diff options
Diffstat (limited to 'src/where.c')
| -rw-r--r-- | src/where.c | 62 |
1 files changed, 51 insertions, 11 deletions
diff --git a/src/where.c b/src/where.c index d324228..216a47f 100644 --- a/src/where.c +++ b/src/where.c @@ -3622,7 +3622,7 @@ static int codeAllEqualityTerms( int r1; int k = pIdx->aiColumn[j]; pTerm = findTerm(pWC, iCur, k, notReady, pLevel->plan.wsFlags, pIdx); - if( NEVER(pTerm==0) ) break; + if( pTerm==0 ) break; /* The following true for indices with redundant columns. ** Ex: CREATE INDEX i1 ON t1(a,b,a); SELECT * FROM t1 WHERE a=0 AND b=0; */ testcase( (pTerm->wtFlags & TERM_CODED)!=0 ); @@ -4297,6 +4297,8 @@ static Bitmask codeOneLoopStart( */ WhereClause *pOrWc; /* The OR-clause broken out into subterms */ SrcList *pOrTab; /* Shortened table list or OR-clause generation */ + Index *pCov = 0; /* Potential covering index (or NULL) */ + int iCovCur = pParse->nTab++; /* Cursor used for index scans (if any) */ int regReturn = ++pParse->nMem; /* Register used with OP_Gosub */ int regRowset = 0; /* Register for RowSet object */ @@ -4315,7 +4317,7 @@ static Bitmask codeOneLoopStart( pLevel->op = OP_Return; pLevel->p1 = regReturn; - /* Set up a new SrcList ni pOrTab containing the table being scanned + /* Set up a new SrcList in pOrTab containing the table being scanned ** by this loop in the a[0] slot and all notReady tables in a[1..] slots. ** This becomes the SrcList in the recursive call to sqlite3WhereBegin(). */ @@ -4392,8 +4394,10 @@ static Bitmask codeOneLoopStart( /* Loop through table entries that match term pOrTerm. */ pSubWInfo = sqlite3WhereBegin(pParse, pOrTab, pOrExpr, 0, 0, WHERE_OMIT_OPEN_CLOSE | WHERE_AND_ONLY | - WHERE_FORCE_TABLE | WHERE_ONETABLE_ONLY); + WHERE_FORCE_TABLE | WHERE_ONETABLE_ONLY, iCovCur); + assert( pSubWInfo || pParse->nErr || pParse->db->mallocFailed ); if( pSubWInfo ){ + WhereLevel *pLvl; explainOneScan( pParse, pOrTab, &pSubWInfo->a[0], iLevel, pLevel->iFrom, 0 ); @@ -4414,11 +4418,36 @@ static Bitmask codeOneLoopStart( */ if( pSubWInfo->untestedTerms ) untestedTerms = 1; + /* If all of the OR-connected terms are optimized using the same + ** index, and the index is opened using the same cursor number + ** by each call to sqlite3WhereBegin() made by this loop, it may + ** be possible to use that index as a covering index. + ** + ** If the call to sqlite3WhereBegin() above resulted in a scan that + ** uses an index, and this is either the first OR-connected term + ** processed or the index is the same as that used by all previous + ** terms, set pCov to the candidate covering index. Otherwise, set + ** pCov to NULL to indicate that no candidate covering index will + ** be available. + */ + pLvl = &pSubWInfo->a[0]; + if( (pLvl->plan.wsFlags & WHERE_INDEXED)!