diff options
Diffstat (limited to 'lib/libsqlite3/src/select.c')
| -rw-r--r-- | lib/libsqlite3/src/select.c | 351 |
1 files changed, 224 insertions, 127 deletions
diff --git a/lib/libsqlite3/src/select.c b/lib/libsqlite3/src/select.c index 850bc6a9026..932874d8fe7 100644 --- a/lib/libsqlite3/src/select.c +++ b/lib/libsqlite3/src/select.c @@ -14,6 +14,34 @@ */ #include "sqliteInt.h" +/* +** An instance of the following object is used to record information about +** how to process the DISTINCT keyword, to simplify passing that information +** into the selectInnerLoop() routine. +*/ +typedef struct DistinctCtx DistinctCtx; +struct DistinctCtx { + u8 isTnct; /* True if the DISTINCT keyword is present */ + u8 eTnctType; /* One of the WHERE_DISTINCT_* operators */ + int tabTnct; /* Ephemeral table used for DISTINCT processing */ + int addrTnct; /* Address of OP_OpenEphemeral opcode for tabTnct */ +}; + +/* +** An instance of the following object is used to record information about +** the ORDER BY (or GROUP BY) clause of query is being coded. +*/ +typedef struct SortCtx SortCtx; +struct SortCtx { + ExprList *pOrderBy; /* The ORDER BY (or GROUP BY clause) */ + int nOBSat; /* Number of ORDER BY terms satisfied by indices */ + int iECursor; /* Cursor number for the sorter */ + int regReturn; /* Register holding block-output return address */ + int labelBkOut; /* Start label for the block-output subroutine */ + int addrSortIndex; /* Address of the OP_SorterOpen or OP_OpenEphemeral */ + u8 sortFlags; /* Zero or more SORTFLAG_* bits */ +}; +#define SORTFLAG_UseSorter 0x01 /* Use SorterOpen instead of OpenEphemeral */ /* ** Delete all the content of a Select structure but do not deallocate @@ -87,7 +115,6 @@ Select *sqlite3SelectNew( assert( pOffset==0 || pLimit!=0 ); pNew->addrOpenEphm[0] = -1; pNew->addrOpenEphm[1] = -1; - pNew->addrOpenEphm[2] = -1; if( db->mallocFailed ) { clearSelect(db, pNew); if( pNew!=&standin ) sqlite3DbFree(db, pNew); @@ -419,34 +446,73 @@ static int sqliteProcessJoin(Parse *pParse, Select *p){ return 0; } +/* Forward reference */ +static KeyInfo *keyInfoFromExprList( + Parse *pParse, /* Parsing context */ + ExprList *pList, /* Form the KeyInfo object from this ExprList */ + int iStart, /* Begin with this column of pList */ + int nExtra /* Add this many extra columns to the end */ +); + /* -** Insert code into "v" that will push the record on the top of the -** stack into the sorter. +** Insert code into "v" that will push the record in register regData +** into the sorter. */ static void pushOntoSorter( Parse *pParse, /* Parser context */ - ExprList *pOrderBy, /* The ORDER BY clause */ + SortCtx *pSort, /* Information about the ORDER BY clause */ Select *pSelect, /* The whole SELECT statement */ int regData /* Register holding data to be sorted */ ){ Vdbe *v = pParse->pVdbe; - int nExpr = pOrderBy->nExpr; - int regBase = sqlite3GetTempRange(pParse, nExpr+2); - int regRecord = sqlite3GetTempReg(pParse); + int nExpr = pSort->pOrderBy->nExpr; + int regRecord = ++pParse->nMem; + int regBase = pParse->nMem+1; + int nOBSat = pSort->nOBSat; int op; + + pParse->nMem += nExpr+2; /* nExpr+2 registers allocated at regBase */ sqlite3ExprCacheClear(pParse); - sqlite3ExprCodeExprList(pParse, pOrderBy, regBase, 0); - sqlite3VdbeAddOp2(v, OP_Sequence, pOrderBy->iECursor, regBase+nExpr); + sqlite3ExprCodeExprList(pParse, pSort->pOrderBy, regBase, 0); + sqlite3VdbeAddOp2(v, OP_Sequence, pSort->iECursor, regBase+nExpr); sqlite3ExprCodeMove(pParse, regData, regBase+nExpr+1, 1); - sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nExpr + 2, regRecord); - if( pSelect->selFlags & SF_UseSorter ){ + sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase+nOBSat, nExpr+2-nOBSat,regRecord); + if( nOBSat>0 ){ + int regPrevKey; /* The first nOBSat columns of the previous row */ + int addrFirst; /* Address of the OP_IfNot opcode */ + int