordered". The "unordered" keyword, if it is present, -** must be separated from the last integer by a single space. If the -** "unordered" keyword is present, then the query planner assumes that -** the index is unordered and will not use the index for a range query. -** -** If the sqlite_stat1.idx column is NULL, then the sqlite_stat1.stat -** column contains a single integer which is the (estimated) number of -** rows in the table identified by sqlite_stat1.tbl. -** -** Format of sqlite_stat2: -** -** The sqlite_stat2 is only created and is only used if SQLite is compiled -** with SQLITE_ENABLE_STAT2 and if the SQLite version number is between -** 3.6.18 and 3.7.8. The "stat2" table contains additional information -** about the distribution of keys within an index. The index is identified by -** the "idx" column and the "tbl" column is the name of the table to which -** the index belongs. There are usually 10 rows in the sqlite_stat2 -** table for each index. -** -** The sqlite_stat2 entries for an index that have sampleno between 0 and 9 -** inclusive are samples of the left-most key value in the index taken at -** evenly spaced points along the index. Let the number of samples be S -** (10 in the standard build) and let C be the number of rows in the index. -** Then the sampled rows are given by: -** -** rownumber = (i*C*2 + C)/(S*2) -** -** For i between 0 and S-1. Conceptually, the index space is divided into -** S uniform buckets and the samples are the middle row from each bucket. -** -** The format for sqlite_stat2 is recorded here for legacy reference. This -** version of SQLite does not support sqlite_stat2. It neither reads nor -** writes the sqlite_stat2 table. This version of SQLite only supports -** sqlite_stat3. -** -** Format for sqlite_stat3: -** -** The sqlite_stat3 format is a subset of sqlite_stat4. Hence, the -** sqlite_stat4 format will be described first. Further information -** about sqlite_stat3 follows the sqlite_stat4 description. -** -** Format for sqlite_stat4: -** -** As with sqlite_stat2, the sqlite_stat4 table contains histogram data -** to aid the query planner in choosing good indices based on the values -** that indexed columns are compared against in the WHERE clauses of -** queries. -** -** The sqlite_stat4 table contains multiple entries for each index. -** The idx column names the index and the tbl column is the table of the -** index. If the idx and tbl columns are the same, then the sample is -** of the INTEGER PRIMARY KEY. The sample column is a blob which is the -** binary encoding of a key from the index. The nEq column is a -** list of integers. The first integer is the approximate number -** of entries in the index whose left-most column exactly matches -** the left-most column of the sample. The second integer in nEq -** is the approximate number of entries in the index where the -** first two columns match the first two columns of the sample. -** And so forth. nLt is another list of integers that show the approximate -** number of entries that are strictly less than the sample. The first -** integer in nLt contains the number of entries in the index where the -** left-most column is less than the left-most column of the sample. -** The K-th integer in the nLt entry is the number of index entries -** where the first K columns are less than the first K columns of the -** sample. The nDLt column is like nLt except that it contains the -** number of distinct entries in the index that are less than the -** sample. -** -** There can be an arbitrary number of sqlite_stat4 entries per index. -** The ANALYZE command will typically generate sqlite_stat4 tables -** that contain between 10 and 40 samples which are distributed across -** the key space, though not uniformly, and which include samples with -** large nEq values. -** -** Format for sqlite_stat3 redux: -** -** The sqlite_stat3 table is like sqlite_stat4 except that it only -** looks at the left-most column of the index. The sqlite_stat3.sample -** column contains the actual value of the left-most column instead -** of a blob encoding of the complete index key as is found in -** sqlite_stat4.sample. The nEq, nLt, and nDLt entries of sqlite_stat3 -** all contain just a single integer which is the same as the first -** integer in the equivalent columns in sqlite_stat4. -*/ -#ifndef SQLITE_OMIT_ANALYZE -#include "sqliteInt.h" - -#if defined(SQLITE_ENABLE_STAT4) -# define IsStat4 1 -# define IsStat3 0 -#elif defined(SQLITE_ENABLE_STAT3) -# define IsStat4 0 -# define IsStat3 1 -#else -# define IsStat4 0 -# define IsStat3 0 -# undef SQLITE_STAT4_SAMPLES -# define SQLITE_STAT4_SAMPLES 1 -#endif -#define IsStat34 (IsStat3+IsStat4) /* 1 for STAT3 or STAT4. 0 otherwise */ - -/* -** This routine generates code that opens the sqlite_statN tables. -** The sqlite_stat1 table is always relevant. sqlite_stat2 is now -** obsolete. sqlite_stat3 and sqlite_stat4 are only opened when -** appropriate compile-time options are provided. -** -** If the sqlite_statN tables do not previously exist, it is created. -** -** Argument zWhere may be a pointer to a buffer containing a table name, -** or it may be a NULL pointer. If it is not NULL, then all entries in -** the sqlite_statN tables associated with the named table are deleted. -** If zWhere==0, then code is generated to delete all stat table entries. -*/ -static void openStatTable( - Parse *pParse, /* Parsing context */ - int iDb, /* The database we are looking in */ - int iStatCur, /* Open the sqlite_stat1 table on this cursor */ - const char *zWhere, /* Delete entries for this table or index */ - const char *zWhereType /* Either "tbl" or "idx" */ -){ - static const struct { - const char *zName; - const char *zCols; - } aTable[] = { - { "sqlite_stat1", "tbl,idx,stat" }, -#if defined(SQLITE_ENABLE_STAT4) - { "sqlite_stat4", "tbl,idx,neq,nlt,ndlt,sample" }, - { "sqlite_stat3", 0 }, -#elif defined(SQLITE_ENABLE_STAT3) - { "sqlite_stat3", "tbl,idx,neq,nlt,ndlt,sample" }, - { "sqlite_stat4", 0 }, -#else - { "sqlite_stat3", 0 }, - { "sqlite_stat4", 0 }, -#endif - }; - int i; - sqlite3 *db = pParse->db; - Db *pDb; - Vdbe *v = sqlite3GetVdbe(pParse); - int aRoot[ArraySize(aTable)]; - u8 aCreateTbl[ArraySize(aTable)]; - - if( v==0 ) return; - assert( sqlite3BtreeHoldsAllMutexes(db) ); - assert( sqlite3VdbeDb(v)==db ); - pDb = &db->aDb[iDb]; - - /* Create new statistic tables if they do not exist, or clear them - ** if they do already exist. - */ - for(i=0; i<ArraySize(aTable); i++){ - const char *zTab = aTable[i].zName; - Table *pStat; - if( (pStat = sqlite3FindTable(db, zTab, pDb->zName))==0 ){ - if( aTable[i].zCols ){ - /* The sqlite_statN table does not exist. Create it. Note that a - ** side-effect of the CREATE TABLE statement is to leave the rootpage - ** of the new table in register pParse->regRoot. This is important - ** because the OpenWrite opcode below will be needing it. */ - sqlite3NestedParse(pParse, - "CREATE TABLE %Q.%s(%s)", pDb->zName, zTab, aTable[i].zCols - ); - aRoot[i] = pParse->regRoot; - aCreateTbl[i] = OPFLAG_P2ISREG; - } - }else{ - /* The table already exists. If zWhere is not NULL, delete all entries - ** associated with the table zWhere. If zWhere is NULL, delete the - ** entire contents of the table. */ - aRoot[i] = pStat->tnum; - aCreateTbl[i] = 0; - sqlite3TableLock(pParse, iDb, aRoot[i], 1, zTab); - if( zWhere ){ - sqlite3NestedParse(pParse, - "DELETE FROM %Q.