From 4ebad7d772827fe2f3f34fcf6681d49fe4a829ff Mon Sep 17 00:00:00 2001 From: Sergey Soloviev Date: Fri, 22 Aug 2025 16:37:02 +0300 Subject: [PATCH] fix: variable not found in subplan target lists When restoring 'attr_needed' after self-join removal we should also consider EC with constants because some plan nodes can use such constant attributes. For example, after converting `EXISTS` to JOIN planner can create `UniquePath` referencing attribute which is contained in EC with constant. But because `attr_needed` is NULL then this attribute is not returned by JOIN, so at `set_plan_references` fails to find this attribute in targetlist of node below. --- src/backend/optimizer/path/equivclass.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff --git a/src/backend/optimizer/path/equivclass.c b/src/backend/optimizer/path/equivclass.c index 441f12f6c50..58ca75ab7a8 100644 --- a/src/backend/optimizer/path/equivclass.c +++ b/src/backend/optimizer/path/equivclass.c @@ -2586,18 +2586,27 @@ rebuild_eclass_attr_needed(PlannerInfo *root) */ Assert(ec->ec_childmembers == NULL); - /* Need do anything only for a multi-member, no-const EC. */ - if (list_length(ec->ec_members) > 1 && !ec->ec_has_const) + /* + * Need do anything only for a multi-member. Note that some + * wrapping plan nodes (i.e. UniquePath) can reference attributes + * contained in EC with constants. + */ + if (list_length(ec->ec_members) > 1) { ListCell *lc2; foreach(lc2, ec->ec_members) { EquivalenceMember *cur_em = (EquivalenceMember *) lfirst(lc2); - List *vars = pull_var_clause((Node *) cur_em->em_expr, - PVC_RECURSE_AGGREGATES | - PVC_RECURSE_WINDOWFUNCS | - PVC_INCLUDE_PLACEHOLDERS); + List *vars; + + if (cur_em->em_is_const) + continue; + + vars = pull_var_clause((Node *) cur_em->em_expr, + PVC_RECURSE_AGGREGATES | + PVC_RECURSE_WINDOWFUNCS | + PVC_INCLUDE_PLACEHOLDERS); add_vars_to_attr_needed(root, vars, ec->ec_relids); list_free(vars); -- 2.43.0