diff options
Diffstat (limited to 'src/backend/optimizer/plan/planner.c')
| -rw-r--r-- | src/backend/optimizer/plan/planner.c | 46 |
1 files changed, 31 insertions, 15 deletions
diff --git a/src/backend/optimizer/plan/planner.c b/src/backend/optimizer/plan/planner.c index d8f228f2b94..1831c1bb9ca 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 1.175 2004/08/30 02:54:38 momjian Exp $ + * $PostgreSQL: pgsql/src/backend/optimizer/plan/planner.c,v 1.176 2004/10/02 22:39:46 tgl Exp $ * *------------------------------------------------------------------------- */ @@ -320,8 +320,7 @@ subquery_planner(Query *parse, double tuple_fraction) * grouping_planner. */ if (parse->resultRelation && - (lst = expand_inherited_rtentry(parse, parse->resultRelation, - false)) != NIL) + (lst = expand_inherited_rtentry(parse, parse->resultRelation)) != NIL) plan = inheritance_planner(parse, lst); else plan = grouping_planner(parse, tuple_fraction); @@ -513,7 +512,6 @@ inheritance_planner(Query *parse, List *inheritlist) { int childRTindex = lfirst_int(l); Oid childOID = getrelid(childRTindex, parse->rtable); - int subrtlength; Query *subquery; Plan *subplan; @@ -526,22 +524,40 @@ inheritance_planner(Query *parse, List *inheritlist) subplans = lappend(subplans, subplan); /* - * It's possible that additional RTEs got added to the rangetable - * due to expansion of inherited source tables (see allpaths.c). - * If so, we must copy 'em back to the main parse tree's rtable. + * XXX my goodness this next bit is ugly. Really need to think about + * ways to rein in planner's habit of scribbling on its input. * - * XXX my goodness this is ugly. Really need to think about ways to - * rein in planner's habit of scribbling on its input. + * Planning of the subquery might have modified the rangetable, + * either by addition of RTEs due to expansion of inherited source + * tables, or by changes of the Query structures inside subquery + * RTEs. We have to ensure that this gets propagated back to the + * master copy. However, if we aren't done planning yet, we also + * need to ensure that subsequent calls to grouping_planner have + * virgin sub-Queries to work from. So, if we are at the last + * list entry, just copy the subquery rangetable back to the master + * copy; if we are not, then extend the master copy by adding + * whatever the subquery added. (We assume these added entries + * will go untouched by the future grouping_planner calls. We are + * also effectively assuming that sub-Queries will get planned + * identically each time, or at least that the impacts on their + * rangetables will be the same each time. Did I say this is ugly?) */ - subrtlength = list_length(subquery->rtable); - if (subrtlength > mainrtlength) + if (lnext(l) == NULL) + parse->rtable = subquery->rtable; + else { - List *subrt; + int subrtlength = list_length(subquery->rtable); + + if (subrtlength > mainrtlength) + { + List *subrt; - subrt = list_copy_tail(subquery->rtable, mainrtlength); - parse->rtable = list_concat(parse->rtable, subrt); - mainrtlength = subrtlength; + subrt = list_copy_tail(subquery->rtable, mainrtlength); + parse->rtable = list_concat(parse->rtable, subrt); + mainrtlength = subrtlength; + } } + /* Save preprocessed tlist from first rel for use in Append */ if (tlist == NIL) tlist = subplan->targetlist; |