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Some further performance tweaks for planning large inheritance trees that

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are mostly excluded by constraints: do the CE test a bit earlier to save
some adjust_appendrel_attrs() work on excluded children, and arrange to
use array indexing rather than rt_fetch() to fetch RTEs in the main body
of the planner.  The latter is something I'd wanted to do for awhile anyway,
but seeing list_nth_cell() as 35% of the runtime gets one's attention.
This commit is contained in:
Tom Lane
2007-04-21 21:01:45 +00:00
parent ac7e6c0665
commit afcf09dd90
11 changed files with 91 additions and 42 deletions
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47
src/backend/optimizer/path/allpaths.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/optimizer/path/allpaths.c,v 1.162 2007/04/21 06:18:52 tgl Exp $
* $PostgreSQL: pgsql/src/backend/optimizer/path/allpaths.c,v 1.163 2007/04/21 21:01:44 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -39,7 +39,8 @@ int geqo_threshold;
static void set_base_rel_pathlists(PlannerInfo *root);
static void set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, Index rti);
static void set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
Index rti, RangeTblEntry *rte);
static void set_plain_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
RangeTblEntry *rte);
static void set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
@ -144,7 +145,7 @@ set_base_rel_pathlists(PlannerInfo *root)
if (rel->reloptkind != RELOPT_BASEREL)
continue;
set_rel_pathlist(root, rel, rti);
set_rel_pathlist(root, rel, rti, root->simple_rte_array[rti]);
}
}
@ -153,10 +154,9 @@ set_base_rel_pathlists(PlannerInfo *root)
* Build access paths for a base relation
*/
static void
set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, Index rti)
set_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
Index rti, RangeTblEntry *rte)
{
RangeTblEntry *rte = rt_fetch(rti, root->parse->rtable);
if (rte->inh)
{
/* It's an "append relation", process accordingly */
@ -200,8 +200,11 @@ set_plain_rel_pathlist(PlannerInfo *root, RelOptInfo *rel, RangeTblEntry *rte)
* If we can prove we don't need to scan the rel via constraint exclusion,
* set up a single dummy path for it. (Rather than inventing a special
* "dummy" path type, we represent this as an AppendPath with no members.)
* We only need to check for regular baserels; if it's an otherrel, CE
* was already checked in set_append_rel_pathlist().
*/
if (relation_excluded_by_constraints(rel, rte))
if (rel->reloptkind == RELOPT_BASEREL &&
relation_excluded_by_constraints(rel, rte))
{
/* Set dummy size estimates --- we leave attr_widths[] as zeroes */
rel->rows = 0;
@ -294,6 +297,7 @@ set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
{
AppendRelInfo *appinfo = (AppendRelInfo *) lfirst(l);
int childRTindex;
RangeTblEntry *childRTE;
RelOptInfo *childrel;
Path *childpath;
ListCell *parentvars;
@ -304,6 +308,7 @@ set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
continue;
childRTindex = appinfo->child_relid;
childRTE = root->simple_rte_array[childRTindex];
/*
* The child rel's RelOptInfo was already created during
@ -313,18 +318,29 @@ set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
Assert(childrel->reloptkind == RELOPT_OTHER_MEMBER_REL);
/*
* Copy the parent's targetlist and quals to the child, with
* appropriate substitution of variables.
* We have to copy the parent's targetlist and quals to the child,
* with appropriate substitution of variables. However, only the
* baserestrictinfo quals are needed before we can check for
* constraint exclusion; so do that first and then check to see
* if we can disregard this child.
*/
childrel->reltargetlist = (List *)
adjust_appendrel_attrs((Node *) rel->reltargetlist,
appinfo);
childrel->baserestrictinfo = (List *)
adjust_appendrel_attrs((Node *) rel->baserestrictinfo,
appinfo);
if (relation_excluded_by_constraints(childrel, childRTE))
{
/* this child need not be scanned, so just disregard it */
continue;
}
/* CE failed, so finish copying targetlist and join quals */
childrel->joininfo = (List *)
adjust_appendrel_attrs((Node *) rel->joininfo,
appinfo);
childrel->reltargetlist = (List *)
adjust_appendrel_attrs((Node *) rel->reltargetlist,
appinfo);
/*
* We have to make child entries in the EquivalenceClass data
@ -353,12 +369,9 @@ set_append_rel_pathlist(PlannerInfo *root, RelOptInfo *rel,
* It's possible that the child is itself an appendrel, in which case
* we can "cut out the middleman" and just add its child paths to our
* own list. (We don't try to do this earlier because we need to
* apply both levels of transformation to the quals.) This test also
* handles the case where the child rel need not be scanned because of
* constraint exclusion: it'll have an Append path with no subpaths,
* and will vanish from our list.
* apply both levels of transformation to the quals.)
*/
set_rel_pathlist(root, childrel, childRTindex);
set_rel_pathlist(root, childrel, childRTindex, childRTE);
childpath = childrel->cheapest_total_path;
if (IsA(childpath, AppendPath))