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Dept. of second thoughts: clause_selectivity shouldn't try to cache its

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result for jointypes associated with IN processing.
This commit is contained in:
Tom Lane
2004-01-05 16:44:40 +00:00
parent 9091e8d1b2
commit cce442da6d
1 changed files with 29 additions and 8 deletions
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29
src/backend/optimizer/path/clausesel.c
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@@ -8,7 +8,7 @@
* *
* *
* IDENTIFICATION * IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/optimizer/path/clausesel.c,v 1.63 2004/01/04 03:51:52 tgl Exp $ * $PostgreSQL: pgsql/src/backend/optimizer/path/clausesel.c,v 1.64 2004/01/05 16:44:40 tgl Exp $
* *
*------------------------------------------------------------------------- *-------------------------------------------------------------------------
*/ */
@@ -417,17 +417,38 @@ clause_selectivity(Query *root,
* If possible, cache the result of the selectivity calculation for * If possible, cache the result of the selectivity calculation for
* the clause. We can cache if varRelid is zero or the clause * the clause. We can cache if varRelid is zero or the clause
* contains only vars of that relid --- otherwise varRelid will affect * contains only vars of that relid --- otherwise varRelid will affect
* the result, so mustn't cache. We ignore the possibility that * the result, so mustn't cache. We also have to be careful about
* jointype will affect the result, which should be okay because outer * the jointype. It's OK to cache when jointype is JOIN_INNER or
* join clauses will always be examined with the same jointype value. * one of the outer join types (any given outer-join clause should
* always be examined with the same jointype, so result won't change).
* It's not OK to cache when jointype is one of the special types
* associated with IN processing, because the same clause may be
* examined with different jointypes and the result should vary.
*/ */
if (varRelid == 0 || if (varRelid == 0 ||
bms_is_subset_singleton(rinfo->clause_relids, varRelid)) bms_is_subset_singleton(rinfo->clause_relids, varRelid))
{ {
switch (jointype)
{
case JOIN_INNER:
case JOIN_LEFT:
case JOIN_FULL:
case JOIN_RIGHT:
/* Cacheable --- do we already have the result? */ /* Cacheable --- do we already have the result? */
if (rinfo->this_selec >= 0) if (rinfo->this_selec >= 0)
return rinfo->this_selec; return rinfo->this_selec;
cacheable = true; cacheable = true;
break;
case JOIN_UNION:
/* unimplemented anyway... */
case JOIN_IN:
case JOIN_REVERSE_IN:
case JOIN_UNIQUE_OUTER:
case JOIN_UNIQUE_INNER:
/* unsafe to cache */
break;
}
} }
/* Proceed with examination of contained clause */ /* Proceed with examination of contained clause */