diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/where.c | 154 |
1 files changed, 97 insertions, 57 deletions
diff --git a/src/where.c b/src/where.c index 98369db6d..1be1b20a4 100644 --- a/src/where.c +++ b/src/where.c @@ -253,7 +253,7 @@ struct WhereCost { #define WHERE_COLUMN_NULL 0x00080000 /* x IS NULL */ #define WHERE_INDEXED 0x000f0000 /* Anything that uses an index */ #define WHERE_NOT_FULLSCAN 0x100f3000 /* Does not do a full table scan */ -#define WHERE_IN_ABLE 0x000f1000 /* Able to support an IN operator */ +#define WHERE_IN_ABLE 0x080f1000 /* Able to support an IN operator */ #define WHERE_TOP_LIMIT 0x00100000 /* x<EXPR or x<=EXPR constraint */ #define WHERE_BTM_LIMIT 0x00200000 /* x>EXPR or x>=EXPR constraint */ #define WHERE_BOTH_LIMIT 0x00300000 /* Both x>EXPR and x<EXPR */ @@ -2056,7 +2056,7 @@ static sqlite3_index_info *allocateIndexInfo(WhereBestIdx *p){ assert( (pTerm->eOperator&(pTerm->eOperator-1))==0 ); testcase( pTerm->eOperator==WO_IN ); testcase( pTerm->eOperator==WO_ISNULL ); - if( pTerm->eOperator & (WO_IN|WO_ISNULL) ) continue; + if( pTerm->eOperator & (WO_ISNULL) ) continue; if( pTerm->wtFlags & TERM_VNULL ) continue; nTerm++; } @@ -2104,15 +2104,18 @@ static sqlite3_index_info *allocateIndexInfo(WhereBestIdx *p){ pUsage; for(i=j=0, pTerm=pWC->a; i<pWC->nTerm; i++, pTerm++){ + u8 op; if( pTerm->leftCursor != pSrc->iCursor ) continue; assert( (pTerm->eOperator&(pTerm->eOperator-1))==0 ); testcase( pTerm->eOperator==WO_IN ); testcase( pTerm->eOperator==WO_ISNULL ); - if( pTerm->eOperator & (WO_IN|WO_ISNULL) ) continue; + if( pTerm->eOperator & (WO_ISNULL) ) continue; if( pTerm->wtFlags & TERM_VNULL ) continue; pIdxCons[j].iColumn = pTerm->u.leftColumn; pIdxCons[j].iTermOffset = i; - pIdxCons[j].op = (u8)pTerm->eOperator; + op = (u8)pTerm->eOperator; + if( op==WO_IN ) op = WO_EQ; + pIdxCons[j].op = op; /* The direct assignment in the previous line is possible only because ** the WO_ and SQLITE_INDEX_CONSTRAINT_ codes are identical. The ** following asserts verify this fact. */ @@ -2122,7 +2125,7 @@ static sqlite3_index_info *allocateIndexInfo(WhereBestIdx *p){ assert( WO_GT==SQLITE_INDEX_CONSTRAINT_GT ); assert( WO_GE==SQLITE_INDEX_CONSTRAINT_GE ); assert( WO_MATCH==SQLITE_INDEX_CONSTRAINT_MATCH ); - assert( pTerm->eOperator & (WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE|WO_MATCH) ); + assert( pTerm->eOperator & (WO_IN|WO_EQ|WO_LT|WO_LE|WO_GT|WO_GE|WO_MATCH) ); j++; } for(i=0; i<nOrderBy; i++){ @@ -2208,6 +2211,7 @@ static void bestVirtualIndex(WhereBestIdx *p){ WhereTerm *pTerm; int i, j; int nOrderBy; + int bAllowIN; /* Allow IN optimizations */ double rCost; /* Make sure wsFlags is initialized to some sane value. Otherwise, if the @@ -2242,59 +2246,87 @@ static void bestVirtualIndex(WhereBestIdx *p){ assert( pTab->azModuleArg && pTab->azModuleArg[0] ); assert( sqlite3GetVTable(pParse->db, pTab) ); - /* Set the aConstraint[].usable fields and initialize all - ** output variables to zero. - ** - ** aConstraint[].usable is true for constraints where the right-hand - ** side contains