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Overview
| Comment: | Defer generating WHERE clause constraints for a RIGHT JOIN until after the ON-clause processing for the RIGHT JOIN has done its own row elimination. This fixes and incorrect output from some RIGHT JOINs that was identified by forum post 41cc3851d864c5e6. |
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| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA3-256: |
238d9c247cf69cc77fdb1af9d42ebe25 |
| User & Date: | drh 2022-05-13 17:45:52 |
Context
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2022-05-13
| ||
| 19:50 | Walk back the optimization from check-in [cc458317bd77046c] that tries to reuse the same ephemeral cursor of a list subquery when that subquery is reused, as it does not work in cases where the list subquery is used both for lookups and for scans. (check-in: 12ee29d6 user: drh tags: trunk) | |
| 17:45 | Defer generating WHERE clause constraints for a RIGHT JOIN until after the ON-clause processing for the RIGHT JOIN has done its own row elimination. This fixes and incorrect output from some RIGHT JOINs that was identified by forum post 41cc3851d864c5e6. (check-in: 238d9c24 user: drh tags: trunk) | |
| 16:38 | Redefine the acccess rules for the Expr.w union so that the Expr.w.iJoin member is accessible on either EP_OuterON or EP_InnerON. (check-in: 6f741d6c user: drh tags: trunk) | |
Changes
Changes to src/wherecode.c.
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testcase( pWInfo->untestedTerms==0
&& (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)!=0 );
pWInfo->untestedTerms = 1;
continue;
}
pE = pTerm->pExpr;
assert( pE!=0 );
| | > > | 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 |
testcase( pWInfo->untestedTerms==0
&& (pWInfo->wctrlFlags & WHERE_OR_SUBCLAUSE)!=0 );
pWInfo->untestedTerms = 1;
continue;
}
pE = pTerm->pExpr;
assert( pE!=0 );
if( (pTabItem->fg.jointype & (JT_LEFT|JT_LTORJ|JT_RIGHT))
&& (!ExprHasProperty(pE,EP_OuterON|EP_InnerON)
|| pE->w.iJoin!=pTabItem->iCursor)
){
/* Defer processing WHERE clause constraints until after outer
** join processing. tag-20220513a */
continue;
}
if( iLoop==1 && !sqlite3ExprCoveredByIndex(pE, pLevel->iTabCur, pIdx) ){
iNext = 2;
continue;
}
|
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/* For a LEFT OUTER JOIN, generate code that will record the fact that
** at least one row of the right table has matched the left table.
*/
if( pLevel->iLeftJoin ){
pLevel->addrFirst = sqlite3VdbeCurrentAddr(v);
sqlite3VdbeAddOp2(v, OP_Integer, 1, pLevel->iLeftJoin);
VdbeComment((v, "record LEFT JOIN hit"));
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/* For a LEFT OUTER JOIN, generate code that will record the fact that
** at least one row of the right table has matched the left table.
*/
if( pLevel->iLeftJoin ){
pLevel->addrFirst = sqlite3VdbeCurrentAddr(v);
sqlite3VdbeAddOp2(v, OP_Integer, 1, pLevel->iLeftJoin);
VdbeComment((v, "record LEFT JOIN hit"));
if( pLevel->pRJ==0 ){
goto code_outer_join_constraints; /* WHERE clause constraints */
}
}
if( pLevel->pRJ ){
/* Create a subroutine used to process all interior loops and code
** of the RIGHT JOIN. During normal operation, the subroutine will
** be in-line with the rest of the code. But at the end, a separate
** loop will run that invokes this subroutine for unmatched rows
** of pTab, with all tables to left begin set to NULL.
*/
WhereRightJoin *pRJ = pLevel->pRJ;
sqlite3VdbeAddOp2(v, OP_BeginSubrtn, 0, pRJ->regReturn);
pRJ->addrSubrtn = sqlite3VdbeCurrentAddr(v);
assert( pParse->withinRJSubrtn < 255 );
pParse->withinRJSubrtn++;
/* WHERE clause constraints must be deferred until after outer join
** row elimination has completed, since WHERE clause constraints apply
** to the results of the OUTER JOIN. The following loop generates the
** appropriate WHERE clause constraint checks. tag-20220513a.
*/
code_outer_join_constraints:
for(pTerm=pWC->a, j=0; j<pWC->nBase; j++, pTerm++){
testcase( pTerm->wtFlags & TERM_VIRTUAL );
testcase( pTerm->wtFlags & TERM_CODED );
if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
if( (pTerm->prereqAll & pLevel->notReady)!=0 ){
assert( pWInfo->untestedTerms );
continue;
}
if( pTabItem->fg.jointype & JT_LTORJ ) continue;
assert( pTerm->pExpr );
sqlite3ExprIfFalse(pParse, pTerm->pExpr, addrCont, SQLITE_JUMPIFNULL);
pTerm->wtFlags |= TERM_CODED;
}
}
#if WHERETRACE_ENABLED /* 0x20800 */
if( sqlite3WhereTrace & 0x20000 ){
sqlite3DebugPrintf("All WHERE-clause terms after coding level %d:\n",
iLevel);
sqlite3WhereClausePrint(pWC);
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