%s WHERE %s=%Q", - pDb->zName, zTab, zWhereType, zWhere - ); - }else{ - /* The sqlite_stat[134] table already exists. Delete all rows. */ - sqlite3VdbeAddOp2(v, OP_Clear, aRoot[i], iDb); - } - } - } - - /* Open the sqlite_stat[134] tables for writing. */ - for(i=0; aTable[i].zCols; i++){ - assert( i<ArraySize(aTable) ); - sqlite3VdbeAddOp4Int(v, OP_OpenWrite, iStatCur+i, aRoot[i], iDb, 3); - sqlite3VdbeChangeP5(v, aCreateTbl[i]); - VdbeComment((v, aTable[i].zName)); - } -} - -/* -** Recommended number of samples for sqlite_stat4 -*/ -#ifndef SQLITE_STAT4_SAMPLES -# define SQLITE_STAT4_SAMPLES 24 -#endif - -/* -** Three SQL functions - stat_init(), stat_push(), and stat_get() - -** share an instance of the following structure to hold their state -** information. -*/ -typedef struct Stat4Accum Stat4Accum; -typedef struct Stat4Sample Stat4Sample; -struct Stat4Sample { - tRowcnt *anEq; /* sqlite_stat4.nEq */ - tRowcnt *anDLt; /* sqlite_stat4.nDLt */ -#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 - tRowcnt *anLt; /* sqlite_stat4.nLt */ - union { - i64 iRowid; /* Rowid in main table of the key */ - u8 *aRowid; /* Key for WITHOUT ROWID tables */ - } u; - u32 nRowid; /* Sizeof aRowid[] */ - u8 isPSample; /* True if a periodic sample */ - int iCol; /* If !isPSample, the reason for inclusion */ - u32 iHash; /* Tiebreaker hash */ -#endif -}; -struct Stat4Accum { - tRowcnt nRow; /* Number of rows in the entire table */ - tRowcnt nPSample; /* How often to do a periodic sample */ - int nCol; /* Number of columns in index + pk/rowid */ - int nKeyCol; /* Number of index columns w/o the pk/rowid */ - int mxSample; /* Maximum number of samples to accumulate */ - Stat4Sample current; /* Current row as a Stat4Sample */ - u32 iPrn; /* Pseudo-random number used for sampling */ - Stat4Sample *aBest; /* Array of nCol best samples */ - int iMin; /* Index in a[] of entry with minimum score */ - int nSample; /* Current number of samples */ - int iGet; /* Index of current sample accessed by stat_get() */ - Stat4Sample *a; /* Array of mxSample Stat4Sample objects */ - sqlite3 *db; /* Database connection, for malloc() */ -}; - -/* Reclaim memory used by a Stat4Sample -*/ -#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 -static void sampleClear(sqlite3 *db, Stat4Sample *p){ - assert( db!=0 ); - if( p->nRowid ){ - sqlite3DbFree(db, p->u.aRowid); - p->nRowid = 0; - } -} -#endif - -/* Initialize the BLOB value of a ROWID -*/ -#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 -static void sampleSetRowid(sqlite3 *db, Stat4Sample *p, int n, const u8 *pData){ - assert( db!=0 ); - if( p->nRowid ) sqlite3DbFree(db, p->u.aRowid); - p->u.aRowid = sqlite3DbMallocRaw(db, n); - if( p->u.aRowid ){ - p->nRowid = n; - memcpy(p->u.aRowid, pData, n); - }else{ - p->nRowid = 0; - } -} -#endif - -/* Initialize the INTEGER value of a ROWID. -*/ -#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 -static void sampleSetRowidInt64(sqlite3 *db, Stat4Sample *p, i64 iRowid){ - assert( db!=0 ); - if( p->nRowid ) sqlite3DbFree(db, p->u.aRowid); - p->nRowid = 0; - p->u.iRowid = iRowid; -} -#endif - - -/* -** Copy the contents of object (*pFrom) into (*pTo). -*/ -#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 -static void sampleCopy(Stat4Accum *p, Stat4Sample *pTo, Stat4Sample *pFrom){ - pTo->isPSample = pFrom->isPSample; - pTo->iCol = pFrom->iCol; - pTo->iHash = pFrom->iHash; - memcpy(pTo->anEq, pFrom->anEq, sizeof(tRowcnt)*p->nCol); - memcpy(pTo->anLt, pFrom->anLt, sizeof(tRowcnt)*p->nCol); - memcpy(pTo->anDLt, pFrom->anDLt, sizeof(tRowcnt)*p->nCol); - if( pFrom->nRowid ){ - sampleSetRowid(p->db, pTo, pFrom->nRowid, pFrom->u.aRowid); - }else{ - sampleSetRowidInt64(p->db, pTo, pFrom->u.iRowid); - } -} -#endif - -/* -** Reclaim all memory of a Stat4Accum structure. -*/ -static void stat4Destructor(void *pOld){ - Stat4Accum *p = (Stat4Accum*)pOld; -#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 - int i; - for(i=0; i<p->nCol; i++) sampleClear(p->db, p->aBest+i); - for(i=0; i<p->mxSample; i++) sampleClear(p->db, p->a+i); - sampleClear(p->db, &p->current); -#endif - sqlite3DbFree(p->db, p); -} - -/* -** Implementation of the stat_init(N,K,C) SQL function. The three parameters -** are: -** N: The number of columns in the index including the rowid/pk (note 1) -** K: The number of columns in the index excluding the rowid/pk. -** C: The number of rows in the index (note 2) -** -** Note 1: In the special case of the covering index that implements a -** WITHOUT ROWID table, N is the number of PRIMARY KEY columns, not the -** total number of columns in the table. -** -** Note 2: C is only used for STAT3 and STAT4. -** -** For indexes on ordinary rowid tables, N==K+1. But for indexes on -** WITHOUT ROWID tables, N=K+P where P is the number of columns in the -** PRIMARY KEY of the table. The covering index that implements the -** original WITHOUT ROWID table as N==K as a special case. -** -** This routine allocates the Stat4Accum object in heap memory. The return -** value is a pointer to the Stat4Accum object. The datatype of the -** return value is BLOB, but it is really just a pointer to the Stat4Accum -** object. -*/ -static void statInit( - sqlite3_context *context, - int argc, - sqlite3_value **argv -){ - Stat4Accum *p; - int nCol; /* Number of columns in index being sampled */ - int nKeyCol; /* Number of key columns */ - int nColUp; /* nCol rounded up for alignment */ - int n; /* Bytes of space to allocate */ - sqlite3 *db; /* Database connection */ -#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 - int mxSample = SQLITE_STAT4_SAMPLES; -#endif - - /* Decode the three function arguments */ - UNUSED_PARAMETER(argc); - nCol = sqlite3_value_int(argv[0]); - assert( nCol>0 ); - nColUp = sizeof(tRowcnt)<8 ? (nCol+1)&~1 : nCol; - nKeyCol = sqlite3_value_int(argv[1]); - assert( nKeyCol<=nCol ); - assert( nKeyCol>0 ); - - /* Allocate the space required for the Stat4Accum object */ - n = sizeof(*p) - + sizeof(tRowcnt)*nColUp /* Stat4Accum.anEq */ - + sizeof(tRowcnt)*nColUp /* Stat4Accum.anDLt */ -#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 - + sizeof(tRowcnt)*nColUp /* Stat4Accum.anLt */ - + sizeof(Stat4Sample)*(nCol+mxSample) /* Stat4Accum.aBest[], a[] */ - + sizeof(tRowcnt)*3*nColUp*(nCol+mxSample) -#endif - ; - db = sqlite3_context_db_handle(context); - p = sqlite3DbMallocZero(db, n); - if( p==0 ){ - sqlite3_result_error_nomem(context); - return; - } - - p->db = db; - p->nRow = 0; - p->nCol = nCol; - p->nKeyCol = nKeyCol; - p->current.anDLt = (tRowcnt*)&p[1]; - p->current.anEq = &p->current.anDLt[nColUp]; - -#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 - { - u8 *pSpace; /* Allocated space not yet assigned */ - int i; /* Used to iterate through p->aSample[] */ - - p->iGet = -1; - p->mxSample = mxSample; - p->nPSample = (tRowcnt)(sqlite3_value_int64(argv[2])/(mxSample/3+1) + 1); - p->current.anLt = &p->current.anEq[nColUp]; - p->iPrn = 0x689e962d*(u32)nCol ^ 0xd0944565*(u32)sqlite3_value_int(argv[2]); - - /* Set up the Stat4Accum.a[] and aBest[] arrays */ - p->a = (struct Stat4Sample*)&p->current.anLt[nColUp]; - p->aBest = &p->a[mxSample]; - pSpace = (u8*)(&p->a[mxSample+nCol]); - for(i=0; i<(mxSample+nCol); i++){ - p->a[i].anEq = (tRowcnt *)pSpace; pSpace += (sizeof(tRowcnt) * nColUp); - p->a[i].anLt = (tRowcnt *)pSpace; pSpace += (sizeof(tRowcnt) * nColUp); - p->a[i].anDLt = (tRowcnt *)pSpace; pSpace += (sizeof(tRowcnt) * nColUp); - } - assert( (pSpace - (u8*)p)==n ); - - for(i=0; i<nCol; i++){ - p->aBest[i].iCol = i; - } - } -#endif - - /* Return a pointer to the allocated object to the caller. Note that - ** only the pointer (the 2nd parameter) matters. The size of the object - ** (given by the 3rd parameter) is never used and can be any positive - ** value. */ - sqlite3_result_blob(context, p, sizeof(*p), stat4Destructor); -} -static const FuncDef statInitFuncdef = { - 2+IsStat34, /* nArg */ - SQLITE_UTF8, /* funcFlags */ - 0, /* pUserData */ - 0, /* pNext */ - statInit, /* xFunc */ - 0, /* xStep */ - 0, /* xFinalize */ - "stat_init", /* zName */ - 0, /* pHash */ - 0 /* pDestructor */ -}; - -#ifdef SQLITE_ENABLE_STAT4 -/* -** pNew and pOld are both candidate non-periodic samples selected for -** the same column (pNew->iCol==pOld->iCol). Ignoring this column and -** considering only any trailing columns and the sample hash value, this -** function returns true if sample pNew is to be preferred over pOld. -** In other words, if we assume that the cardinalities of the selected -** column for pNew and pOld are equal, is pNew to be preferred over pOld. -** -** This function assumes that for each argument sample, the contents of -** the anEq[] array from pSample->anEq[pSample->iCol+1] onwards are valid. -*/ -static int sampleIsBetterPost( - Stat4Accum *pAccum, - Stat4Sample *pNew, - Stat4Sample *pOld -){ - int nCol = pAccum->nCol; - int i; - assert( pNew->iCol==pOld->iCol ); - for(i=pNew->iCol+1; i<nCol; i++){ - if( pNew->anEq[i]>pOld->anEq[i] ) return 1; - if( pNew->anEq[i]<pOld->anEq[i] ) return 0; - } - if( pNew->iHash>pOld->iHash ) return 1; - return 0; -} -#endif - -#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 -/* -** Return true if pNew is to be preferred over pOld. -** -** This function assumes that for each argument sample, the contents of -** the anEq[] array from pSample->anEq[pSample->iCol] onwards are valid. -*/ -static int sampleIsBetter( - Stat4Accum *pAccum, - Stat4Sample *pNew, - Stat4Sample *pOld -){ - tRowcnt nEqNew = pNew->anEq[pNew->iCol]; - tRowcnt nEqOld = pOld->anEq[pOld->iCol]; - - assert( pOld->isPSample==0 && pNew->isPSample==0 ); - assert( IsStat4 || (pNew->iCol==0 && pOld->iCol==0) ); - - if( (nEqNew>nEqOld) ) return 1; -#ifdef SQLITE_ENABLE_STAT4 - if( nEqNew==nEqOld ){ - if( pNew->iCol<pOld->iCol ) return 1; - return (pNew->iCol==pOld->iCol && sampleIsBetterPost(pAccum, pNew, pOld)); - } - return 0; -#else - return (nEqNew==nEqOld && pNew->iHash>pOld->iHash); -#endif -} - -/* -** Copy the contents of sample *pNew into the p->a[] array. If necessary, -** remove the least desirable sample from p->a[] to make room. -*/ -static void sampleInsert(Stat4Accum *p, Stat4Sample *pNew, int nEqZero){ - Stat4Sample *pSample = 0; - int i; - - assert( IsStat4 || nEqZero==0 ); - -#ifdef SQLITE_ENABLE_STAT4 - if( pNew->isPSample==0 ){ - Stat4Sample *pUpgrade = 0; - assert( pNew->anEq[pNew->iCol]>0 ); - - /* This sample is being added because the prefix that ends in column - ** iCol occurs many times in the table. However, if we have already - ** added a sample that shares this prefix, there is no need to add - ** this one. Instead, upgrade the priority of the highest priority - ** existing sample that shares this prefix. */ - for(i=p->nSample-1; i>=0; i--){ - Stat4Sample *pOld = &p->a[i]; - if( pOld->anEq[pNew->iCol]==0 ){ - if( pOld->isPSample ) return; - assert( pOld->iCol>pNew->iCol ); - assert( sampleIsBetter(p, pNew, pOld) ); - if( pUpgrade==0 || sampleIsBetter(p, pOld, pUpgrade) ){ - pUpgrade = pOld; - } - } - } - if( pUpgrade ){ - pUpgrade->iCol = pNew->iCol; - pUpgrade->anEq[pUpgrade->iCol] = pNew->anEq[pUpgrade->iCol]; - goto find_new_min; - } - } -#endif - - /* If necessary, remove sample iMin to make room for the new sample. */ - if( p->nSample>=p->mxSample ){ - Stat4Sample *pMin = &p->a[p->iMin]; - tRowcnt *anEq = pMin->anEq; - tRowcnt *anLt = pMin->anLt; - tRowcnt *anDLt = pMin->anDLt; - sampleClear(p->db, pMin); - memmove(pMin, &pMin[1], sizeof(p->a[0])*(p->nSample-p->iMin-1)); - pSample = &p->a[p->nSample-1]; - pSample->nRowid = 0; - pSample->anEq = anEq; - pSample->anDLt = anDLt; - pSample->anLt = anLt; - p->nSample = p->mxSample-1; - } - - /* The "rows less-than" for the rowid column must be greater than that - ** for the last sample in the p->a[] array. Otherwise, the samples would - ** be out of order. */ -#ifdef SQLITE_ENABLE_STAT4 - assert( p->nSample==0 - || pNew->anLt[p->nCol-1] > p->a[p->nSample-1].anLt[p->nCol-1] ); -#endif - - /* Insert the new sample */ - pSample = &p->a[p->nSample]; - sampleCopy(p, pSample, pNew); - p->nSample++; - - /* Zero the first nEqZero entries in the anEq[] array. */ - memset(pSample->anEq, 0, sizeof(tRowcnt)*nEqZero); - -#ifdef SQLITE_ENABLE_STAT4 - find_new_min: -#endif - if( p->nSample>=p->mxSample ){ - int iMin = -1; - for(i=0; i<p->mxSample; i++){ - if( p->a[i].isPSample ) continue; - if( iMin<0 || sampleIsBetter(p, &p->a[iMin], &p->a[i]) ){ - iMin = i; - } - } - assert( iMin>=0 ); - p->iMin = iMin; - } -} -#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */ - -/* -** Field iChng of the index being scanned has changed. So at this point -** p->current contains a sample that reflects the previous row of the -** index. The value of anEq[iChng] and subsequent anEq[] elements are -** correct at this point. -*/ -static void samplePushPrevious(Stat4Accum *p, int iChng){ -#ifdef SQLITE_ENABLE_STAT4 - int i; - - /* Check if any samples from the aBest[] array should be pushed - ** into IndexSample.a[] at this point. */ - for(i=(p->nCol-2); i>=iChng; i--){ - Stat4Sample *pBest = &p->aBest[i]; - pBest->anEq[i] = p->current.anEq[i]; - if( p->nSample<p->mxSample || sampleIsBetter(p, pBest, &p->a[p->iMin]) ){ - sampleInsert(p, pBest, i); - } - } - - /* Update the anEq[] fields of any samples already collected. */ - for(i=p->nSample-1; i>=0; i--){ - int j; - for(j=iChng; j<p->nCol; j++){ - if( p->a[i].anEq[j]==0 ) p->a[i].anEq[j] = p->current.anEq[j]; - } - } -#endif - -#if defined(SQLITE_ENABLE_STAT3) && !defined(SQLITE_ENABLE_STAT4) - if( iChng==0 ){ - tRowcnt nLt = p->current.anLt[0]; - tRowcnt nEq = p->current.anEq[0]; - - /* Check if this is to be a periodic sample. If so, add it. */ - if( (nLt/p->nPSample)!=(nLt+nEq)/p->nPSample ){ - p->current.isPSample = 1; - sampleInsert(p, &p->current, 0); - p->current.isPSample = 0; - }else - - /* Or if it is a non-periodic sample. Add it in this case too. */ - if( p->nSample<p->mxSample - || sampleIsBetter(p, &p->current, &p->a[p->iMin]) - ){ - sampleInsert(p, &p->current, 0); - } - } -#endif - -#ifndef SQLITE_ENABLE_STAT3_OR_STAT4 - UNUSED_PARAMETER( p ); - UNUSED_PARAMETER( iChng ); -#endif -} - -/* -** Implementation of the stat_push SQL function: stat_push(P,C,R) -** Arguments: -** -** P Pointer to the Stat4Accum object created by stat_init() -** C Index of left-most column to differ from previous row -** R Rowid for the current row. Might be a key record for -** WITHOUT ROWID tables. -** -** This SQL function always returns NULL. It's purpose it to accumulate -** statistical data and/or samples in the Stat4Accum object about the -** index being analyzed. The stat_get() SQL function will later be used to -** extract relevant information for constructing the sqlite_statN tables. -** -** The R parameter is only used for STAT3 and STAT4 -*/ -static void