diff options
Diffstat (limited to 'src/backend/optimizer/plan/planner.c')
| -rw-r--r-- | src/backend/optimizer/plan/planner.c | 40 |
1 files changed, 20 insertions, 20 deletions
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c index d13035ca9ca..faca5728e6b 100644 --- a/src/backend/optimizer/plan/planner.c +++ b/src/backend/optimizer/plan/planner.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.111 2001/10/28 06:25:45 momjian Exp $ + * $Header: /cvsroot/pgsql/src/backend/optimizer/plan/planner.c,v 1.112 2001/10/30 19:58:58 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -174,6 +174,17 @@ subquery_planner(Query *parse, double tuple_fraction) EXPRKIND_HAVING); /* + * Check for ungrouped variables passed to subplans in targetlist and + * HAVING clause (but not in WHERE or JOIN/ON clauses, since those are + * evaluated before grouping). We can't do this any earlier because + * we must use the preprocessed targetlist for comparisons of grouped + * expressions. + */ + if (parse->hasSubLinks && + (parse->groupClause != NIL || parse->hasAggs)) + check_subplans_for_ungrouped_vars(parse); + + /* * A HAVING clause without aggregates is equivalent to a WHERE clause * (except it can only refer to grouped fields). Transfer any * agg-free clauses of the HAVING qual into WHERE. This may seem like @@ -623,23 +634,10 @@ preprocess_expression(Query *parse, Node *expr, int kind) #endif } + /* Expand SubLinks to SubPlans */ if (parse->hasSubLinks) - { - /* Expand SubLinks to SubPlans */ expr = SS_process_sublinks(expr); - if (kind != EXPRKIND_WHERE && - (parse->groupClause != NIL || parse->hasAggs)) - { - /* - * Check for ungrouped variables passed to subplans. Note we - * do NOT do this for subplans in WHERE (or JOIN/ON); it's - * legal there because WHERE is evaluated pre-GROUP. - */ - check_subplans_for_ungrouped_vars(expr, parse); - } - } - /* Replace uplevel vars with Param nodes */ if (PlannerQueryLevel > 1) expr = SS_replace_correlation_vars(expr); @@ -1122,12 +1120,11 @@ grouping_planner(Query *parse, double tuple_fraction) /* * If there are aggregates then the Group node should just return - * the same set of vars as the subplan did (but we can exclude any - * GROUP BY expressions). If there are no aggregates then the - * Group node had better compute the final tlist. + * the same set of vars as the subplan did. If there are no aggs + * then the Group node had better compute the final tlist. */ if (parse->hasAggs) - group_tlist = flatten_tlist(result_plan->targetlist); + group_tlist = new_unsorted_tlist(result_plan->targetlist); else group_tlist = tlist; @@ -1234,7 +1231,10 @@ grouping_planner(Query *parse, double tuple_fraction) * where the a+b target will be used by the Sort/Group steps, and the * other targets will be used for computing the final results. (In the * above example we could theoretically suppress the a and b targets and - * use only a+b, but it's not really worth the trouble.) + * pass down only c,d,a+b, but it's not really worth the trouble to + * eliminate simple var references from the subplan. We will avoid doing + * the extra computation to recompute a+b at the outer level; see + * replace_vars_with_subplan_refs() in setrefs.c.) * * 'parse' is the query being processed. * 'tlist' is the query's target list. |