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Simplify the planner's join clause management by storing join clauses

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of a relation in a flat 'joininfo' list.  The former arrangement grouped
the join clauses according to the set of unjoined relids used in each;
however, profiling on test cases involving lots of joins proves that
that data structure is a net loss.  It takes more time to group the
join clauses together than is saved by avoiding duplicate tests later.
It doesn't help any that there are usually not more than one or two
clauses per group ...
This commit is contained in:
Tom Lane
2005-06-09 04:19:00 +00:00
parent c51815afed
commit a31ad27fc5
19 changed files with 285 additions and 465 deletions
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58
src/backend/optimizer/path/orindxpath.c
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@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/optimizer/path/orindxpath.c,v 1.71 2005/06/05 22:32:55 tgl Exp $
* $PostgreSQL: pgsql/src/backend/optimizer/path/orindxpath.c,v 1.72 2005/06/09 04:18:59 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -96,43 +96,37 @@ create_or_index_quals(PlannerInfo *root, RelOptInfo *rel)
*/
foreach(i, rel->joininfo)
{
JoinInfo *joininfo = (JoinInfo *) lfirst(i);
ListCell *j;
RestrictInfo *rinfo = (RestrictInfo *) lfirst(i);
foreach(j, joininfo->jinfo_restrictinfo)
if (restriction_is_or_clause(rinfo) &&
rinfo->valid_everywhere)
{
RestrictInfo *rinfo = (RestrictInfo *) lfirst(j);
/*
* Use the generate_bitmap_or_paths() machinery to estimate
* the value of each OR clause. We can use regular
* restriction clauses along with the OR clause contents to
* generate indexquals. We pass outer_relids = NULL so that
* sub-clauses that are actually joins will be ignored.
*/
List *orpaths;
ListCell *k;
if (restriction_is_or_clause(rinfo) &&
rinfo->valid_everywhere)
orpaths = generate_bitmap_or_paths(root, rel,
list_make1(rinfo),
rel->baserestrictinfo,
false, NULL);
/* Locate the cheapest OR path */
foreach(k, orpaths)
{
/*
* Use the generate_bitmap_or_paths() machinery to estimate
* the value of each OR clause. We can use regular
* restriction clauses along with the OR clause contents to
* generate indexquals. We pass outer_relids = NULL so that
* sub-clauses that are actually joins will be ignored.
*/
List *orpaths;
ListCell *k;
BitmapOrPath *path = (BitmapOrPath *) lfirst(k);
orpaths = generate_bitmap_or_paths(root, rel,
list_make1(rinfo),
rel->baserestrictinfo,
false, NULL);
/* Locate the cheapest OR path */
foreach(k, orpaths)
Assert(IsA(path, BitmapOrPath));
if (bestpath == NULL ||
path->path.total_cost < bestpath->path.total_cost)
{
BitmapOrPath *path = (BitmapOrPath *) lfirst(k);
Assert(IsA(path, BitmapOrPath));
if (bestpath == NULL ||
path->path.total_cost < bestpath->path.total_cost)
{
bestpath = path;
bestrinfo = rinfo;
}
bestpath = path;
bestrinfo = rinfo;
}
}
}