statPush( - sqlite3_context *context, - int argc, - sqlite3_value **argv -){ - int i; - - /* The three function arguments */ - Stat4Accum *p = (Stat4Accum*)sqlite3_value_blob(argv[0]); - int iChng = sqlite3_value_int(argv[1]); - - UNUSED_PARAMETER( argc ); - UNUSED_PARAMETER( context ); - assert( p->nCol>0 ); - assert( iChng<p->nCol ); - - if( p->nRow==0 ){ - /* This is the first call to this function. Do initialization. */ - for(i=0; i<p->nCol; i++) p->current.anEq[i] = 1; - }else{ - /* Second and subsequent calls get processed here */ - samplePushPrevious(p, iChng); - - /* Update anDLt[], anLt[] and anEq[] to reflect the values that apply - ** to the current row of the index. */ - for(i=0; i<iChng; i++){ - p->current.anEq[i]++; - } - for(i=iChng; i<p->nCol; i++){ - p->current.anDLt[i]++; -#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 - p->current.anLt[i] += p->current.anEq[i]; -#endif - p->current.anEq[i] = 1; - } - } - p->nRow++; -#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 - if( sqlite3_value_type(argv[2])==SQLITE_INTEGER ){ - sampleSetRowidInt64(p->db, &p->current, sqlite3_value_int64(argv[2])); - }else{ - sampleSetRowid(p->db, &p->current, sqlite3_value_bytes(argv[2]), - sqlite3_value_blob(argv[2])); - } - p->current.iHash = p->iPrn = p->iPrn*1103515245 + 12345; -#endif - -#ifdef SQLITE_ENABLE_STAT4 - { - tRowcnt nLt = p->current.anLt[p->nCol-1]; - - /* Check if this is to be a periodic sample. If so, add it. */ - if( (nLt/p->nPSample)!=(nLt+1)/p->nPSample ){ - p->current.isPSample = 1; - p->current.iCol = 0; - sampleInsert(p, &p->current, p->nCol-1); - p->current.isPSample = 0; - } - - /* Update the aBest[] array. */ - for(i=0; i<(p->nCol-1); i++){ - p->current.iCol = i; - if( i>=iChng || sampleIsBetterPost(p, &p->current, &p->aBest[i]) ){ - sampleCopy(p, &p->aBest[i], &p->current); - } - } - } -#endif -} -static const FuncDef statPushFuncdef = { - 2+IsStat34, /* nArg */ - SQLITE_UTF8, /* funcFlags */ - 0, /* pUserData */ - 0, /* pNext */ - statPush, /* xFunc */ - 0, /* xStep */ - 0, /* xFinalize */ - "stat_push", /* zName */ - 0, /* pHash */ - 0 /* pDestructor */ -}; - -#define STAT_GET_STAT1 0 /* "stat" column of stat1 table */ -#define STAT_GET_ROWID 1 /* "rowid" column of stat[34] entry */ -#define STAT_GET_NEQ 2 /* "neq" column of stat[34] entry */ -#define STAT_GET_NLT 3 /* "nlt" column of stat[34] entry */ -#define STAT_GET_NDLT 4 /* "ndlt" column of stat[34] entry */ - -/* -** Implementation of the stat_get(P,J) SQL function. This routine is -** used to query statistical information that has been gathered into -** the Stat4Accum object by prior calls to stat_push(). The P parameter -** has type BLOB but it is really just a pointer to the Stat4Accum object. -** The content to returned is determined by the parameter J -** which is one of the STAT_GET_xxxx values defined above. -** -** If neither STAT3 nor STAT4 are enabled, then J is always -** STAT_GET_STAT1 and is hence omitted and this routine becomes -** a one-parameter function, stat_get(P), that always returns the -** stat1 table entry information. -*/ -static void statGet( - sqlite3_context *context, - int argc, - sqlite3_value **argv -){ - Stat4Accum *p = (Stat4Accum*)sqlite3_value_blob(argv[0]); -#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 - /* STAT3 and STAT4 have a parameter on this routine. */ - int eCall = sqlite3_value_int(argv[1]); - assert( argc==2 ); - assert( eCall==STAT_GET_STAT1 || eCall==STAT_GET_NEQ - || eCall==STAT_GET_ROWID || eCall==STAT_GET_NLT - || eCall==STAT_GET_NDLT - ); - if( eCall==STAT_GET_STAT1 ) -#else - assert( argc==1 ); -#endif - { - /* Return the value to store in the "stat" column of the sqlite_stat1 - ** table for this index. - ** - ** The value is a string composed of a list of integers describing - ** the index. The first integer in the list is the total number of - ** entries in the index. There is one additional integer in the list - ** for each indexed column. This additional integer is an estimate of - ** the number of rows matched by a stabbing query on the index using - ** a key with the corresponding number of fields. In other words, - ** if the index is on columns (a,b) and the sqlite_stat1 value is - ** "100 10 2", then SQLite estimates that: - ** - ** * the index contains 100 rows, - ** * "WHERE a=?" matches 10 rows, and - ** * "WHERE a=? AND b=?" matches 2 rows. - ** - ** If D is the count of distinct values and K is the total number of - ** rows, then each estimate is computed as: - ** - ** I = (K+D-1)/D - */ - char *z; - int i; - - char *zRet = sqlite3MallocZero( (p->nKeyCol+1)*25 ); - if( zRet==0 ){ - sqlite3_result_error_nomem(context); - return; - } - - sqlite3_snprintf(24, zRet, "%llu", (u64)p->nRow); - z = zRet + sqlite3Strlen30(zRet); - for(i=0; i<p->nKeyCol; i++){ - u64 nDistinct = p->current.anDLt[i] + 1; - u64 iVal = (p->nRow + nDistinct - 1) / nDistinct; - sqlite3_snprintf(24, z, " %llu", iVal); - z += sqlite3Strlen30(z); - assert( p->current.anEq[i] ); - } - assert( z[0]=='\0' && z>zRet ); - - sqlite3_result_text(context, zRet, -1, sqlite3_free); - } -#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 - else if( eCall==STAT_GET_ROWID ){ - if( p->iGet<0 ){ - samplePushPrevious(p, 0); - p->iGet = 0; - } - if( p->iGet<p->nSample ){ - Stat4Sample *pS = p->a + p->iGet; - if( pS->nRowid==0 ){ - sqlite3_result_int64(context, pS->u.iRowid); - }else{ - sqlite3_result_blob(context, pS->u.aRowid, pS->nRowid, - SQLITE_TRANSIENT); - } - } - }else{ - tRowcnt *aCnt = 0; - - assert( p->iGet<p->nSample ); - switch( eCall ){ - case STAT_GET_NEQ: aCnt = p->a[p->iGet].anEq; break; - case STAT_GET_NLT: aCnt = p->a[p->iGet].anLt; break; - default: { - aCnt = p->a[p->iGet].anDLt; - p->iGet++; - break; - } - } - - if( IsStat3 ){ - sqlite3_result_int64(context, (i64)aCnt[0]); - }else{ - char *zRet = sqlite3MallocZero(p->nCol * 25); - if( zRet==0 ){ - sqlite3_result_error_nomem(context); - }else{ - int i; - char *z = zRet; - for(i=0; i<p->nCol; i++){ - sqlite3_snprintf(24, z, "%llu ", (u64)aCnt[i]); - z += sqlite3Strlen30(z); - } - assert( z[0]=='\0' && z>zRet ); - z[-1] = '\0'; - sqlite3_result_text(context, zRet, -1, sqlite3_free); - } - } - } -#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */ -#ifndef SQLITE_DEBUG - UNUSED_PARAMETER( argc ); -#endif -} -static const FuncDef statGetFuncdef = { - 1+IsStat34, /* nArg */ - SQLITE_UTF8, /* funcFlags */ - 0, /* pUserData */ - 0, /* pNext */ - statGet, /* xFunc */ - 0, /* xStep */ - 0, /* xFinalize */ - "stat_get", /* zName */ - 0, /* pHash */ - 0 /* pDestructor */ -}; - -static void callStatGet(Vdbe *v, int regStat4, int iParam, int regOut){ - assert( regOut!=regStat4 && regOut!