addrJmp; /* Address of the OP_Jump opcode */ + VdbeOp *pOp; /* Opcode that opens the sorter */ + int nKey; /* Number of sorting key columns, including OP_Sequence */ + KeyInfo *pKI; /* Original KeyInfo on the sorter table */ + + regPrevKey = pParse->nMem+1; + pParse->nMem += pSort->nOBSat; + nKey = nExpr - pSort->nOBSat + 1; + addrFirst = sqlite3VdbeAddOp1(v, OP_IfNot, regBase+nExpr); VdbeCoverage(v); + sqlite3VdbeAddOp3(v, OP_Compare, regPrevKey, regBase, pSort->nOBSat); + pOp = sqlite3VdbeGetOp(v, pSort->addrSortIndex); + if( pParse->db->mallocFailed ) return; + pOp->p2 = nKey + 1; + pKI = pOp->p4.pKeyInfo; + memset(pKI->aSortOrder, 0, pKI->nField); /* Makes OP_Jump below testable */ + sqlite3VdbeChangeP4(v, -1, (char*)pKI, P4_KEYINFO); + pOp->p4.pKeyInfo = keyInfoFromExprList(pParse, pSort->pOrderBy, nOBSat, 1); + addrJmp = sqlite3VdbeCurrentAddr(v); + sqlite3VdbeAddOp3(v, OP_Jump, addrJmp+1, 0, addrJmp+1); VdbeCoverage(v); + pSort->labelBkOut = sqlite3VdbeMakeLabel(v); + pSort->regReturn = ++pParse->nMem; + sqlite3VdbeAddOp2(v, OP_Gosub, pSort->regReturn, pSort->labelBkOut); + sqlite3VdbeAddOp1(v, OP_ResetSorter, pSort->iECursor); + sqlite3VdbeJumpHere(v, addrFirst); + sqlite3VdbeAddOp3(v, OP_Move, regBase, regPrevKey, pSort->nOBSat); + sqlite3VdbeJumpHere(v, addrJmp); + } + if( pSort->sortFlags & SORTFLAG_UseSorter ){ op = OP_SorterInsert; }else{ op = OP_IdxInsert; } - sqlite3VdbeAddOp2(v, op, pOrderBy->iECursor, regRecord); - sqlite3ReleaseTempReg(pParse, regRecord); - sqlite3ReleaseTempRange(pParse, regBase, nExpr+2); + sqlite3VdbeAddOp2(v, op, pSort->iECursor, regRecord); if( pSelect->iLimit ){ int addr1, addr2; int iLimit; @@ -459,8 +525,8 @@ static void pushOntoSorter( sqlite3VdbeAddOp2(v, OP_AddImm, iLimit, -1); addr2 = sqlite3VdbeAddOp0(v, OP_Goto); sqlite3VdbeJumpHere(v, addr1); - sqlite3VdbeAddOp1(v, OP_Last, pOrderBy->iECursor); - sqlite3VdbeAddOp1(v, OP_Delete, pOrderBy->iECursor); + sqlite3VdbeAddOp1(v, OP_Last, pSort->iECursor); + sqlite3VdbeAddOp1(v, OP_Delete, pSort->iECursor); sqlite3VdbeJumpHere(v, addr2); } } @@ -473,10 +539,9 @@ static void codeOffset( int iOffset, /* Register holding the offset counter */ int iContinue /* Jump here to skip the current record */ ){ - if( iOffset>0 && iContinue!=0 ){ + if( iOffset>0 ){ int addr; - sqlite3VdbeAddOp2(v, OP_AddImm, iOffset, -1); - addr = sqlite3VdbeAddOp1(v, OP_IfNeg, iOffset); VdbeCoverage(v); + addr = sqlite3VdbeAddOp3(v, OP_IfNeg, iOffset, 0, -1); VdbeCoverage(v); sqlite3VdbeAddOp2(v, OP_Goto, 0, iContinue); VdbeComment((v, "skip OFFSET records")); sqlite3VdbeJumpHere(v, addr); @@ -535,19 +600,6 @@ static int checkForMultiColumnSelectError( #endif /* -** An instance of the following object is used to record information about -** how to process the DISTINCT keyword, to simplify passing that information -** into the selectInnerLoop() routine. -*/ -typedef struct DistinctCtx DistinctCtx; -struct DistinctCtx { - u8 isTnct; /* True if the DISTINCT keyword is present */ - u8 eTnctType; /* One of the WHERE_DISTINCT_* operators */ - int tabTnct; /* Ephemeral table used for DISTINCT processing */ - int addrTnct; /* Address of OP_OpenEphemeral opcode for tabTnct */ -}; - -/* ** This routine generates the code for the inside of the inner loop ** of a SELECT. ** @@ -561,7 +613,7 @@ static void selectInnerLoop( Select *p, /* The complete select statement being coded */ ExprList *pEList, /* List of values being extracted */ int srcTab, /* Pull data from this table */ - ExprList *pOrderBy, /* If not NULL, sort results using this key */ + SortCtx *pSort, /* If not NULL, info on how to process ORDER BY */ DistinctCtx *pDistinct, /* If not NULL, info on how to process DISTINCT */ SelectDest *pDest, /* How to dispose of the results */ int iContinue, /* Jump here to continue with next row */ @@ -578,7 +630,9 @@ static void selectInnerLoop( assert( v ); assert( pEList!