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Use of the CROSS keyword in a join prevents table reordering. Ticket #1414. (CVS 2683)

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FossilOrigin-Name: 415b8b24629aa12756d8285c094b5f85d8a8e532
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drh
2005-09-10 15:28:09 +00:00
parent f307a4aaf8
commit 3dec223ca0
5 changed files with 26 additions and 20 deletions
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10
src/where.c
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@@ -16,7 +16,7 @@
** so is applicable. Because this module is responsible for selecting
** indices, you might also think of this module as the "query optimizer".
**
** $Id: where.c,v 1.169 2005/09/08 14:17:20 drh Exp $
** $Id: where.c,v 1.170 2005/09/10 15:28:09 drh Exp $
*/
#include "sqliteInt.h"
@@ -1425,6 +1425,7 @@ WhereInfo *sqlite3WhereBegin(
pTabItem = pTabList->a;
pLevel = pWInfo->a;
andFlags = ~0;
TRACE(("*** Optimizer Start ***\n"));
for(i=iFrom=0, pLevel=pWInfo->a; i<pTabList->nSrc; i++, pLevel++){
Index *pIdx; /* Index for FROM table at pTabItem */
int flags; /* Flags asssociated with pIdx */
@@ -1454,12 +1455,14 @@ WhereInfo *sqlite3WhereBegin(
bestNEq = nEq;
bestJ = j;
}
if( (pTabItem->jointype & JT_LEFT)!=0
|| (j>0 && (pTabItem[-1].jointype & JT_LEFT)!=0)
if( (pTabItem->jointype & (JT_LEFT|JT_CROSS))!=0
|| (j>0 && (pTabItem[-1].jointype & (JT_LEFT|JT_CROSS))!=0)
){
break;
}
}
TRACE(("*** Optimizer choose table %d for loop %d\n", bestJ,
pLevel-pWInfo->a));
if( (bestFlags & WHERE_ORDERBY)!=0 ){
*ppOrderBy = 0;
}
@@ -1477,6 +1480,7 @@ WhereInfo *sqlite3WhereBegin(
notReady &= ~getMask(&maskSet, pTabList->a[bestJ].iCursor);
pLevel->iFrom = bestJ;
}
TRACE(("*** Optimizer Finished ***\n"));
/* If the total query only selects a single row, then the ORDER BY
** clause is irrelevant.