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Overview
Comment:Avoid unnecessary WHERE clause term tests when coding a join where one of the tables contains a OR constraint.
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SHA1: 512caa1ad30e6f699e2d006d5ab7674d55d2c746
User & Date: drh 2016-01-29 18:11:04.923
Context
2016-01-30
02:10
Make use of covering indexes in the OR optimization. (check-in: 9de3d71230 user: drh tags: trunk)
2016-01-29
19:29
Experimental attempt to make better use of covering indexes within OR queries. (check-in: a323ac3a9d user: dan tags: covering-or)
18:11
Avoid unnecessary WHERE clause term tests when coding a join where one of the tables contains a OR constraint. (check-in: 512caa1ad3 user: drh tags: trunk)
16:57
Avoid unnecessary WHERE clause term tests when coding a join where one of the tables contains a OR constraint. (Closed-Leaf check-in: ab94603974 user: drh tags: OR-clause-improvement)
08:38
Avoid two more instances of pointer arithmetic on freed pointers. (check-in: 2910ef6409 user: dan tags: trunk)
Changes
Unified Diff Ignore Whitespace Patch
Changes to src/wherecode.c.
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    */
    if( pWC->nTerm>1 ){
      int iTerm;
      for(iTerm=0; iTerm<pWC->nTerm; iTerm++){
        Expr *pExpr = pWC->a[iTerm].pExpr;
        if( &pWC->a[iTerm] == pTerm ) continue;
        if( ExprHasProperty(pExpr, EP_FromJoin) ) continue;
        if( (pWC->a[iTerm].wtFlags & TERM_VIRTUAL)!=0 ) continue;


        if( (pWC->a[iTerm].eOperator & WO_ALL)==0 ) continue;
        testcase( pWC->a[iTerm].wtFlags & TERM_ORINFO );
        pExpr = sqlite3ExprDup(db, pExpr, 0);
        pAndExpr = sqlite3ExprAnd(db, pAndExpr, pExpr);
      }
      if( pAndExpr ){
        pAndExpr = sqlite3PExpr(pParse, TK_AND|TKFLG_DONTFOLD, 0, pAndExpr, 0);








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    */
    if( pWC->nTerm>1 ){
      int iTerm;
      for(iTerm=0; iTerm<pWC->nTerm; iTerm++){
        Expr *pExpr = pWC->a[iTerm].pExpr;
        if( &pWC->a[iTerm] == pTerm ) continue;
        if( ExprHasProperty(pExpr, EP_FromJoin) ) continue;
        testcase( pWC->a[iTerm].wtFlags & TERM_VIRTUAL );
        testcase( pWC->a[iTerm].wtFlags & TERM_CODED );
        if( (pWC->a[iTerm].wtFlags & (TERM_VIRTUAL|TERM_CODED))!=0 ) continue;
        if( (pWC->a[iTerm].eOperator & WO_ALL)==0 ) continue;
        testcase( pWC->a[iTerm].wtFlags & TERM_ORINFO );
        pExpr = sqlite3ExprDup(db, pExpr, 0);
        pAndExpr = sqlite3ExprAnd(db, pAndExpr, pExpr);
      }
      if( pAndExpr ){
        pAndExpr = sqlite3PExpr(pParse, TK_AND|TKFLG_DONTFOLD, 0, pAndExpr, 0);
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