=0 ); hasDistinct = pDistinct ? pDistinct->eTnctType : WHERE_DISTINCT_NOOP; - if( pOrderBy==0 && !hasDistinct ){ + if( pSort && pSort->pOrderBy==0 ) pSort = 0; + if( pSort==0 && !hasDistinct ){ + assert( iContinue!=0 ); codeOffset(v, p->iOffset, iContinue); } @@ -652,7 +706,7 @@ static void selectInnerLoop( sqlite3VdbeChangeP4(v, -1, (const char *)pColl, P4_COLLSEQ); sqlite3VdbeChangeP5(v, SQLITE_NULLEQ); } - assert( sqlite3VdbeCurrentAddr(v)==iJump ); + assert( sqlite3VdbeCurrentAddr(v)==iJump || pParse->db->mallocFailed ); sqlite3VdbeAddOp3(v, OP_Copy, regResult, regPrev, nResultCol-1); break; } @@ -668,7 +722,7 @@ static void selectInnerLoop( break; } } - if( pOrderBy==0 ){ + if( pSort==0 ){ codeOffset(v, p->iOffset, iContinue); } } @@ -699,7 +753,8 @@ static void selectInnerLoop( /* Store the result as data using a unique key. */ - case SRT_DistTable: + case SRT_Fifo: + case SRT_DistFifo: case SRT_Table: case SRT_EphemTab: { int r1 = sqlite3GetTempReg(pParse); @@ -707,8 +762,8 @@ static void selectInnerLoop( testcase( eDest==SRT_EphemTab ); sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nResultCol, r1); #ifndef SQLITE_OMIT_CTE - if( eDest==SRT_DistTable ){ - /* If the destination is DistTable, then cursor (iParm+1) is open + if( eDest==SRT_DistFifo ){ + /* If the destination is DistFifo, then cursor (iParm+1) is open ** on an ephemeral index. If the current row is already present ** in the index, do not write it to the output. If not, add the ** current row to the index and proceed with writing it to the @@ -716,11 +771,11 @@ static void selectInnerLoop( int addr = sqlite3VdbeCurrentAddr(v) + 4; sqlite3VdbeAddOp4Int(v, OP_Found, iParm+1, addr, r1, 0); VdbeCoverage(v); sqlite3VdbeAddOp2(v, OP_IdxInsert, iParm+1, r1); - assert( pOrderBy==0 ); + assert( pSort==0 ); } #endif - if( pOrderBy ){ - pushOntoSorter(pParse, pOrderBy, p, r1); + if( pSort ){ + pushOntoSorter(pParse, pSort, p, r1); }else{ int r2 = sqlite3GetTempReg(pParse); sqlite3VdbeAddOp2(v, OP_NewRowid, iParm, r2); @@ -741,12 +796,12 @@ static void selectInnerLoop( assert( nResultCol==1 ); pDest->affSdst = sqlite3CompareAffinity(pEList->a[0].pExpr, pDest->affSdst); - if( pOrderBy ){ + if( pSort ){ /* At first glance you would think we could optimize out the ** ORDER BY in this case since the order of entries in the set ** does not matter. But there might be a LIMIT clause, in which ** case the order does matter */ - pushOntoSorter(pParse, pOrderBy, p, regResult); + pushOntoSorter(pParse, pSort, p, regResult); }else{ int r1 = sqlite3GetTempReg(pParse); sqlite3VdbeAddOp4(v, OP_MakeRecord, regResult,1,r1, &pDest->affSdst, 1); @@ -771,8 +826,8 @@ static void selectInnerLoop( */ case SRT_Mem: { assert( nResultCol==1 ); - if( pOrderBy ){ - pushOntoSorter(pParse, pOrderBy, p, regResult); + if( pSort ){ + pushOntoSorter(pParse, pSort, p, regResult); }else{ sqlite3ExprCodeMove(pParse, regResult, iParm, 1); /* The LIMIT clause will jump out of the loop for us */ @@ -785,10 +840,10 @@ static void selectInnerLoop( case SRT_Output: { /* Return the results */ testcase( eDest==SRT_Coroutine ); testcase( eDest==SRT_Output ); - if( pOrderBy ){ + if( pSort ){ int r1 = sqlite3GetTempReg(pParse); sqlite3VdbeAddOp3(v, OP_MakeRecord, regResult, nResultCol, r1); - pushOntoSorter(pParse, pOrderBy, p, r1); + pushOntoSorter(pParse, pSort, p, r1); sqlite3ReleaseTempReg(pParse, r1); }else if( eDest==SRT_Coroutine ){ sqlite3VdbeAddOp1(v, OP_Yield, pDest->iSDParm); @@ -865,7 +920,7 @@ static void selectInnerLoop( ** there is a sorter, in which case the sorter has already limited ** the output for us. */ - if( pOrderBy==0 && p->iLimit ){ + if( pSort==0 && p->iLimit ){ sqlite3VdbeAddOp3(v, OP_IfZero, p->iLimit, iBreak, -1); VdbeCoverage(v); } } @@ -936,7 +991,12 @@ int sqlite3KeyInfoIsWriteable(KeyInfo *p){ return p->nRef==1; } ** function is responsible for seeing that this structure is eventually ** freed. */ -static KeyInfo *keyInfoFromExprList(Parse *pParse, ExprList *pList, int nExtra){ +static KeyInfo *keyInfoFromExprList( + Parse *pParse, /* Parsing context */ + ExprList *pList, /* Form the KeyInfo object from this ExprList */ + int iStart, /* Begin with this column of pList */ + int nExtra /* Add this many extra columns to the end */ +){ int nExpr; KeyInfo *pInfo; struct ExprList_item *pItem; @@ -944,15 +1004,15 @@ static KeyInfo *keyInfoFromExprList(Parse *pParse, ExprList *pList, int nExtra){ int i; nExpr = pList->nExpr; - pInfo = sqlite3KeyInfoAlloc(db, nExpr+nExtra, 1); + pInfo = sqlite3KeyInfoAlloc(db, nExpr+nExtra-iStart, 1); if( pInfo ){ assert( sqlite3KeyInfoIsWriteable(pInfo) ); - for(i=0, pItem=pList->a; i<nExpr; i++, pItem++){ + for(i=iStart, pItem=pList->a+iStart; i<nExpr; i++, pItem++){ CollSeq *pColl; pColl = sqlite3ExprCollSeq(pParse, pItem->pExpr); if( !pColl ) pColl = db->pDfltColl; - pInfo->aColl[i] = pColl; - pInfo->aSortOrder[i] = pItem->sortOrder; + pInfo->aColl[i-iStart] = pColl; + pInfo->aSortOrder[i-iStart] = pItem->sortOrder; } } return pInfo; @@ -1054,24 +1114,31 @@ static void explainComposite( static void generateSortTail( Parse *pParse, /* Parsing context */ Select *p, /* The SELECT statement */ - Vdbe *v, /* Generate code into this VDBE */ + SortCtx *pSort, /* Information on the ORDER BY clause */ int nColumn, /* Number of columns of data */ SelectDest *pDest /* Write the sorted results here */ ){ + Vdbe *v = pParse->pVdbe; /* The prepared statement */ int addrBreak = sqlite3VdbeMakeLabel(v); /* Jump here to exit loop */ int addrContinue = sqlite3VdbeMakeLabel(v); /* Jump here for next cycle */ int addr; + int addrOnce = 0; int iTab; int pseudoTab = 0; - ExprList *pOrderBy = p->pOrderBy; - + ExprList *pOrderBy = pSort->pOrderBy; int eDest = pDest->eDest; int iParm = pDest->iSDParm; - int regRow; int regRowid; + int nKey; - iTab = pOrderBy->iECursor; + if( pSort->labelBkOut ){ + sqlite3VdbeAddOp2(v, OP_Gosub, pSort->regReturn, pSort->labelBkOut); + sqlite3VdbeAddOp2(v, OP_Goto, 0, addrBreak); + sqlite3VdbeResolveLabel(v, pSort->labelBkOut); + addrOnce = sqlite3CodeOnce(pParse); VdbeCoverage(v); + } + iTab = pSort->iECursor; regRow = sqlite3GetTempReg(pParse); if( eDest==SRT_Output || eDest==SRT_Coroutine ){ pseudoTab = pParse->nTab++; @@ -1080,20 +1147,23 @@ static void generateSortTail( }else{ regRowid = sqlite3GetTempReg(pParse); } - if( p->selFlags & SF_UseSorter ){ + nKey = pOrderBy->nExpr - pSort->nOBSat; + if( pSort->sortFlags & SORTFLAG_UseSorter ){ int regSortOut = ++pParse->nMem; int ptab2 = pParse->nTab++; - sqlite3VdbeAddOp3(v, OP_OpenPseudo, ptab2, regSortOut, pOrderBy->nExpr+2); + sqlite3VdbeAddOp3(v, OP_OpenPseudo, ptab2, regSortOut, nKey+2); + if( addrOnce ) sqlite3VdbeJumpHere(v, addrOnce); addr = 1 + sqlite3VdbeAddOp2(v, OP_SorterSort, iTab, addrBreak); VdbeCoverage(v); codeOffset(v, p->iOffset, addrContinue); sqlite3VdbeAddOp2(v, OP_SorterData, iTab, regSortOut); - sqlite3VdbeAddOp3(v, OP_Column, ptab2, pOrderBy->nExpr+1, regRow); + sqlite3VdbeAddOp3(v, OP_Column, ptab2, nKey+1, regRow); sqlite3VdbeChangeP5(v, OPFLAG_CLEARCACHE); }else{ + if( addrOnce ) sqlite3VdbeJumpHere(v, addrOnce); addr = 1 + sqlite3VdbeAddOp2(v, OP_Sort, iTab, addrBreak); VdbeCoverage(v); codeOffset(v, p->iOffset, addrContinue); - sqlite3VdbeAddOp3(v, OP_Column, iTab, pOrderBy->nExpr+1, regRow); + sqlite3VdbeAddOp3(v, OP_Column, iTab, nKey+1, regRow); } switch( eDest ){ case SRT_Table: @@ -1148,15 +1218,13 @@ static void generateSortTail( /* The bottom of the loop */ sqlite3VdbeResolveLabel(v, addrContinue); - if( p->selFlags & SF_UseSorter ){ + if( pSort->sortFlags & SORTFLAG_UseSorter ){ sqlite3VdbeAddOp2(v, OP_SorterNext, iTab, addr); VdbeCoverage(v); }else{ sqlite3VdbeAddOp2(v, OP_Next, iTab, addr); VdbeCoverage(v); } + if( pSort->regReturn ) sqlite3VdbeAddOp1(v, OP_Return, pSort->regReturn); sqlite3VdbeResolveLabel(v, addrBreak); - if( eDest==SRT_Output || eDest==SRT_Coroutine ){ - sqlite3VdbeAddOp2(v, OP_Close, pseudoTab, 0); - } } /* @@ -1616,7 +1684,7 @@ Table *sqlite3ResultSetOfSelect(Parse *pParse, Select *pSelect){ assert( db->lookaside.bEnabled==0 ); pTab->nRef = 1; pTab->zName = 0; - pTab->nRowEst = 1048576; + pTab->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) ); selectColumnsFromExprList(pParse, pSelect->pEList, &pTab->nCol, &pTab->aCol); selectAddColumnTypeAndCollation(pParse, pTab, pSelect); pTab->iPKey = -1; @@ -1834,7 +1902,7 @@ static void generateWithRecursiveQuery( int regCurrent; /* Register holding Current table */ int iQueue; /* The Queue table */ int iDistinct = 0; /* To ensure unique results if UNION */ - int eDest = SRT_Table; /* How to write to Queue */ + int eDest = SRT_Fifo; /* How to write to Queue */ SelectDest destQueue; /* SelectDest targetting the Queue table */ int i; /* Loop counter */ int rc; /* Result code */ @@ -1866,13 +1934,13 @@ static void generateWithRecursiveQuery( /* Allocate cursors numbers for Queue and Distinct. The cursor number for ** the Distinct table must be exactly one greater than Queue in order - ** for the SRT_DistTable and SRT_DistQueue destinations to work. */ + ** for the SRT_DistFifo and SRT_DistQueue destinations to work. */ iQueue = pParse->nTab++; if( p->op==TK_UNION ){ - eDest = pOrderBy ? SRT_DistQueue : SRT_DistTable; + eDest = pOrderBy ? SRT_DistQueue : SRT_DistFifo; iDistinct = pParse->nTab++; }else{ - eDest = pOrderBy ? SRT_Queue : SRT_Table; + eDest = pOrderBy ? SRT_Queue : SRT_Fifo; } sqlite3SelectDestInit(&destQueue, eDest, iQueue); @@ -1938,6 +2006,7 @@ static void generateWithRecursiveQuery( sqlite3VdbeResolveLabel(v, addrBreak); end_of_recursive_query: + sqlite3ExprListDelete(pParse->db, p->pOrderBy); p->pOrderBy = pOrderBy; p->pLimit = pLimit; p->pOffset = pOffset; @@ -3754,7 +3823,7 @@ static int withExpand( pTab->nRef = 1; pTab->zName = sqlite3DbStrDup(db, pCte->zName); pTab->iPKey = -1; - pTab->nRowEst = 1048576; + pTab->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) ); pTab->tabFlags |= TF_Ephemeral; pFrom->pSelect = sqlite3SelectDup(db, pCte->pSelect, 0); if( db->mallocFailed ) return SQLITE_NOMEM; @@ -3930,7 +3999,7 @@ static int selectExpander(Walker *pWalker, Select *p){ while( pSel->pPrior ){ pSel = pSel->pPrior; } selectColumnsFromExprList(pParse, pSel->pEList, &pTab->nCol, &pTab->aCol); pTab->iPKey = -1; - pTab->nRowEst = 1048576; + pTab->nRowLogEst = 200; assert( 200==sqlite3LogEst(1048576) ); pTab->tabFlags |= TF_Ephemeral; #endif }else{ @@ -4309,7 +4378,7 @@ static void resetAccumulator(Parse *pParse, AggInfo *pAggInfo){ "argument"); pFunc->iDistinct = -1; }else{ - KeyInfo *pKeyInfo = keyInfoFromExprList(pParse, pE->x.pList, 0); + KeyInfo *pKeyInfo = keyInfoFromExprList(pParse, pE->x.pList, 0, 0); sqlite3VdbeAddOp4(v, OP_OpenEphemeral, pFunc->iDistinct, 0, 0, (char*)pKeyInfo, P4_KEYINFO); } @@ -4425,10 +4494,11 @@ static void explainSimpleCount( Index *pIdx /* Index used to optimize scan, or NULL */ ){ if( pParse->explain==2 ){ + int bCover = (pIdx!=0 && (HasRowid(pTab) || !IsPrimaryKeyIndex(pIdx))); char *zEqp = sqlite3MPrintf(pParse->db, "SCAN TABLE %s%s%s", - pTab->zName, - pIdx ? " USING COVERING INDEX " : "", - pIdx ? pIdx->zName : "" + pTab->zName, + bCover ? " USING COVERING INDEX " : "", + bCover ? pIdx->zName : "" ); sqlite3VdbeAddOp4( pParse->pVdbe, OP_Explain, pParse->iSelectId, 0, 0, zEqp, P4_DYNAMIC @@ -4464,12 +4534,11 @@ int sqlite3Select( ExprList *pEList; /* List of columns to extract. */ SrcList *pTabList; /* List of tables to select from */ Expr *pWhere; /* The WHERE clause. May be NULL */ - ExprList *pOrderBy; /* The ORDER BY clause. May be NULL */ ExprList *pGroupBy; /* The GROUP BY clause. May be NULL */ Expr *pHaving; /* The HAVING clause. May be NULL */ int rc = 1; /* Value to return from this function */ - int addrSortIndex; /* Address of an OP_OpenEphemeral instruction */ DistinctCtx sDistinct; /* Info on how to code the DISTINCT keyword */ + SortCtx sSort; /* Info on how to code the ORDER BY clause */ AggInfo sAggInfo; /* Information used by aggregate queries */ int iEnd; /* Address of the end of the query */ sqlite3 *db; /* The database connection */ @@ -4486,9 +4555,15 @@ int sqlite3Select( if( sqlite3AuthCheck(pParse, SQLITE_SELECT, 0, 0, 0) ) return 1; memset(&sAggInfo, 0, sizeof(sAggInfo)); + assert( p->pOrderBy==0 || pDest->eDest!