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Overview
Comment: | Avoid redundant constraint checking due to transitive constraints. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
329478cbed06f93652de50abdb31a6b4 |
User & Date: | drh 2013-05-01 17:22:38.014 |
Context
2013-05-01
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17:58 | Do not use a transitive constraint to an IN operator where the RHS is a constant if there exists a direct == operator to another table in an outer loop. (check-in: faedaeace9 user: drh tags: trunk) | |
17:22 | Avoid redundant constraint checking due to transitive constraints. (check-in: 329478cbed user: drh tags: trunk) | |
2013-04-30
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14:25 | Update the documentation to explain that when the 3rd parameter to sqlite3_bind_text() and friends is NULL the result is to bind a NULL SQL value. Ticket [19b44e35753ba] (check-in: bd92de0e8d user: drh tags: trunk) | |
Changes
Changes to src/where.c.
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4879 4880 4881 4882 4883 4884 4885 4886 4887 4888 4889 4890 4891 4892 | if( pTerm->eOperator!=(WO_EQUIV|WO_EQ) ) continue; if( pTerm->leftCursor!=iCur ) continue; pE = pTerm->pExpr; assert( !ExprHasProperty(pE, EP_FromJoin) ); assert( (pTerm->prereqRight & newNotReady)!=0 ); pAlt = findTerm(pWC, iCur, pTerm->u.leftColumn, notReady, WO_EQ|WO_IN, 0); if( pAlt==0 ) continue; VdbeNoopComment((v, "begin transitive constraint")); sEq = *pAlt->pExpr; sEq.pLeft = pE->pLeft; sqlite3ExprIfFalse(pParse, &sEq, addrCont, SQLITE_JUMPIFNULL); } /* For a LEFT OUTER JOIN, generate code that will record the fact that | > | 4879 4880 4881 4882 4883 4884 4885 4886 4887 4888 4889 4890 4891 4892 4893 | if( pTerm->eOperator!=(WO_EQUIV|WO_EQ) ) continue; if( pTerm->leftCursor!=iCur ) continue; pE = pTerm->pExpr; assert( !ExprHasProperty(pE, EP_FromJoin) ); assert( (pTerm->prereqRight & newNotReady)!=0 ); pAlt = findTerm(pWC, iCur, pTerm->u.leftColumn, notReady, WO_EQ|WO_IN, 0); if( pAlt==0 ) continue; if( pAlt->wtFlags & (TERM_CODED) ) continue; VdbeNoopComment((v, "begin transitive constraint")); sEq = *pAlt->pExpr; sEq.pLeft = pE->pLeft; sqlite3ExprIfFalse(pParse, &sEq, addrCont, SQLITE_JUMPIFNULL); } /* For a LEFT OUTER JOIN, generate code that will record the fact that |
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