diff options
Diffstat (limited to 'src/backend/optimizer/plan/planner.c')
| -rw-r--r-- | src/backend/optimizer/plan/planner.c | 17 |
1 files changed, 10 insertions, 7 deletions
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c index df8d0556b42..334f8504dff 100644 --- a/src/backend/optimizer/plan/planner.c +++ b/src/backend/optimizer/plan/planner.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $PostgreSQL: pgsql/src/backend/optimizer/plan/planner.c,v 1.189 2005/06/10 02:21:04 tgl Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/plan/planner.c,v 1.190 2005/07/02 23:00:41 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -194,7 +194,6 @@ subquery_planner(Query *parse, double tuple_fraction, int saved_planid = PlannerPlanId; PlannerInfo *root; Plan *plan; - bool hasOuterJoins; List *newHaving; List *lst; ListCell *l; @@ -228,12 +227,16 @@ subquery_planner(Query *parse, double tuple_fraction, /* * Detect whether any rangetable entries are RTE_JOIN kind; if not, we * can avoid the expense of doing flatten_join_alias_vars(). Also - * check for outer joins --- if none, we can skip - * reduce_outer_joins(). This must be done after we have done + * check for outer joins --- if none, we can skip reduce_outer_joins() + * and some other processing. This must be done after we have done * pull_up_subqueries, of course. + * + * Note: if reduce_outer_joins manages to eliminate all outer joins, + * root->hasOuterJoins is not reset currently. This is OK since its + * purpose is merely to suppress unnecessary processing in simple cases. */ root->hasJoinRTEs = false; - hasOuterJoins = false; + root->hasOuterJoins = false; foreach(l, parse->rtable) { RangeTblEntry *rte = (RangeTblEntry *) lfirst(l); @@ -243,7 +246,7 @@ subquery_planner(Query *parse, double tuple_fraction, root->hasJoinRTEs = true; if (IS_OUTER_JOIN(rte->jointype)) { - hasOuterJoins = true; + root->hasOuterJoins = true; /* Can quit scanning once we find an outer join */ break; } @@ -347,7 +350,7 @@ subquery_planner(Query *parse, double tuple_fraction, * joins. This step is most easily done after we've done expression * preprocessing. */ - if (hasOuterJoins) + if (root->hasOuterJoins) reduce_outer_joins(root); /* |