=SRT_DistFifo ); + assert( p->pOrderBy==0 || pDest->eDest!=SRT_Fifo ); + assert( p->pOrderBy==0 || pDest->eDest!=SRT_DistQueue ); + assert( p->pOrderBy==0 || pDest->eDest!=SRT_Queue ); if( IgnorableOrderby(pDest) ){ assert(pDest->eDest==SRT_Exists || pDest->eDest==SRT_Union || - pDest->eDest==SRT_Except || pDest->eDest==SRT_Discard); + pDest->eDest==SRT_Except || pDest->eDest==SRT_Discard || + pDest->eDest==SRT_Queue || pDest->eDest==SRT_DistFifo || + pDest->eDest==SRT_DistQueue || pDest->eDest==SRT_Fifo); /* If ORDER BY makes no difference in the output then neither does ** DISTINCT so it can be removed too. */ sqlite3ExprListDelete(db, p->pOrderBy); @@ -4496,7 +4571,8 @@ int sqlite3Select( p->selFlags &= ~SF_Distinct; } sqlite3SelectPrep(pParse, p, 0); - pOrderBy = p->pOrderBy; + memset(&sSort, 0, sizeof(sSort)); + sSort.pOrderBy = p->pOrderBy; pTabList = p->pSrc; pEList = p->pEList; if( pParse->nErr || db->mallocFailed ){ @@ -4574,7 +4650,7 @@ int sqlite3Select( sqlite3SelectDestInit(&dest, SRT_Coroutine, pItem->regReturn); explainSetInteger(pItem->iSelectId, (u8)pParse->iNextSelectId); sqlite3Select(pParse, pSub, &dest); - pItem->pTab->nRowEst = (unsigned)pSub->nSelectRow; + pItem->pTab->nRowLogEst = sqlite3LogEst(pSub->nSelectRow); pItem->viaCoroutine = 1; pItem->regResult = dest.iSdst; sqlite3VdbeAddOp1(v, OP_EndCoroutine, pItem->regReturn); @@ -4605,7 +4681,7 @@ int sqlite3Select( sqlite3SelectDestInit(&dest, SRT_EphemTab, pItem->iCursor); explainSetInteger(pItem->iSelectId, (u8)pParse->iNextSelectId); sqlite3Select(pParse, pSub, &dest); - pItem->pTab->nRowEst = (unsigned)pSub->nSelectRow; + pItem->pTab->nRowLogEst = sqlite3LogEst(pSub->nSelectRow); if( onceAddr ) sqlite3VdbeJumpHere(v, onceAddr); retAddr = sqlite3VdbeAddOp1(v, OP_Return, pItem->regReturn); VdbeComment((v, "end %s", pItem->pTab->zName)); @@ -4618,7 +4694,7 @@ int sqlite3Select( pParse->nHeight -= sqlite3SelectExprHeight(p); pTabList = p->pSrc; if( !IgnorableOrderby(pDest) ){ - pOrderBy = p->pOrderBy; + sSort.pOrderBy = p->pOrderBy; } } pEList = p->pEList; @@ -4638,18 +4714,6 @@ int sqlite3Select( } #endif - /* If there is both a GROUP BY and an ORDER BY clause and they are - ** identical, then disable the ORDER BY clause since the GROUP BY - ** will cause elements to come out in the correct order. This is - ** an optimization - the correct answer should result regardless. - ** Use the SQLITE_GroupByOrder flag with SQLITE_TESTCTRL_OPTIMIZER - ** to disable this optimization for testing purposes. - */ - if( sqlite3ExprListCompare(p->pGroupBy, pOrderBy, -1)==0 - && OptimizationEnabled(db, SQLITE_GroupByOrder) ){ - pOrderBy = 0; - } - /* If the query is DISTINCT with an ORDER BY but is not an aggregate, and ** if the select-list is the same as the ORDER BY list, then this query ** can be rewritten as a GROUP BY. In other words, this: @@ -4666,12 +4730,12 @@ 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, -1)==0 + && sqlite3ExprListCompare(sSort.pOrderBy, p->pEList, -1)==0 ){ p->selFlags &= ~SF_Distinct; p->pGroupBy = sqlite3ExprListDup(db, p->pEList, 0); pGroupBy = p->pGroupBy; - pOrderBy = 0; + sSort.pOrderBy = 0; /* Notice that even thought SF_Distinct has been cleared from p->selFlags, ** the sDistinct.isTnct is still set. Hence, isTnct represents the ** original setting of the SF_Distinct flag, not