=0 + && (pLvl->plan.wsFlags & WHERE_TEMP_INDEX)==0 + && (ii==0 || pLvl->plan.u.pIdx==pCov) + ){ + assert( pLvl->iIdxCur==iCovCur ); + pCov = pLvl->plan.u.pIdx; + }else{ + pCov = 0; + } + /* Finish the loop through table entries that match term pOrTerm. */ sqlite3WhereEnd(pSubWInfo); } } } + pLevel->u.pCovidx = pCov; + if( pCov ) pLevel->iIdxCur = iCovCur; if( pAndExpr ){ pAndExpr->pLeft = 0; sqlite3ExprDelete(pParse->db, pAndExpr); @@ -4636,7 +4665,8 @@ WhereInfo *sqlite3WhereBegin( Expr *pWhere, /* The WHERE clause */ ExprList **ppOrderBy, /* An ORDER BY clause, or NULL */ ExprList *pDistinct, /* The select-list for DISTINCT queries - or NULL */ - u16 wctrlFlags /* One of the WHERE_* flags defined in sqliteInt.h */ + u16 wctrlFlags, /* One of the WHERE_* flags defined in sqliteInt.h */ + int iIdxCur /* If WHERE_ONETABLE_ONLY is set, index cursor number */ ){ int i; /* Loop counter */ int nByteWInfo; /* Num. bytes allocated for WhereInfo struct */ @@ -4956,7 +4986,13 @@ WhereInfo *sqlite3WhereBegin( testcase( bestPlan.plan.wsFlags & WHERE_INDEXED ); testcase( bestPlan.plan.wsFlags & WHERE_TEMP_INDEX ); if( bestPlan.plan.wsFlags & (WHERE_INDEXED|WHERE_TEMP_INDEX) ){ - pLevel->iIdxCur = pParse->nTab++; + if( (wctrlFlags & WHERE_ONETABLE_ONLY) + && (bestPlan.plan.wsFlags & WHERE_TEMP_INDEX)==0 + ){ + pLevel->iIdxCur = iIdxCur; + }else{ + pLevel->iIdxCur = pParse->nTab++; + } }else{ pLevel->iIdxCur = -1; } @@ -5057,10 +5093,10 @@ WhereInfo *sqlite3WhereBegin( if( (pLevel->plan.wsFlags & WHERE_INDEXED)!=0 ){ Index *pIx = pLevel->plan.u.pIdx; KeyInfo *pKey = sqlite3IndexKeyinfo(pParse, pIx); - int iIdxCur = pLevel->iIdxCur; + int iIndexCur = pLevel->iIdxCur; assert( pIx->pSchema==pTab->pSchema ); - assert( iIdxCur>=0 ); - sqlite3VdbeAddOp4(v, OP_OpenRead, iIdxCur, pIx->tnum, iDb, + assert( iIndexCur>=0 ); + sqlite3VdbeAddOp4(v, OP_OpenRead, iIndexCur, pIx->tnum, iDb, (char*)pKey, P4_KEYINFO_HANDOFF); VdbeComment((v, "%s", pIx->zName)); } @@ -5208,6 +5244,7 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){ */ assert( pWInfo->nLevel==1 || pWInfo->nLevel==pTabList->nSrc ); for(i=0, pLevel=pWInfo->a; i<pWInfo->nLevel; i++, pLevel++){ + Index *pIdx = 0; struct SrcList_item *pTabItem = &pTabList->a[pLevel->iFrom]; Table *pTab = pTabItem->pTab; assert( pTab!=0 ); @@ -5237,12 +5274,15 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){ ** that reference the table and converts them into opcodes that ** reference the index. */ - if( (pLevel->plan.wsFlags & WHERE_INDEXED)!=0 && !db->mallocFailed){ + if( pLevel->plan.wsFlags & WHERE_INDEXED ){ + pIdx = pLevel->plan.u.pIdx; + }else if( pLevel->plan.wsFlags & WHERE_MULTI_OR ){ + pIdx = pLevel->u.pCovidx; + } + if( pIdx && !db->mallocFailed){ int k, j, last; VdbeOp *pOp; - Index *pIdx = pLevel->plan.u.pIdx; - assert( pIdx!=0 ); pOp = sqlite3VdbeGetOp(v, pWInfo->iTop); last = sqlite3VdbeCurrentAddr(v); for(k=pWInfo->iTop; k<last; k++, pOp++){ |