=regStat4+1 ); -#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 - sqlite3VdbeAddOp2(v, OP_Integer, iParam, regStat4+1); -#elif SQLITE_DEBUG - assert( iParam==STAT_GET_STAT1 ); -#else - UNUSED_PARAMETER( iParam ); -#endif - sqlite3VdbeAddOp3(v, OP_Function0, 0, regStat4, regOut); - sqlite3VdbeChangeP4(v, -1, (char*)&statGetFuncdef, P4_FUNCDEF); - sqlite3VdbeChangeP5(v, 1 + IsStat34); -} - -/* -** Generate code to do an analysis of all indices associated with -** a single table. -*/ -static void analyzeOneTable( - Parse *pParse, /* Parser context */ - Table *pTab, /* Table whose indices are to be analyzed */ - Index *pOnlyIdx, /* If not NULL, only analyze this one index */ - int iStatCur, /* Index of VdbeCursor that writes the sqlite_stat1 table */ - int iMem, /* Available memory locations begin here */ - int iTab /* Next available cursor */ -){ - sqlite3 *db = pParse->db; /* Database handle */ - Index *pIdx; /* An index to being analyzed */ - int iIdxCur; /* Cursor open on index being analyzed */ - int iTabCur; /* Table cursor */ - Vdbe *v; /* The virtual machine being built up */ - int i; /* Loop counter */ - 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 regNewRowid = iMem++; /* Rowid for the inserted record */ - int regStat4 = iMem++; /* Register to hold Stat4Accum object */ - int regChng = iMem++; /* Index of changed index field */ -#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 - int regRowid = iMem++; /* Rowid argument passed to stat_push() */ -#endif - int regTemp = iMem++; /* Temporary use register */ - int regTabname = iMem++; /* Register containing table name */ - int regIdxname = iMem++; /* Register containing index name */ - int regStat1 = iMem++; /* Value for the stat column of sqlite_stat1 */ - int regPrev = iMem; /* MUST BE LAST (see below) */ - - pParse->nMem = MAX(pParse->nMem, iMem); - v = sqlite3GetVdbe(pParse); - if( v==0 || NEVER(pTab==0) ){ - return; - } - if( pTab->tnum==0 ){ - /* Do not gather statistics on views or virtual tables */ - return; - } - if( sqlite3_strnicmp(pTab->zName, "sqlite_", 7)==0 ){ - /* Do not gather statistics on system tables */ - return; - } - assert( sqlite3BtreeHoldsAllMutexes(db) ); - iDb = sqlite3SchemaToIndex(db, pTab->pSchema); - assert( iDb>=0 ); - assert( sqlite3SchemaMutexHeld(db, iDb, 0) ); -#ifndef SQLITE_OMIT_AUTHORIZATION - if( sqlite3AuthCheck(pParse, SQLITE_ANALYZE, pTab->zName, 0, - db->aDb[iDb].zName ) ){ - return; - } -#endif - - /* Establish a read-lock on the table at the shared-cache level. - ** Open a read-only cursor on the table. Also allocate a cursor number - ** to use for scanning indexes (iIdxCur). No index cursor is opened at - ** this time though. */ - sqlite3TableLock(pParse, iDb, pTab->tnum, 0, pTab->zName); - iTabCur = iTab++; - iIdxCur = iTab++; - pParse->nTab = MAX(pParse->nTab, iTab); - sqlite3OpenTable(pParse, iTabCur, iDb, pTab, OP_OpenRead); - sqlite3VdbeLoadString(v, regTabname, pTab->zName); - - for(pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext){ - int nCol; /* Number of columns in pIdx. "N" */ - int addrRewind; /* Address of "OP_Rewind iIdxCur" */ - int addrNextRow; /* Address of "next_row:" */ - const char *zIdxName; /* Name of the index */ - int nColTest; /* Number of columns to test for changes */ - - if( pOnlyIdx && pOnlyIdx!=pIdx ) continue; - if( pIdx->pPartIdxWhere==0 ) needTableCnt = 0; - if( !HasRowid(pTab) && IsPrimaryKeyIndex(pIdx) ){ - nCol = pIdx->nKeyCol; - zIdxName = pTab->zName; - nColTest = nCol - 1; - }else{ - nCol = pIdx->nColumn; - zIdxName = pIdx->zName; - nColTest = pIdx->uniqNotNull ? pIdx->nKeyCol-1 : nCol-1; - } - - /* Populate the register containing the index name. */ - sqlite3VdbeLoadString(v, regIdxname, zIdxName); - VdbeComment((v, "Analysis for %s.%s", pTab->zName, zIdxName)); - - /* - ** Pseudo-code for loop that calls stat_push(): - ** - ** Rewind csr - ** if eof(csr) goto end_of_scan; - ** regChng = 0 - ** goto chng_addr_0; - ** - ** next_row: - ** regChng = 0 - ** if( idx(0) != regPrev(0) ) goto chng_addr_0 - ** regChng = 1 - ** if( idx(1) != regPrev(1) ) goto chng_addr_1 - ** ... - ** regChng = N - ** goto chng_addr_N - ** - ** chng_addr_0: - ** regPrev(0) = idx(0) - ** chng_addr_1: - ** regPrev(1) = idx(1) - ** ... - ** - ** endDistinctTest: - ** regRowid = idx(rowid) - ** stat_push(P, regChng, regRowid) - ** Next csr - ** if !eof(csr) goto next_row; - ** - ** end_of_scan: - */ - - /* Make sure there are enough memory cells allocated to accommodate - ** the regPrev array and a trailing rowid (the rowid slot is required - ** when building a record to insert into the sample column of - ** the sqlite_stat4 table. */ - pParse->nMem = MAX(pParse->nMem, regPrev+nColTest); - - /* Open a read-only cursor on the index being analyzed. */ - assert( iDb==sqlite3SchemaToIndex(db, pIdx->pSchema) ); - sqlite3VdbeAddOp3(v, OP_OpenRead, iIdxCur, pIdx->tnum, iDb); - sqlite3VdbeSetP4KeyInfo(pParse, pIdx); - VdbeComment((v, "%s", pIdx->zName)); - - /* Invoke the stat_init() function. The arguments are: - ** - ** (1) the number of columns in the index including the rowid - ** (or for a WITHOUT ROWID table, the number of PK columns), - ** (2) the number of columns in the key without the rowid/pk - ** (3) the number of rows in the index, - ** - ** - ** The third argument is only used for STAT3 and STAT4 - */ -#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 - sqlite3VdbeAddOp2(v, OP_Count, iIdxCur, regStat4+3); -#endif - sqlite3VdbeAddOp2(v, OP_Integer, nCol, regStat4+1); - sqlite3VdbeAddOp2(v, OP_Integer, pIdx->nKeyCol, regStat4+2); - sqlite3VdbeAddOp3(v, OP_Function0, 0, regStat4+1, regStat4); - sqlite3VdbeChangeP4(v, -1, (char*)&statInitFuncdef, P4_FUNCDEF); - sqlite3VdbeChangeP5(v, 2+IsStat34); - - /* Implementation of the following: - ** - ** Rewind csr - ** if eof(csr) goto end_of_scan; - ** regChng = 0 - ** goto next_push_0; - ** - */ - addrRewind = sqlite3VdbeAddOp1(v, OP_Rewind, iIdxCur); - VdbeCoverage(v); - sqlite3VdbeAddOp2(v, OP_Integer, 0, regChng); - addrNextRow = sqlite3VdbeCurrentAddr(v); - - if( nColTest>0 ){ - int endDistinctTest = sqlite3VdbeMakeLabel(v); - int *aGotoChng; /* Array of jump instruction addresses */ - aGotoChng = sqlite3DbMallocRaw(db, sizeof(int)*nColTest); - if( aGotoChng==0 ) continue; - - /* - ** next_row: - ** regChng = 0 - ** if( idx(0) != regPrev(0) ) goto chng_addr_0 - ** regChng = 1 - ** if( idx(1) != regPrev(1) ) goto chng_addr_1 - ** ... - ** regChng = N - ** goto endDistinctTest - */ - sqlite3VdbeAddOp0(v, OP_Goto); - addrNextRow = sqlite3VdbeCurrentAddr(v); - if( nColTest==1 && pIdx->nKeyCol==1 && IsUniqueIndex(pIdx) ){ - /* For a single-column UNIQUE index, once we have found a non-NULL - ** row, we know that all the rest will be distinct, so skip - ** subsequent distinctness tests. */ - sqlite3VdbeAddOp2(v, OP_NotNull, regPrev, endDistinctTest); - VdbeCoverage(v); - } - for(i=0; i<nColTest; i++){ - char *pColl = (char*)sqlite3LocateCollSeq(pParse, pIdx->azColl[i]); - sqlite3VdbeAddOp2(v, OP_Integer, i, regChng); - sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regTemp); - aGotoChng[i] = - sqlite3VdbeAddOp4(v, OP_Ne, regTemp, 0, regPrev+i, pColl, P4_COLLSEQ); - sqlite3VdbeChangeP5(v, SQLITE_NULLEQ); - VdbeCoverage(v); - } - sqlite3VdbeAddOp2(v, OP_Integer, nColTest, regChng); - sqlite3VdbeGoto(v, endDistinctTest); - - - /* - ** chng_addr_0: - ** regPrev(0) = idx(0) - ** chng_addr_1: - ** regPrev(1) = idx(1) - ** ... - */ - sqlite3VdbeJumpHere(v, addrNextRow-1); - for(i=0; i<nColTest; i++){ - sqlite3VdbeJumpHere(v, aGotoChng[i]); - sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, i, regPrev+i); - } - sqlite3VdbeResolveLabel(v, endDistinctTest); - sqlite3DbFree(db, aGotoChng); - } - - /* - ** chng_addr_N: - ** regRowid = idx(rowid) // STAT34 only - ** stat_push(P, regChng, regRowid) // 3rd parameter STAT34 only - ** Next csr - ** if !eof(csr) goto next_row; - */ -#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 - assert( regRowid==(regStat4+2) ); - if( HasRowid(pTab) ){ - sqlite3VdbeAddOp2(v, OP_IdxRowid, iIdxCur, regRowid); - }else{ - Index *pPk = sqlite3PrimaryKeyIndex(pIdx->pTable); - int j, k, regKey; - regKey = sqlite3GetTempRange(pParse, pPk->nKeyCol); - for(j=0; j<pPk->nKeyCol; j++){ - k = sqlite3ColumnOfIndex(pIdx, pPk->aiColumn[j]); - assert( k>=0 && k<pTab->nCol ); - sqlite3VdbeAddOp3(v, OP_Column, iIdxCur, k, regKey+j); - VdbeComment((v, "%s", pTab->aCol[pPk->aiColumn[j]].zName)); - } - sqlite3VdbeAddOp3(v, OP_MakeRecord, regKey, pPk->nKeyCol, regRowid); - sqlite3ReleaseTempRange(pParse, regKey, pPk->nKeyCol); - } -#endif - assert( regChng==(regStat4+1) ); - sqlite3VdbeAddOp3(v, OP_Function0, 1, regStat4, regTemp); - sqlite3VdbeChangeP4(v, -1, (char*)&statPushFuncdef, P4_FUNCDEF); - sqlite3VdbeChangeP5(v, 2+IsStat34); - sqlite3VdbeAddOp2(v, OP_Next, iIdxCur, addrNextRow); VdbeCoverage(v); - - /* Add the entry to the stat1 table. */ - callStatGet(v, regStat4, STAT_GET_STAT1, regStat1); - assert( "BBB"[0]==SQLITE_AFF_TEXT ); - sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regTemp, "BBB", 0); - sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regNewRowid); - sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regTemp, regNewRowid); - sqlite3VdbeChangeP5(v, OPFLAG_APPEND); - - /* Add the entries to the stat3 or stat4 table. */ -#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 - { - int regEq = regStat1; - int regLt = regStat1+1; - int regDLt = regStat1+2; - int regSample = regStat1+3; - int regCol = regStat1+4; - int regSampleRowid = regCol + nCol; - int addrNext; - int addrIsNull; - u8 seekOp = HasRowid(pTab) ? OP_NotExists : OP_NotFound; - - pParse->nMem = MAX(pParse->nMem, regCol+nCol); - - addrNext = sqlite3VdbeCurrentAddr(v); - callStatGet(v, regStat4, STAT_GET_ROWID, regSampleRowid); - addrIsNull = sqlite3VdbeAddOp1(v, OP_IsNull, regSampleRowid); - VdbeCoverage(v); - callStatGet(v, regStat4, STAT_GET_NEQ, regEq); - callStatGet(v, regStat4, STAT_GET_NLT, regLt); - callStatGet(v, regStat4, STAT_GET_NDLT, regDLt); - sqlite3VdbeAddOp4Int(v, seekOp, iTabCur, addrNext, regSampleRowid, 0); - /* We know that the regSampleRowid row exists because it was read by - ** the previous loop. Thus the not-found jump of seekOp will never - ** be taken */ - VdbeCoverageNeverTaken(v); -#ifdef SQLITE_ENABLE_STAT3 - sqlite3ExprCodeLoadIndexColumn(pParse, pIdx, iTabCur, 0, regSample); -#else - for(i=0; i<nCol; i++){ - sqlite3ExprCodeLoadIndexColumn(pParse, pIdx, iTabCur, i, regCol+i); - } - sqlite3VdbeAddOp3(v, OP_MakeRecord, regCol, nCol, regSample); -#endif - sqlite3VdbeAddOp3(v, OP_MakeRecord, regTabname, 6, regTemp); - sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur+1, regNewRowid); - sqlite3VdbeAddOp3(v, OP_Insert, iStatCur+1, regTemp, regNewRowid); - sqlite3VdbeAddOp2(v, OP_Goto, 1, addrNext); /* P1==1 for end-of-loop */ - sqlite3VdbeJumpHere(v, addrIsNull); - } -#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */ - - /* End of analysis */ - sqlite3VdbeJumpHere(v, addrRewind); - } - - - /* Create a single sqlite_stat1 entry containing NULL as the index - ** name and the row count as the content. - */ - if( pOnlyIdx==0 && needTableCnt ){ - VdbeComment((v, "%s", pTab->zName)); - sqlite3VdbeAddOp2(v, OP_Count, iTabCur, regStat1); - jZeroRows = sqlite3VdbeAddOp1(v, OP_IfNot, regStat1); VdbeCoverage(v); - sqlite3VdbeAddOp2(v, OP_Null, 0, regIdxname); - assert( "BBB"[0]==SQLITE_AFF_TEXT ); - sqlite3VdbeAddOp4(v, OP_MakeRecord, regTabname, 3, regTemp, "BBB", 0); - sqlite3VdbeAddOp2(v, OP_NewRowid, iStatCur, regNewRowid); - sqlite3VdbeAddOp3(v, OP_Insert, iStatCur, regTemp, regNewRowid); - sqlite3VdbeChangeP5(v, OPFLAG_APPEND); - sqlite3VdbeJumpHere(v, jZeroRows); - } -} - - -/* -** Generate code that will cause the most recent index analysis to -** be loaded into internal hash tables where is can be used. -*/ -static void loadAnalysis(Parse *pParse, int iDb){ - Vdbe *v = sqlite3GetVdbe(pParse); - if( v ){ - sqlite3VdbeAddOp1(v, OP_LoadAnalysis, iDb); - } -} - -/* -** Generate code that will do an analysis of an entire database -*/ -static void analyzeDatabase(Parse *pParse, int iDb){ - sqlite3 *db = pParse->db; - Schema *pSchema = db->aDb[iDb].pSchema; /* Schema of database iDb */ - HashElem *k; - int iStatCur; - int iMem; - int iTab; - - sqlite3BeginWriteOperation(pParse, 0, iDb); - iStatCur = pParse->nTab; - pParse->nTab += 3; - openStatTable(pParse, iDb, iStatCur, 0, 0); - iMem = pParse->nMem+1; - iTab = pParse->nTab; - assert( sqlite3SchemaMutexHeld(db, iDb, 0) ); - for(k=sqliteHashFirst(&pSchema->tblHash); k; k=sqliteHashNext(k)){ - Table *pTab = (Table*)sqliteHashData(k); - analyzeOneTable(pParse, pTab, 0, iStatCur, iMem, iTab); - } - loadAnalysis(pParse, iDb); -} - -/* -** Generate code that will do an analysis of a single table in -** a database. If pOnlyIdx is not NULL then it is a single index -** in pTab that should be analyzed. -*/ -static void analyzeTable(Parse *pParse, Table *pTab, Index *pOnlyIdx){ - int iDb; - int iStatCur; - - assert( pTab!=0 ); - assert( sqlite3BtreeHoldsAllMutexes(pParse->db) ); - iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema); - sqlite3BeginWriteOperation(pParse, 0, iDb); - iStatCur = pParse->nTab; - pParse->nTab += 3; - if( pOnlyIdx ){ - openStatTable(pParse, iDb, iStatCur, pOnlyIdx->zName, "idx"); - }else{ - openStatTable(pParse, iDb, iStatCur, pTab->zName, "tbl"); - } - analyzeOneTable(pParse, pTab, pOnlyIdx, iStatCur,pParse->nMem+1,pParse->nTab); - loadAnalysis(pParse, iDb); -} - -/* -** Generate code for the ANALYZE command. The parser calls this routine -** when it recognizes an ANALYZE command. -** -** ANALYZE -- 1 -** ANALYZE <database> -- 2 -** ANALYZE ?<database>.?<tablename> -- 3 -** -** Form 1 causes all indices in all attached databases to be analyzed. -** Form 2 analyzes all indices the single database named. -** Form 3 analyzes all indices associated with the named table. -*/ -void sqlite3Analyze(Parse *pParse, Token *pName1, Token *pName2){ - sqlite3 *db = pParse->db; - int iDb; - int i; - char *z, *zDb; - Table *pTab; - Index *pIdx; - Token *pTableName; - Vdbe *v; - - /* Read the database schema. If an error occurs, leave an error message - ** and code in pParse and return NULL. */ - assert( sqlite3BtreeHoldsAllMutexes(pParse->db) ); - if( SQLITE_OK!=sqlite3ReadSchema(pParse) ){ - return; - } - - assert( pName2!=0 || pName1==0 ); - if( pName1==0 ){ - /* Form 1: Analyze everything */ - for(i=0; i<db->nDb; i++){ - if( i==1 ) continue; /* Do not analyze the TEMP database */ - analyzeDatabase(pParse, i); - } - }else if( pName2->n==0 ){ - /* Form 2: Analyze the database or table named */ - iDb = sqlite3FindDb(db, pName1); - if( iDb>=0 ){ - analyzeDatabase(pParse, iDb); - }else{ - z = sqlite3NameFromToken(db, pName1); - if( z ){ - if( (pIdx = sqlite3FindIndex(db, z, 0))!=0 ){ - analyzeTable(pParse, pIdx->pTable, pIdx); - }else if( (pTab = sqlite3LocateTable(pParse, 0, z, 0))!=0 ){ - analyzeTable(pParse, pTab, 0); - } - sqlite3DbFree(db, z); - } - } - }else{ - /* Form 3: Analyze the fully qualified table name */ - iDb = sqlite3TwoPartName(pParse, pName1, pName2, &pTableName); - if( iDb>=0 ){ - zDb = db->aDb[iDb].zName; - z = sqlite3NameFromToken(db, pTableName); - if( z ){ - if( (pIdx = sqlite3FindIndex(db, z, zDb))!=0 ){ - analyzeTable(pParse, pIdx->pTable, pIdx); - }else if( (pTab = sqlite3LocateTable(pParse, 0, z, zDb))!