the current setting */ @@ -4685,16 +4749,16 @@ int sqlite3Select( ** we figure out that the sorting index is not needed. The addrSortIndex ** variable is used to facilitate that change. */ - if( pOrderBy ){ + if( sSort.pOrderBy ){ KeyInfo *pKeyInfo; - pKeyInfo = keyInfoFromExprList(pParse, pOrderBy, 0); - pOrderBy->iECursor = pParse->nTab++; - p->addrOpenEphm[2] = addrSortIndex = + pKeyInfo = keyInfoFromExprList(pParse, sSort.pOrderBy, 0, 0); + sSort.iECursor = pParse->nTab++; + sSort.addrSortIndex = sqlite3VdbeAddOp4(v, OP_OpenEphemeral, - pOrderBy->iECursor, pOrderBy->nExpr+2, 0, + sSort.iECursor, sSort.pOrderBy->nExpr+2, 0, (char*)pKeyInfo, P4_KEYINFO); }else{ - addrSortIndex = -1; + sSort.addrSortIndex = -1; } /* If the output is destined for a temporary table, open that table. @@ -4708,9 +4772,9 @@ int sqlite3Select( iEnd = sqlite3VdbeMakeLabel(v); p->nSelectRow = LARGEST_INT64; computeLimitRegisters(pParse, p, iEnd); - if( p->iLimit==0 && addrSortIndex>=0 ){ - sqlite3VdbeGetOp(v, addrSortIndex)->opcode = OP_SorterOpen; - p->selFlags |= SF_UseSorter; + if( p->iLimit==0 && sSort.addrSortIndex>=0 ){ + sqlite3VdbeGetOp(v, sSort.addrSortIndex)->opcode = OP_SorterOpen; + sSort.sortFlags |= SORTFLAG_UseSorter; } /* Open a virtual index to use for the distinct set. @@ -4719,7 +4783,7 @@ int sqlite3Select( sDistinct.tabTnct = pParse->nTab++; sDistinct.addrTnct = sqlite3VdbeAddOp4(v, OP_OpenEphemeral, sDistinct.tabTnct, 0, 0, - (char*)keyInfoFromExprList(pParse, p->pEList, 0), + (char*)keyInfoFromExprList(pParse, p->pEList,0,0), P4_KEYINFO); sqlite3VdbeChangeP5(v, BTREE_UNORDERED); sDistinct.eTnctType = WHERE_DISTINCT_UNORDERED; @@ -4732,8 +4796,8 @@ int sqlite3Select( u16 wctrlFlags = (sDistinct.isTnct ? WHERE_WANT_DISTINCT : 0); /* Begin the database scan. */ - pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pOrderBy, p->pEList, - wctrlFlags, 0); + pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, sSort.pOrderBy, + p->pEList, wctrlFlags, 0); if( pWInfo==0 ) goto select_end; if( sqlite3WhereOutputRowCount(pWInfo) < p->nSelectRow ){ p->nSelectRow = sqlite3WhereOutputRowCount(pWInfo); @@ -4741,19 +4805,23 @@ int sqlite3Select( if( sDistinct.isTnct && sqlite3WhereIsDistinct(pWInfo) ){ sDistinct.eTnctType = sqlite3WhereIsDistinct(pWInfo); } - if( pOrderBy && sqlite3WhereIsOrdered(pWInfo) ) pOrderBy = 0; + if( sSort.pOrderBy ){ + sSort.nOBSat = sqlite3WhereIsOrdered(pWInfo); + if( sSort.nOBSat==sSort.pOrderBy->nExpr ){ + sSort.pOrderBy = 0; + } + } /* If sorting index that was created by a prior OP_OpenEphemeral ** instruction ended up not being needed, then change the OP_OpenEphemeral ** into an OP_Noop. */ - if( addrSortIndex>=0 && pOrderBy==0 ){ - sqlite3VdbeChangeToNoop(v, addrSortIndex); - p->addrOpenEphm[2] = -1; + if( sSort.addrSortIndex>=0 && sSort.pOrderBy==0 ){ + sqlite3VdbeChangeToNoop(v, sSort.addrSortIndex); } /* Use the standard inner loop. */ - selectInnerLoop(pParse, p, pEList, -1, pOrderBy, &sDistinct, pDest, + selectInnerLoop(pParse, p, pEList, -1, &sSort, &sDistinct, pDest, sqlite3WhereContinueLabel(pWInfo), sqlite3WhereBreakLabel(pWInfo)); @@ -4774,6 +4842,7 @@ int sqlite3Select( int addrEnd; /* End of processing for this SELECT */ int sortPTab = 0; /* Pseudotable used to decode sorting results */ int sortOut = 0; /* Output register from the sorter */ + int orderByGrp = 0; /* True if the GROUP BY and ORDER BY are the same */ /* Remove any and all aliases between the result set and the ** GROUP BY clause. @@ -4793,6 +4862,18 @@ int sqlite3Select( p->nSelectRow = 1; } + + /* If there is both a GROUP BY and an ORDER BY clause and they are + ** identical, then it may be possible to disable the ORDER BY clause + ** on the grounds that the GROUP BY will cause elements to come out + ** in the correct order. It also may not - the GROUP BY may use a + ** database index that causes rows to be grouped together as