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Overview
| Comment: | Performance tweak to whereLoopInsert(). |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | nextgen-query-plan-exp |
| Files: | files | file ages | folders |
| SHA1: |
1c4a78807b7a28c9976ca8c5722ff4e2 |
| User & Date: | drh 2013-06-05 12:47:59 |
Context
|
2013-06-05
| ||
| 16:19 | Minor performance tuning of the NGQP. check-in: cbef38c2 user: drh tags: nextgen-query-plan-exp | |
| 12:47 | Performance tweak to whereLoopInsert(). check-in: 1c4a7880 user: drh tags: nextgen-query-plan-exp | |
| 12:18 | Add a test case contributed on the mailing list that works in NGQP but fails in legacy. check-in: 96afe508 user: drh tags: nextgen-query-plan-exp | |
Changes
Changes to src/where.c.
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}
/* Search for an existing WhereLoop to overwrite, or which takes
** priority over pTemplate.
*/
for(ppPrev=&pWInfo->pLoops, p=*ppPrev; p; ppPrev=&p->pNextLoop, p=*ppPrev){
if( p->iTab!=pTemplate->iTab || p->iSortIdx!=pTemplate->iSortIdx ) continue;
if( p->nTerm<pTemplate->nTerm
&& (p->wsFlags & WHERE_INDEXED)!=0
&& (pTemplate->wsFlags & WHERE_INDEXED)!=0
&& p->u.btree.pIndex==pTemplate->u.btree.pIndex
&& p->prereq==pTemplate->prereq
){
/* Overwrite an existing WhereLoop with an similar one that uses
** more terms of the index */
pNext = p->pNextLoop;
whereLoopClear(db, p);
break;
}
if( (p->prereq & pTemplate->prereq)==p->prereq
&& p->rSetup<=pTemplate->rSetup
&& p->rRun<=pTemplate->rRun
){
/* Already holding an equal or better WhereLoop.
** Return without changing or adding anything */
goto whereLoopInsert_noop;
}
if( (p->prereq & pTemplate->prereq)==pTemplate->prereq
&& p->rSetup>=pTemplate->rSetup
&& p->rRun>=pTemplate->rRun
){
/* Overwrite an existing WhereLoop with a better one */
pNext = p->pNextLoop;
|
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3855 3856 3857 3858 3859 3860 3861 3862 3863 3864 3865 3866 3867 3868 3869 3870 3871 3872 3873 3874 3875 3876 3877 3878 3879 3880 3881 3882 3883 3884 3885 3886 3887 3888 3889 |
}
/* Search for an existing WhereLoop to overwrite, or which takes
** priority over pTemplate.
*/
for(ppPrev=&pWInfo->pLoops, p=*ppPrev; p; ppPrev=&p->pNextLoop, p=*ppPrev){
if( p->iTab!=pTemplate->iTab || p->iSortIdx!=pTemplate->iSortIdx ) continue;
if( (p->prereq & pTemplate->prereq)==p->prereq
&& p->rSetup<=pTemplate->rSetup
&& p->rRun<=pTemplate->rRun
){
/* p is equal or better than pTemplate */
if( p->nTerm<pTemplate->nTerm
&& (p->wsFlags & WHERE_INDEXED)!=0
&& (pTemplate->wsFlags & WHERE_INDEXED)!=0
&& p->u.btree.pIndex==pTemplate->u.btree.pIndex
&& p->prereq==pTemplate->prereq
){
/* Overwrite an existing WhereLoop with an similar one that uses
** more terms of the index */
pNext = p->pNextLoop;
whereLoopClear(db, p);
break;
}else{
/* pTemplate is not helpful.
** Return without changing or adding anything */
goto whereLoopInsert_noop;
}
}
if( (p->prereq & pTemplate->prereq)==pTemplate->prereq
&& p->rSetup>=pTemplate->rSetup
&& p->rRun>=pTemplate->rRun
){
/* Overwrite an existing WhereLoop with a better one */
pNext = p->pNextLoop;
|