diff options
Diffstat (limited to 'src/backend/optimizer/plan/planmain.c')
| -rw-r--r-- | src/backend/optimizer/plan/planmain.c | 23 |
1 files changed, 15 insertions, 8 deletions
diff --git a/src/backend/optimizer/plan/planmain.c b/src/backend/optimizer/plan/planmain.c index e82c3404b53..9e884cbb3cb 100644 --- a/src/backend/optimizer/plan/planmain.c +++ b/src/backend/optimizer/plan/planmain.c @@ -180,14 +180,19 @@ query_planner(PlannerInfo *root, List *tlist, add_base_rels_to_query(root, (Node *) parse->jointree); /* - * Examine the targetlist and qualifications, adding entries to baserel - * targetlists for all referenced Vars. Restrict and join clauses are - * added to appropriate lists belonging to the mentioned relations. We - * also build EquivalenceClasses for provably equivalent expressions, and - * form a target joinlist for make_one_rel() to work from. + * Examine the targetlist and join tree, adding entries to baserel + * targetlists for all referenced Vars, and generating PlaceHolderInfo + * entries for all referenced PlaceHolderVars. Restrict and join clauses + * are added to appropriate lists belonging to the mentioned relations. + * We also build EquivalenceClasses for provably equivalent expressions. + * The SpecialJoinInfo list is also built to hold information about join + * order restrictions. Finally, we form a target joinlist for + * make_one_rel() to work from. */ build_base_rel_tlists(root, tlist); + find_placeholders_in_jointree(root); + joinlist = deconstruct_jointree(root); /* @@ -218,10 +223,12 @@ query_planner(PlannerInfo *root, List *tlist, /* * Examine any "placeholder" expressions generated during subquery pullup. - * Make sure that we know what level to evaluate them at, and that the - * Vars they need are marked as needed. + * Make sure that the Vars they need are marked as needed at the relevant + * join level. This must be done before join removal because it might + * cause Vars or placeholders to be needed above a join when they weren't + * so marked before. */ - fix_placeholder_eval_levels(root); + fix_placeholder_input_needed_levels(root); /* * Remove any useless outer joins. Ideally this would be done during |