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Overview
Comment: | Fix a missing word in a comment. Enhance the "wheretrace" debugging output to show the estimated cost of each table option while planning the join order. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
ac4e119a87497f2e422ff1cb711112ed |
User & Date: | drh 2013-01-15 18:49:07.627 |
Context
2013-01-16
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00:46 | Improvements to query planning for joins: Avoid unnecessary calls to "optimal scan" checks in cases where table reordering is not possible. Make sure optimal scan checks are carried out for CROSS JOINs and LEFT JOINs. (check-in: d5ebb78778 user: drh tags: trunk) | |
2013-01-15
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18:49 | Fix a missing word in a comment. Enhance the "wheretrace" debugging output to show the estimated cost of each table option while planning the join order. (check-in: ac4e119a87 user: drh tags: trunk) | |
16:15 | Clarification to a comment in where.c. No code changes. (check-in: 04507c1763 user: drh tags: trunk) | |
Changes
Changes to src/where.c.
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3565 3566 3567 3568 3569 3570 3571 | assert( p->pOrderBy || (p->cost.plan.wsFlags&WHERE_ORDERED)==0 ); assert( p->cost.plan.u.pIdx==0 || (p->cost.plan.wsFlags&WHERE_ROWID_EQ)==0 ); assert( pSrc->pIndex==0 || p->cost.plan.u.pIdx==0 || p->cost.plan.u.pIdx==pSrc->pIndex ); | | | > | 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581 | assert( p->pOrderBy || (p->cost.plan.wsFlags&WHERE_ORDERED)==0 ); assert( p->cost.plan.u.pIdx==0 || (p->cost.plan.wsFlags&WHERE_ROWID_EQ)==0 ); assert( pSrc->pIndex==0 || p->cost.plan.u.pIdx==0 || p->cost.plan.u.pIdx==pSrc->pIndex ); WHERETRACE((" best index is %s cost=%.1f\n", p->cost.plan.u.pIdx ? p->cost.plan.u.pIdx->zName : "ipk", p->cost.rCost)); bestOrClauseIndex(p); bestAutomaticIndex(p); p->cost.plan.wsFlags |= eqTermMask; } /* |
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5157 5158 5159 5160 5161 5162 5163 | if( isOptimal && (sWBI.cost.plan.wsFlags & WHERE_NOT_FULLSCAN)==0 ){ notIndexed |= m; } if( isOptimal ){ pWInfo->a[j].rOptCost = sWBI.cost.rCost; }else if( iFrom<nTabList-1 ){ | | | 5158 5159 5160 5161 5162 5163 5164 5165 5166 5167 5168 5169 5170 5171 5172 | if( isOptimal && (sWBI.cost.plan.wsFlags & WHERE_NOT_FULLSCAN)==0 ){ notIndexed |= m; } if( isOptimal ){ pWInfo->a[j].rOptCost = sWBI.cost.rCost; }else if( iFrom<nTabList-1 ){ /* If two or more tables have nearly the same outer loop cost, but ** very different inner loop (optimal) cost, we want to choose ** for the outer loop that table which benefits the least from ** being in the inner loop. The following code scales the ** outer loop cost estimate to accomplish that. */ WHERETRACE((" scaling cost from %.1f to %.1f\n", sWBI.cost.rCost, sWBI.cost.rCost/pWInfo->a[j].rOptCost)); |
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