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Overview
Comment: | Performance improvements for whereScan methods. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | nextgen-query-plan-exp |
Files: | files | file ages | folders |
SHA1: |
aae14350a37ad50e4607953ab496cba0 |
User & Date: | drh 2013-06-10 12:34:45.199 |
Context
2013-06-10
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14:56 | Simplification and performance tweak to the high-speed NGQP bypass. (check-in: 0f8a38ee54 user: drh tags: nextgen-query-plan-exp) | |
12:34 | Performance improvements for whereScan methods. (check-in: aae14350a3 user: drh tags: nextgen-query-plan-exp) | |
12:17 | Add a high-speed bypass for the NGQP for the common case of a simply query with quality constraints that outputs a single row. (check-in: 8d1ba30921 user: drh tags: nextgen-query-plan-exp) | |
Changes
Changes to src/where.c.
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227 228 229 230 231 232 233 | #endif /* ** An instance of the WhereScan object is used as an iterator for locating ** terms in the WHERE clause that are useful to the query planner. */ struct WhereScan { | < | 227 228 229 230 231 232 233 234 235 236 237 238 239 240 | #endif /* ** An instance of the WhereScan object is used as an iterator for locating ** terms in the WHERE clause that are useful to the query planner. */ struct WhereScan { WhereClause *pOrigWC; /* Original, innermost WhereClause */ WhereClause *pWC; /* WhereClause currently being scanned */ char *zCollName; /* Required collating sequence, if not NULL */ char idxaff; /* Must match this affinity, if zCollName!=NULL */ unsigned char nEquiv; /* Number of entries in aEquiv[] */ unsigned char iEquiv; /* Next unused slot in aEquiv[] */ u32 opMask; /* Acceptable operators */ |
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775 776 777 778 779 780 781 782 783 784 785 786 | */ WhereTerm *whereScanNext(WhereScan *pScan){ int iCur; /* The cursor on the LHS of the term */ int iColumn; /* The column on the LHS of the term. -1 for IPK */ Expr *pX; /* An expression being tested */ WhereClause *pWC; /* Shorthand for pScan->pWC */ WhereTerm *pTerm; /* The term being tested */ while( pScan->iEquiv<=pScan->nEquiv ){ iCur = pScan->aEquiv[pScan->iEquiv-2]; iColumn = pScan->aEquiv[pScan->iEquiv-1]; while( (pWC = pScan->pWC)!=0 ){ | > | | 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 | */ WhereTerm *whereScanNext(WhereScan *pScan){ int iCur; /* The cursor on the LHS of the term */ int iColumn; /* The column on the LHS of the term. -1 for IPK */ Expr *pX; /* An expression being tested */ WhereClause *pWC; /* Shorthand for pScan->pWC */ WhereTerm *pTerm; /* The term being tested */ int k = pScan->k; /* Where to start scanning */ while( pScan->iEquiv<=pScan->nEquiv ){ iCur = pScan->aEquiv[pScan->iEquiv-2]; iColumn = pScan->aEquiv[pScan->iEquiv-1]; while( (pWC = pScan->pWC)!=0 ){ for(pTerm=pWC->a+k; k<pWC->nTerm; k++, pTerm++){ if( pTerm->leftCursor==iCur && pTerm->u.leftColumn==iColumn ){ if( (pTerm->eOperator & WO_EQUIV)!=0 && pScan->nEquiv<ArraySize(pScan->aEquiv) ){ int j; pX = sqlite3ExprSkipCollate(pTerm->pExpr->pRight); assert( pX->op==TK_COLUMN ); |
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824 825 826 827 828 829 830 | if( (pTerm->eOperator & WO_EQ)!=0 && (pX = pTerm->pExpr->pRight)->op==TK_COLUMN && pX->iTable==pScan->aEquiv[0] && pX->iColumn==pScan->aEquiv[1] ){ continue; } | < | | | < | 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 | if( (pTerm->eOperator & WO_EQ)!=0 && (pX = pTerm->pExpr->pRight)->op==TK_COLUMN && pX->iTable==pScan->aEquiv[0] && pX->iColumn==pScan->aEquiv[1] ){ continue; } pScan->k = k+1; return pTerm; } } } pWC = pScan->pWC = pScan->pWC->pOuter; k = 0; } pScan->pWC = pScan->pOrigWC; k = 0; pScan->iEquiv += 2; } return 0; } /* ** Initialize a WHERE clause scanner object. Return a pointer to the ** first match. Return NULL if there are no matches. ** |
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863 864 865 866 867 868 869 | int iColumn, /* Column to scan for */ u32 opMask, /* Operator(s) to scan for */ Index *pIdx /* Must be compatible with this index */ ){ int j; /* memset(pScan, 0, sizeof(*pScan)); */ | < | 861 862 863 864 865 866 867 868 869 870 871 872 873 874 | int iColumn, /* Column to scan for */ u32 opMask, /* Operator(s) to scan for */ Index *pIdx /* Must be compatible with this index */ ){ int j; /* memset(pScan, 0, sizeof(*pScan)); */ pScan->pOrigWC = pWC; pScan->pWC = pWC; if( pIdx && iColumn>=0 ){ pScan->idxaff = pIdx->pTable->aCol[iColumn].affinity; for(j=0; pIdx->aiColumn[j]!=iColumn; j++){ if( NEVER(j>=pIdx->nColumn) ) return 0; } |
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