=0 ){ - analyzeTable(pParse, pTab, 0); - } - sqlite3DbFree(db, z); - } - } - } - v = sqlite3GetVdbe(pParse); - if( v ) sqlite3VdbeAddOp0(v, OP_Expire); -} - -/* -** Used to pass information from the analyzer reader through to the -** callback routine. -*/ -typedef struct analysisInfo analysisInfo; -struct analysisInfo { - sqlite3 *db; - const char *zDatabase; -}; - -/* -** The first argument points to a nul-terminated string containing a -** list of space separated integers. Read the first nOut of these into -** the array aOut[]. -*/ -static void decodeIntArray( - char *zIntArray, /* String containing int array to decode */ - int nOut, /* Number of slots in aOut[] */ - tRowcnt *aOut, /* Store integers here */ - LogEst *aLog, /* Or, if aOut==0, here */ - Index *pIndex /* Handle extra flags for this index, if not NULL */ -){ - char *z = zIntArray; - int c; - int i; - tRowcnt v; - -#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 - if( z==0 ) z = ""; -#else - assert( z!=0 ); -#endif - for(i=0; *z && i<nOut; i++){ - v = 0; - while( (c=z[0])>='0' && c<='9' ){ - v = v*10 + c - '0'; - z++; - } -#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 - if( aOut ) aOut[i] = v; - if( aLog ) aLog[i] = sqlite3LogEst(v); -#else - assert( aOut==0 ); - UNUSED_PARAMETER(aOut); - assert( aLog!=0 ); - aLog[i] = sqlite3LogEst(v); -#endif - if( *z==' ' ) z++; - } -#ifndef SQLITE_ENABLE_STAT3_OR_STAT4 - assert( pIndex!=0 ); { -#else - if( pIndex ){ -#endif - pIndex->bUnordered = 0; - pIndex->noSkipScan = 0; - while( z[0] ){ - if( sqlite3_strglob("unordered*", z)==0 ){ - pIndex->bUnordered = 1; - }else if( sqlite3_strglob("sz=[0-9]*", z)==0 ){ - pIndex->szIdxRow = sqlite3LogEst(sqlite3Atoi(z+3)); - }else if( sqlite3_strglob("noskipscan*", z)==0 ){ - pIndex->noSkipScan = 1; - } -#ifdef SQLITE_ENABLE_COSTMULT - else if( sqlite3_strglob("costmult=[0-9]*",z)==0 ){ - pIndex->pTable->costMult = sqlite3LogEst(sqlite3Atoi(z+9)); - } -#endif - while( z[0]!=0 && z[0]!=' ' ) z++; - while( z[0]==' ' ) z++; - } - } -} - -/* -** This callback is invoked once for each index when reading the -** sqlite_stat1 table. -** -** argv[0] = name of the table -** argv[1] = name of the index (might be NULL) -** argv[2] = results of analysis - on integer for each column -** -** Entries for which argv[1]==NULL simply record the number of rows in -** the table. -*/ -static int analysisLoader(void *pData, int argc, char **argv, char **NotUsed){ - analysisInfo *pInfo = (analysisInfo*)pData; - Index *pIndex; - Table *pTable; - const char *z; - - assert( argc==3 ); - UNUSED_PARAMETER2(NotUsed, argc); - - if( argv==0 || argv[0]==0 || argv[2]==0 ){ - return 0; - } - pTable = sqlite3FindTable(pInfo->db, argv[0], pInfo->zDatabase); - if( pTable==0 ){ - return 0; - } - if( argv[1]==0 ){ - pIndex = 0; - }else if( sqlite3_stricmp(argv[0],argv[1])==0 ){ - pIndex = sqlite3PrimaryKeyIndex(pTable); - }else{ - pIndex = sqlite3FindIndex(pInfo->db, argv[1], pInfo->zDatabase); - } - z = argv[2]; - - if( pIndex ){ - tRowcnt *aiRowEst = 0; - int nCol = pIndex->nKeyCol+1; -#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 - /* Index.aiRowEst may already be set here if there are duplicate - ** sqlite_stat1 entries for this index. In that case just clobber - ** the old data with the new instead of allocating a new array. */ - if( pIndex->aiRowEst==0 ){ - pIndex->aiRowEst = (tRowcnt*)sqlite3MallocZero(sizeof(tRowcnt) * nCol); - if( pIndex->aiRowEst==0 ) pInfo->db->mallocFailed = 1; - } - aiRowEst = pIndex->aiRowEst; -#endif - pIndex->bUnordered = 0; - decodeIntArray((char*)z, nCol, aiRowEst, pIndex->aiRowLogEst, pIndex); - if( pIndex->pPartIdxWhere==0 ) pTable->nRowLogEst = pIndex->aiRowLogEst[0]; - }else{ - Index fakeIdx; - fakeIdx.szIdxRow = pTable->szTabRow; -#ifdef SQLITE_ENABLE_COSTMULT - fakeIdx.pTable = pTable; -#endif - decodeIntArray((char*)z, 1, 0, &pTable->nRowLogEst, &fakeIdx); - pTable->szTabRow = fakeIdx.szIdxRow; - } - - return 0; -} - -/* -** If the Index.aSample variable is not NULL, delete the aSample[] array -** and its contents. -*/ -void sqlite3DeleteIndexSamples(sqlite3 *db, Index *pIdx){ -#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 - if( pIdx->aSample ){ - int j; - for(j=0; j<pIdx->nSample; j++){ - IndexSample *p = &pIdx->aSample[j]; - sqlite3DbFree(db, p->p); - } - sqlite3DbFree(db, pIdx->aSample); - } - if( db && db->pnBytesFreed==0 ){ - pIdx->nSample = 0; - pIdx->aSample = 0; - } -#else - UNUSED_PARAMETER(db); - UNUSED_PARAMETER(pIdx); -#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */ -} - -#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 -/* -** Populate the pIdx->aAvgEq[] array based on the samples currently -** stored in pIdx->aSample[]. -*/ -static void initAvgEq(Index *pIdx){ - if( pIdx ){ - IndexSample *aSample = pIdx->aSample; - IndexSample *pFinal = &aSample[pIdx->nSample-1]; - int iCol; - int nCol = 1; - if( pIdx->nSampleCol>1 ){ - /* If this is stat4 data, then calculate aAvgEq[] values for all - ** sample columns except the last. The last is always set to 1, as - ** once the trailing PK fields are considered all index keys are - ** unique. */ - nCol = pIdx->nSampleCol-1; - pIdx->aAvgEq[nCol] = 1; - } - for(iCol=0; iCol<nCol; iCol++){ - int nSample = pIdx->nSample; - int i; /* Used to iterate through samples */ - tRowcnt sumEq = 0; /* Sum of the nEq values */ - tRowcnt avgEq = 0; - tRowcnt nRow; /* Number of rows in index */ - i64 nSum100 = 0; /* Number of terms contributing to sumEq */ - i64 nDist100; /* Number of distinct values in index */ - - if( !pIdx->aiRowEst || iCol>=pIdx->nKeyCol || pIdx->aiRowEst[iCol+1]==0 ){ - nRow = pFinal->anLt[iCol]; - nDist100 = (i64)100 * pFinal->anDLt[iCol]; - nSample--; - }else{ - nRow = pIdx->aiRowEst[0]; - nDist100 = ((i64)100 * pIdx->aiRowEst[0]) / pIdx->aiRowEst[iCol+1]; - } - pIdx->nRowEst0 = nRow; - - /* Set nSum to the number of distinct (iCol+1) field prefixes that - ** occur in the stat4 table for this index. Set sumEq to the sum of - ** the nEq values for column iCol for the same set (adding the value - ** only once where there exist duplicate prefixes). */ - for(i=0; i<nSample; i++){ - if( i==(pIdx->nSample-1) - || aSample[i].anDLt[iCol]!=aSample[i+1].anDLt[iCol] - ){ - sumEq += aSample[i].anEq[iCol]; - nSum100 += 100; - } - } - - if( nDist100>nSum100 ){ - avgEq = ((i64)100 * (nRow - sumEq))/(nDist100 - nSum100); - } - if( avgEq==0 ) avgEq = 1; - pIdx->aAvgEq[iCol] = avgEq; - } - } -} - -/* -** Look up an index by name. Or, if the name of a WITHOUT ROWID table -** is supplied instead, find the PRIMARY KEY index for that table. -*/ -static Index *findIndexOrPrimaryKey( - sqlite3 *db, - const char *zName, - const char *zDb -){ - Index *pIdx = sqlite3FindIndex(db, zName, zDb); - if( pIdx==0 ){ - Table *pTab = sqlite3FindTable(db, zName, zDb); - if( pTab && !HasRowid(pTab) ) pIdx = sqlite3PrimaryKeyIndex(pTab); - } - return pIdx; -} - -/* -** Load the content from either the sqlite_stat4 or sqlite_stat3 table -** into the relevant Index.aSample[] arrays. -** -** Arguments zSql1 and zSql2 must point to SQL statements that return -** data equivalent to the following (statements are different for stat3, -** see the caller of this function for details): -** -** zSql1: SELECT idx,count(*) FROM %Q.sqlite_stat4 GROUP BY idx -** zSql2: SELECT idx,neq,nlt,ndlt,sample FROM %Q.sqlite_stat4 -** -** where %Q is replaced with the database name before the SQL is executed. -*/ -static int loadStatTbl( - sqlite3 *db, /* Database handle */ - int bStat3, /* Assume single column records only */ - const char *zSql1, /* SQL statement 1 (see above) */ - const char *zSql2, /* SQL