only references to tables to the left of the current - ** table. In other words, if the constraint is of the form: - ** - ** column = expr - ** - ** and we are evaluating a join, then the constraint on column is - ** only valid if all tables referenced in expr occur to the left - ** of the table containing column. - ** - ** The aConstraints[] array contains entries for all constraints - ** on the current table. That way we only have to compute it once - ** even though we might try to pick the best index multiple times. - ** For each attempt at picking an index, the order of tables in the - ** join might be different so we have to recompute the usable flag - ** each time. + /* Try once or twice. On the first attempt, allow IN optimizations. + ** If an IN optimization is accepted by the virtual table xBestIndex + ** method, but the pInfo->aConstrainUsage.omit flag is not set, then + ** the query will not work because it might allow duplicate rows in + ** output. In that case, run the xBestIndex method a second time + ** without the IN constraints. Usually this loop only runs once. + ** The loop will exit using a "break" statement. */ - pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint; - pUsage = pIdxInfo->aConstraintUsage; - for(i=0; i<pIdxInfo->nConstraint; i++, pIdxCons++){ - j = pIdxCons->iTermOffset; - pTerm = &pWC->a[j]; - pIdxCons->usable = (pTerm->prereqRight&p->notReady) ? 0 : 1; - } - memset(pUsage, 0, sizeof(pUsage[0])*pIdxInfo->nConstraint); - if( pIdxInfo->needToFreeIdxStr ){ - sqlite3_free(pIdxInfo->idxStr); - } - pIdxInfo->idxStr = 0; - pIdxInfo->idxNum = 0; - pIdxInfo->needToFreeIdxStr = 0; - pIdxInfo->orderByConsumed = 0; - /* ((double)2) In case of SQLITE_OMIT_FLOATING_POINT... */ - pIdxInfo->estimatedCost = SQLITE_BIG_DBL / ((double)2); - nOrderBy = pIdxInfo->nOrderBy; - if( !p->pOrderBy ){ - pIdxInfo->nOrderBy = 0; - } - - if( vtabBestIndex(pParse, pTab, pIdxInfo) ){ - return; - } + for(bAllowIN=1; 1; bAllowIN--){ + assert( bAllowIN==0 || bAllowIN==1 ); - pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint; - for(i=0; i<pIdxInfo->nConstraint; i++){ - if( pUsage[i].argvIndex>0 ){ - p->cost.used |= pWC->a[pIdxCons[i].iTermOffset].prereqRight; + /* Set the aConstraint[].usable fields and initialize all + ** output variables to zero. + ** + ** aConstraint[].usable is true for constraints where the right-hand + ** side contains only references to tables to the left of the current + ** table. In other words, if the constraint is of the form: + ** + ** column = expr + ** + ** and we are evaluating a join, then the constraint on column is + ** only valid if all tables referenced in expr occur to the left + ** of the table containing column. + ** + ** The aConstraints[] array contains entries for all constraints + ** on the current table. That way we only have to compute it once + ** even though we might try to pick the best index multiple times. + ** For each attempt at picking an index, the order of tables in the + ** join might be different so we have to recompute the usable flag + ** each time. + */ + pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint; + pUsage = pIdxInfo->aConstraintUsage; + for(i=0; i<pIdxInfo->nConstraint; i++, pIdxCons++){ + j = pIdxCons->iTermOffset; + pTerm = &pWC->a[j]; + if( (pTerm->prereqRight&p->notReady)==0 + && (bAllowIN || pTerm->eOperator!