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Repair planner failure for cases involving Cartesian products inside

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IN (sub-SELECT) constructs.  We must force a clauseless join of the
sub-select member relations, but it wasn't happening because the code
thought it would be able to use the join clause arising from the IN.
This commit is contained in:
Tom Lane 2004-01-24 00:37:28 +00:00
parent 3969f2924b
commit 5d66583678
1 changed files with 41 additions and 5 deletions
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46
src/backend/optimizer/path/joinrels.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/optimizer/path/joinrels.c,v 1.65 2003/12/17 17:07:48 tgl Exp $
* $PostgreSQL: pgsql/src/backend/optimizer/path/joinrels.c,v 1.66 2004/01/24 00:37:28 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -24,6 +24,7 @@ static List *make_rels_by_clause_joins(Query *root,
static List *make_rels_by_clauseless_joins(Query *root,
RelOptInfo *old_rel,
List *other_rels);
static bool is_inside_IN(Query *root, RelOptInfo *rel);
/*
@ -76,14 +77,26 @@ make_rels_by_joins(Query *root, int level, List **joinrels)
/*
* Note that if all available join clauses for this rel
* require more than one other rel, we will fail to make any
* joins against it here. That's OK; it'll be considered by
* "bushy plan" join code in a higher-level pass where we have
* those other rels collected into a join rel. See also the
* last-ditch case below.
* joins against it here. In most cases that's OK; it'll be
* considered by "bushy plan" join code in a higher-level pass
* where we have those other rels collected into a join rel.
*/
new_rels = make_rels_by_clause_joins(root,
old_rel,
other_rels);
/*
* An exception occurs when there is a clauseless join inside an
* IN (sub-SELECT) construct. Here, the members of the subselect
* all have join clauses (against the stuff outside the IN), but
* they *must* be joined to each other before we can make use of
* those join clauses. So do the clauseless join bit.
*
* See also the last-ditch case below.
*/
if (new_rels == NIL && is_inside_IN(root, old_rel))
new_rels = make_rels_by_clauseless_joins(root,
old_rel,
other_rels);
}
else
{
@ -347,6 +360,29 @@ make_rels_by_clauseless_joins(Query *root,
}
/*
* is_inside_IN
* Detect whether the specified relation is inside an IN (sub-SELECT).
*
* Note that we are actually only interested in rels that have been pulled up
* out of an IN, so the routine name is a slight misnomer.
*/
static bool
is_inside_IN(Query *root, RelOptInfo *rel)
{
List *i;
foreach(i, root->in_info_list)
{
InClauseInfo *ininfo = (InClauseInfo *) lfirst(i);
if (bms_is_subset(rel->relids, ininfo->righthand))
return true;
}
return false;
}
/*
* make_jointree_rel
* Find or build a RelOptInfo join rel representing a specific