statement 2 (see above) */ - const char *zDb /* Database name (e.g. "main") */ -){ - int rc; /* Result codes from subroutines */ - sqlite3_stmt *pStmt = 0; /* An SQL statement being run */ - char *zSql; /* Text of the SQL statement */ - Index *pPrevIdx = 0; /* Previous index in the loop */ - IndexSample *pSample; /* A slot in pIdx->aSample[] */ - - assert( db->lookaside.bEnabled==0 ); - zSql = sqlite3MPrintf(db, zSql1, zDb); - if( !zSql ){ - return SQLITE_NOMEM; - } - rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0); - sqlite3DbFree(db, zSql); - if( rc ) return rc; - - while( sqlite3_step(pStmt)==SQLITE_ROW ){ - int nIdxCol = 1; /* Number of columns in stat4 records */ - - char *zIndex; /* Index name */ - Index *pIdx; /* Pointer to the index object */ - int nSample; /* Number of samples */ - int nByte; /* Bytes of space required */ - int i; /* Bytes of space required */ - tRowcnt *pSpace; - - zIndex = (char *)sqlite3_column_text(pStmt, 0); - if( zIndex==0 ) continue; - nSample = sqlite3_column_int(pStmt, 1); - pIdx = findIndexOrPrimaryKey(db, zIndex, zDb); - assert( pIdx==0 || bStat3 || pIdx->nSample==0 ); - /* Index.nSample is non-zero at this point if data has already been - ** loaded from the stat4 table. In this case ignore stat3 data. */ - if( pIdx==0 || pIdx->nSample ) continue; - if( bStat3==0 ){ - assert( !HasRowid(pIdx->pTable) || pIdx->nColumn==pIdx->nKeyCol+1 ); - if( !HasRowid(pIdx->pTable) && IsPrimaryKeyIndex(pIdx) ){ - nIdxCol = pIdx->nKeyCol; - }else{ - nIdxCol = pIdx->nColumn; - } - } - pIdx->nSampleCol = nIdxCol; - nByte = sizeof(IndexSample) * nSample; - nByte += sizeof(tRowcnt) * nIdxCol * 3 * nSample; - nByte += nIdxCol * sizeof(tRowcnt); /* Space for Index.aAvgEq[] */ - - pIdx->aSample = sqlite3DbMallocZero(db, nByte); - if( pIdx->aSample==0 ){ - sqlite3_finalize(pStmt); - return SQLITE_NOMEM; - } - pSpace = (tRowcnt*)&pIdx->aSample[nSample]; - pIdx->aAvgEq = pSpace; pSpace += nIdxCol; - for(i=0; i<nSample; i++){ - pIdx->aSample[i].anEq = pSpace; pSpace += nIdxCol; - pIdx->aSample[i].anLt = pSpace; pSpace += nIdxCol; - pIdx->aSample[i].anDLt = pSpace; pSpace += nIdxCol; - } - assert( ((u8*)pSpace)-nByte==(u8*)(pIdx->aSample) ); - } - rc = sqlite3_finalize(pStmt); - if( rc ) return rc; - - zSql = sqlite3MPrintf(db, zSql2, zDb); - if( !zSql ){ - return SQLITE_NOMEM; - } - rc = sqlite3_prepare(db, zSql, -1, &pStmt, 0); - sqlite3DbFree(db, zSql); - if( rc ) return rc; - - while( sqlite3_step(pStmt)==SQLITE_ROW ){ - char *zIndex; /* Index name */ - Index *pIdx; /* Pointer to the index object */ - int nCol = 1; /* Number of columns in index */ - - zIndex = (char *)sqlite3_column_text(pStmt, 0); - if( zIndex==0 ) continue; - pIdx = findIndexOrPrimaryKey(db, zIndex, zDb); - if( pIdx==0 ) continue; - /* This next condition is true if data has already been loaded from - ** the sqlite_stat4 table. In this case ignore stat3 data. */ - nCol = pIdx->nSampleCol; - if( bStat3 && nCol>1 ) continue; - if( pIdx!=pPrevIdx ){ - initAvgEq(pPrevIdx); - pPrevIdx = pIdx; - } - pSample = &pIdx->aSample[pIdx->nSample]; - decodeIntArray((char*)sqlite3_column_text(pStmt,1),nCol,pSample->anEq,0,0); - decodeIntArray((char*)sqlite3_column_text(pStmt,2),nCol,pSample->anLt,0,0); - decodeIntArray((char*)sqlite3_column_text(pStmt,3),nCol,pSample->anDLt,0,0); - - /* Take a copy of the sample. Add two 0x00 bytes the end of the buffer. - ** This is in case the sample record is corrupted. In that case, the - ** sqlite3VdbeRecordCompare() may read up to two varints past the - ** end of the allocated buffer before it realizes it is dealing with - ** a corrupt record. Adding the two 0x00 bytes prevents this from causing - ** a buffer overread. */ - pSample->n = sqlite3_column_bytes(pStmt, 4); - pSample->p = sqlite3DbMallocZero(db, pSample->n + 2); - if( pSample->p==0 ){ - sqlite3_finalize(pStmt); - return SQLITE_NOMEM; - } - memcpy(pSample->p, sqlite3_column_blob(pStmt, 4), pSample->n); - pIdx->nSample++; - } - rc = sqlite3_finalize(pStmt); - if( rc==SQLITE_OK ) initAvgEq(pPrevIdx); - return rc; -} - -/* -** Load content from the sqlite_stat4 and sqlite_stat3 tables into -** the Index.aSample[] arrays of all indices. -*/ -static int loadStat4(sqlite3 *db, const char *zDb){ - int rc = SQLITE_OK; /* Result codes from subroutines */ - - assert( db->lookaside.bEnabled==0 ); - if( sqlite3FindTable(db, "sqlite_stat4", zDb) ){ - rc = loadStatTbl(db, 0, - "SELECT idx,count(*) FROM %Q.sqlite_stat4 GROUP BY idx", - "SELECT idx,neq,nlt,ndlt,sample FROM %Q.sqlite_stat4", - zDb - ); - } - - if( rc==SQLITE_OK && sqlite3FindTable(db, "sqlite_stat3", zDb) ){ - rc = loadStatTbl(db, 1, - "SELECT idx,count(*) FROM %Q.sqlite_stat3 GROUP BY idx", - "SELECT idx,neq,nlt,ndlt,sqlite_record(sample) FROM %Q.sqlite_stat3", - zDb - ); - } - - return rc; -} -#endif /* SQLITE_ENABLE_STAT3_OR_STAT4 */ - -/* -** Load the content of the sqlite_stat1 and sqlite_stat3/4 tables. The -** contents of sqlite_stat1 are used to populate the Index.aiRowEst[] -** arrays. The contents of sqlite_stat3/4 are used to populate the -** Index.aSample[] arrays. -** -** If the sqlite_stat1 table is not present in the database, SQLITE_ERROR -** is returned. In this case, even if SQLITE_ENABLE_STAT3/4 was defined -** during compilation and the sqlite_stat3/4 table is present, no data is -** read from it. -** -** If SQLITE_ENABLE_STAT3/4 was defined during compilation and the -** sqlite_stat4 table is not present in the database, SQLITE_ERROR is -** returned. However, in this case, data is read from the sqlite_stat1 -** table (if it is present) before returning. -** -** If an OOM error occurs, this function always sets db->mallocFailed. -** This means if the caller does not care about other errors, the return -** code may be ignored. -*/ -int sqlite3AnalysisLoad(sqlite3 *db, int iDb){ - analysisInfo sInfo; - HashElem *i; - char *zSql; - int rc; - - assert( iDb>=0 && iDb<db->nDb ); - assert( db->aDb[iDb].pBt!=0 ); - - /* Clear any prior statistics */ - assert( sqlite3SchemaMutexHeld(db, iDb, 0) ); - for(i=sqliteHashFirst(&db->aDb[iDb].pSchema->idxHash);i;i=sqliteHashNext(i)){ - Index *pIdx = sqliteHashData(i); - sqlite3DefaultRowEst(pIdx); -#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 - sqlite3DeleteIndexSamples(db, pIdx); - pIdx->aSample = 0; -#endif - } - - /* Check to make sure the sqlite_stat1 table exists */ - sInfo.db = db; - sInfo.zDatabase = db->aDb[iDb].zName; - if( sqlite3FindTable(db, "sqlite_stat1", sInfo.zDatabase)==0 ){ - return SQLITE_ERROR; - } - - /* Load new statistics out of the sqlite_stat1 table */ - zSql = sqlite3MPrintf(db, - "SELECT tbl,idx,stat FROM %Q.sqlite_stat1", sInfo.zDatabase); - if( zSql==0 ){ - rc = SQLITE_NOMEM; - }else{ - rc = sqlite3_exec(db, zSql, analysisLoader, &sInfo, 0); - sqlite3DbFree(db, zSql); - } - - - /* Load the statistics from the sqlite_stat4 table. */ -#ifdef SQLITE_ENABLE_STAT3_OR_STAT4 - if( rc==SQLITE_OK && OptimizationEnabled(db, SQLITE_Stat34) ){ - int lookasideEnabled = db->lookaside.bEnabled; - db->lookaside.bEnabled = 0; - rc = loadStat4(db, sInfo.zDatabase); - db->lookaside.bEnabled = lookasideEnabled; - } - for(i=sqliteHashFirst(&db->aDb[iDb].pSchema->idxHash);i;i=sqliteHashNext(i)){ - Index *pIdx = sqliteHashData(i); - sqlite3_free(pIdx->aiRowEst); - pIdx->aiRowEst = 0; - } -#endif - - if( rc==SQLITE_NOMEM ){ - db->mallocFailed = 1; - } - return rc; -} - - -#endif /* SQLITE_OMIT_ANALYZE */ |