=WO_IN) + ){ + pIdxCons->usable = 1; + }else{ + pIdxCons->usable = 0; + } } + memset(pUsage, 0, sizeof(pUsage[0])*pIdxInfo->nConstraint); + if( pIdxInfo->needToFreeIdxStr ){ + sqlite3_free(pIdxInfo->idxStr); + } + pIdxInfo->idxStr = 0; + pIdxInfo->idxNum = 0; + pIdxInfo->needToFreeIdxStr = 0; + pIdxInfo->orderByConsumed = 0; + /* ((double)2) In case of SQLITE_OMIT_FLOATING_POINT... */ + pIdxInfo->estimatedCost = SQLITE_BIG_DBL / ((double)2); + nOrderBy = pIdxInfo->nOrderBy; + if( !p->pOrderBy ){ + pIdxInfo->nOrderBy = 0; + } + + if( vtabBestIndex(pParse, pTab, pIdxInfo) ){ + return; + } + + pIdxCons = *(struct sqlite3_index_constraint**)&pIdxInfo->aConstraint; + for(i=0; i<pIdxInfo->nConstraint; i++, pIdxCons++){ + if( pUsage[i].argvIndex>0 ){ + j = pIdxCons->iTermOffset; + pTerm = &pWC->a[j]; + p->cost.used |= pTerm->prereqRight; + if( pTerm->eOperator==WO_IN && pUsage[i].omit==0 ){ + /* Do not attempt to use an IN constraint if the virtual table + ** says that the equivalent EQ constraint cannot be safely omitted. + ** If we do attempt to use such a constraint, some rows might be + ** repeated in the output. */ + break; + } + } + } + if( i>=pIdxInfo->nConstraint ) break; } - + /* If there is an ORDER BY clause, and the selected virtual table index ** does not satisfy it, increase the cost of the scan accordingly. This ** matches the processing for non-virtual tables in bestBtreeIndex(). @@ -4063,6 +4095,7 @@ static Bitmask codeOneLoopStart( ** to access the data. */ int iReg; /* P3 Value for OP_VFilter */ + int addrNotFound; sqlite3_index_info *pVtabIdx = pLevel->plan.u.pVtabIdx; int nConstraint = pVtabIdx->nConstraint; struct sqlite3_index_constraint_usage *aUsage = @@ -4072,11 +4105,18 @@ static Bitmask codeOneLoopStart( sqlite3ExprCachePush(pParse); iReg = sqlite3GetTempRange(pParse, nConstraint+2); + addrNotFound = pLevel->addrBrk; for(j=1; j<=nConstraint; j++){ for(k=0; k<nConstraint; k++){ if( aUsage[k].argvIndex==j ){ - int iTerm = aConstraint[k].iTermOffset; - sqlite3ExprCode(pParse, pWC->a[iTerm].pExpr->pRight, iReg+j+1); + WhereTerm *pTerm = &pWC->a[aConstraint[k].iTermOffset]; + int iTarget = iReg+j+1; + if( pTerm->eOperator & WO_IN ){ + codeEqualityTerm(pParse, pTerm, pLevel, iTarget); + addrNotFound = pLevel->addrNxt; + }else{ + sqlite3ExprCode(pParse, pTerm->pExpr->pRight, iTarget); + } break; } } @@ -4084,7 +4124,7 @@ static Bitmask codeOneLoopStart( } sqlite3VdbeAddOp2(v, OP_Integer, pVtabIdx->idxNum, iReg); sqlite3VdbeAddOp2(v, OP_Integer, j-1, iReg+1); - sqlite3VdbeAddOp4(v, OP_VFilter, iCur, addrBrk, iReg, pVtabIdx->idxStr, + sqlite3VdbeAddOp4(v, OP_VFilter, iCur, addrNotFound, iReg, pVtabIdx->idxStr, pVtabIdx->needToFreeIdxStr ? P4_MPRINTF : P4_STATIC); pVtabIdx->needToFreeIdxStr = 0; for(j=0; j<nConstraint; j++){ |