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Overview
| Comment: | Performance improvement to sqlite3WhereExprUsage(). |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA3-256: |
fd0934139076848f2f2edfd3d74d5460 |
| User & Date: | drh 2018-06-09 02:49:11 |
Context
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2018-06-09
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| 14:13 | Improved comments an presentation for the recent IN operator decision improvement. check-in: 31e480f6 user: drh tags: trunk | |
| 02:49 | Performance improvement to sqlite3WhereExprUsage(). check-in: fd093413 user: drh tags: trunk | |
| 01:12 | Compute the bitmask of indexed columns for each index once when the Index objecct is constructed, instead of recomputing it every time it is needed. check-in: d735872e user: drh tags: trunk | |
Changes
Changes to src/whereInt.h.
492 492 ); 493 493 494 494 /* whereexpr.c: */ 495 495 void sqlite3WhereClauseInit(WhereClause*,WhereInfo*); 496 496 void sqlite3WhereClauseClear(WhereClause*); 497 497 void sqlite3WhereSplit(WhereClause*,Expr*,u8); 498 498 Bitmask sqlite3WhereExprUsage(WhereMaskSet*, Expr*); 499 +Bitmask sqlite3WhereExprUsageNN(WhereMaskSet*, Expr*); 499 500 Bitmask sqlite3WhereExprListUsage(WhereMaskSet*, ExprList*); 500 501 void sqlite3WhereExprAnalyze(SrcList*, WhereClause*); 501 502 void sqlite3WhereTabFuncArgs(Parse*, struct SrcList_item*, WhereClause*); 502 503 503 504 504 505 505 506
Changes to src/whereexpr.c.
1012 1012 } 1013 1013 }else if( op==TK_ISNULL ){ 1014 1014 pTerm->prereqRight = 0; 1015 1015 }else{ 1016 1016 pTerm->prereqRight = sqlite3WhereExprUsage(pMaskSet, pExpr->pRight); 1017 1017 } 1018 1018 pMaskSet->bVarSelect = 0; 1019 - prereqAll = sqlite3WhereExprUsage(pMaskSet, pExpr); 1019 + prereqAll = sqlite3WhereExprUsageNN(pMaskSet, pExpr); 1020 1020 if( pMaskSet->bVarSelect ) pTerm->wtFlags |= TERM_VARSELECT; 1021 1021 if( ExprHasProperty(pExpr, EP_FromJoin) ){ 1022 1022 Bitmask x = sqlite3WhereGetMask(pMaskSet, pExpr->iRightJoinTable); 1023 1023 prereqAll |= x; 1024 1024 extraRight = x-1; /* ON clause terms may not be used with an index 1025 1025 ** on left table of a LEFT JOIN. Ticket #3015 */ 1026 1026 if( (prereqAll>>1)>=x ){ ................................................................................ 1441 1441 1442 1442 1443 1443 /* 1444 1444 ** These routines walk (recursively) an expression tree and generate 1445 1445 ** a bitmask indicating which tables are used in that expression 1446 1446 ** tree. 1447 1447 */ 1448 -Bitmask sqlite3WhereExprUsage(WhereMaskSet *pMaskSet, Expr *p){ 1448 +Bitmask sqlite3WhereExprUsageNN(WhereMaskSet *pMaskSet, Expr *p){ 1449 1449 Bitmask mask; 1450 - if( p==0 ) return 0; 1451 1450 if( p->op==TK_COLUMN ){ 1452 1451 return sqlite3WhereGetMask(pMaskSet, p->iTable); 1452 + }else if( ExprHasProperty(p, EP_TokenOnly|EP_Leaf) ){ 1453 + assert( p->op!=TK_IF_NULL_ROW ); 1454 + return 0; 1453 1455 } 1454 1456 mask = (p->op==TK_IF_NULL_ROW) ? sqlite3WhereGetMask(pMaskSet, p->iTable) : 0; 1455 - assert( !ExprHasProperty(p, EP_TokenOnly) ); 1456 - if( p->pLeft ) mask |= sqlite3WhereExprUsage(pMaskSet, p->pLeft); 1457 + if( p->pLeft ) mask |= sqlite3WhereExprUsageNN(pMaskSet, p->pLeft); 1457 1458 if( p->pRight ){ 1458 - mask |= sqlite3WhereExprUsage(pMaskSet, p->pRight); 1459 + mask |= sqlite3WhereExprUsageNN(pMaskSet, p->pRight); 1459 1460 assert( p->x.pList==0 ); 1460 1461 }else if( ExprHasProperty(p, EP_xIsSelect) ){ 1461 1462 if( ExprHasProperty(p, EP_VarSelect) ) pMaskSet->bVarSelect = 1; 1462 1463 mask |= exprSelectUsage(pMaskSet, p->x.pSelect); 1463 1464 }else if( p->x.pList ){ 1464 1465 mask |= sqlite3WhereExprListUsage(pMaskSet, p->x.pList); 1465 1466 } 1466 1467 return mask; 1468 +} 1469 +Bitmask sqlite3WhereExprUsage(WhereMaskSet *pMaskSet, Expr *p){ 1470 + return p ? sqlite3WhereExprUsageNN(pMaskSet,p) : 0; 1467 1471 } 1468 1472 Bitmask sqlite3WhereExprListUsage(WhereMaskSet *pMaskSet, ExprList *pList){ 1469 1473 int i; 1470 1474 Bitmask mask = 0; 1471 1475 if( pList ){ 1472 1476 for(i=0; i<pList->nExpr; i++){ 1473 1477 mask |= sqlite3WhereExprUsage(pMaskSet, pList->a[i].pExpr);