Many hyperlinks are disabled.
Use anonymous login
to enable hyperlinks.
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. |
|---|---|
| Downloads: | Tarball | ZIP archive | SQL archive |
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA1: | ac4e119a87497f2e422ff1cb711112ed8594bfa9 |
| User & Date: | drh 2013-01-15 18:49:07 |
Context
|
2013-01-16
| ||
| 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: d5ebb787 user: drh tags: trunk | |
|
2013-01-15
| ||
| 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: ac4e119a user: drh tags: trunk | |
| 16:15 | Clarification to a comment in where.c. No code changes. check-in: 04507c17 user: drh tags: trunk | |
Changes
Changes to src/where.c.
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
....
5157
5158
5159
5160
5161
5162
5163
5164
5165
5166
5167
5168
5169
5170
5171
|
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\n",
p->cost.plan.u.pIdx ? p->cost.plan.u.pIdx->zName : "ipk"));
bestOrClauseIndex(p);
bestAutomaticIndex(p);
p->cost.plan.wsFlags |= eqTermMask;
}
/*
................................................................................
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,
** 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));
|
|
|
>
|
|
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
....
5158
5159
5160
5161
5162
5163
5164
5165
5166
5167
5168
5169
5170
5171
5172
|
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;
}
/*
................................................................................
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));
|