required + ** but not actually sorted. Either way, record the fact that the + ** ORDER BY and GROUP BY clauses are the same by setting the orderByGrp + ** variable. */ + if( sqlite3ExprListCompare(pGroupBy, sSort.pOrderBy, -1)==0 ){ + orderByGrp = 1; + } /* Create a label to jump to when we want to abort the query */ addrEnd = sqlite3VdbeMakeLabel(v); @@ -4809,7 +4890,7 @@ int sqlite3Select( sAggInfo.nSortingColumn = pGroupBy ? pGroupBy->nExpr+1 : 0; sAggInfo.pGroupBy = pGroupBy; sqlite3ExprAnalyzeAggList(&sNC, pEList); - sqlite3ExprAnalyzeAggList(&sNC, pOrderBy); + sqlite3ExprAnalyzeAggList(&sNC, sSort.pOrderBy); if( pHaving ){ sqlite3ExprAnalyzeAggregates(&sNC, pHaving); } @@ -4843,7 +4924,7 @@ int sqlite3Select( ** will be converted into a Noop. */ sAggInfo.sortingIdx = pParse->nTab++; - pKeyInfo = keyInfoFromExprList(pParse, pGroupBy, 0); + pKeyInfo = keyInfoFromExprList(pParse, pGroupBy, 0, 0); addrSortingIdx = sqlite3VdbeAddOp4(v, OP_SorterOpen, sAggInfo.sortingIdx, sAggInfo.nSortingColumn, 0, (char*)pKeyInfo, P4_KEYINFO); @@ -4872,10 +4953,11 @@ int sqlite3Select( ** in the right order to begin with. */ sqlite3VdbeAddOp2(v, OP_Gosub, regReset, addrReset); - pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pGroupBy, 0, - WHERE_GROUPBY, 0); + pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, pGroupBy, 0, + WHERE_GROUPBY | (orderByGrp ? WHERE_SORTBYGROUP : 0), 0 + ); if( pWInfo==0 ) goto select_end; - if( sqlite3WhereIsOrdered(pWInfo) ){ + if( sqlite3WhereIsOrdered(pWInfo)==pGroupBy->nExpr ){ /* 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 @@ -4938,6 +5020,21 @@ int sqlite3Select( VdbeComment((v, "GROUP BY sort")); VdbeCoverage(v); sAggInfo.useSortingIdx = 1; sqlite3ExprCacheClear(pParse); + + } + + /* If the index or temporary table used by the GROUP BY sort + ** will naturally deliver rows in the order required by the ORDER BY + ** clause, cancel the ephemeral table open coded earlier. + ** + ** This is an optimization - the correct answer should result regardless. + ** Use the SQLITE_GroupByOrder flag with SQLITE_TESTCTRL_OPTIMIZER to + ** disable this optimization for testing purposes. */ + if( orderByGrp && OptimizationEnabled(db, SQLITE_GroupByOrder) + && (groupBySort || sqlite3WhereIsSorted(pWInfo)) + ){ + sSort.pOrderBy = 0; + sqlite3VdbeChangeToNoop(v, sSort.addrSortIndex); } /* Evaluate the current GROUP BY terms and store in b0, b1, b2... @@ -5026,7 +5123,7 @@ int sqlite3Select( sqlite3VdbeAddOp1(v, OP_Return, regOutputRow); finalizeAggFunctions(pParse, &sAggInfo); sqlite3ExprIfFalse(pParse, pHaving, addrOutputRow+1, SQLITE_JUMPIFNULL); - selectInnerLoop(pParse, p, p->pEList, -1, pOrderBy, + selectInnerLoop(pParse, p, p->pEList, -1, &sSort, &sDistinct, pDest, addrOutputRow+1, addrSetAbort); sqlite3VdbeAddOp1(v, OP_Return, regOutputRow); @@ -5158,7 +5255,7 @@ int sqlite3Select( } updateAccumulator(pParse, &sAggInfo); assert( pMinMax==0 || pMinMax->nExpr==1 ); - if( sqlite3WhereIsOrdered(pWInfo) ){ + if( sqlite3WhereIsOrdered(pWInfo)>0 ){ sqlite3VdbeAddOp2(v, OP_Goto, 0, sqlite3WhereBreakLabel(pWInfo)); VdbeComment((v, "%s() by index", (flag==WHERE_ORDERBY_MIN?"min":"max"))); @@ -5167,7 +5264,7 @@ int sqlite3Select( finalizeAggFunctions(pParse, &sAggInfo); } - pOrderBy = 0; + sSort.pOrderBy = 0; sqlite3ExprIfFalse(pParse, pHaving, addrEnd, SQLITE_JUMPIFNULL); selectInnerLoop(pParse, p, p->pEList, -1, 0, 0, pDest, addrEnd, addrEnd); @@ -5184,9 +5281,9 @@ int sqlite3Select( /* If there is an ORDER BY clause, then we need to sort the results ** and send them to the callback one by one. */ - if( pOrderBy ){ - explainTempTable(pParse, "ORDER BY"); - generateSortTail(pParse, p, v, pEList->nExpr, pDest); + if( sSort.pOrderBy ){ + explainTempTable(pParse, sSort.nOBSat>0 ? "RIGHT PART OF ORDER BY":"ORDER BY"); + generateSortTail(pParse, p, &sSort, pEList->nExpr, pDest); } /* Jump here to skip this query |