From b0cc0a71e0a0a760f54c72edb8cd000e4555442b Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Wed, 17 Sep 2025 16:32:57 -0400 Subject: Calculate agglevelsup correctly when Aggref contains a CTE. If an aggregate function call contains a sub-select that has an RTE referencing a CTE outside the aggregate, we must treat that reference like a Var referencing the CTE's query level for purposes of determining the aggregate's level. Otherwise we might reach the nonsensical conclusion that the aggregate should be evaluated at some query level higher than the CTE, ending in a planner error or a broken plan tree that causes executor failures. Bug: #19055 Reported-by: BugForge Author: Tom Lane Discussion: https://postgr.es/m/19055-6970cfa8556a394d@postgresql.org Backpatch-through: 13 --- src/backend/parser/parse_agg.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) (limited to 'src/backend/parser/parse_agg.c') diff --git a/src/backend/parser/parse_agg.c b/src/backend/parser/parse_agg.c index 0ac8966e30f..3254c83cc6c 100644 --- a/src/backend/parser/parse_agg.c +++ b/src/backend/parser/parse_agg.c @@ -791,6 +791,32 @@ check_agg_arguments_walker(Node *node, parser_errposition(context->pstate, ((WindowFunc *) node)->location))); } + + if (IsA(node, RangeTblEntry)) + { + /* + * CTE references act similarly to Vars of the CTE's level. Without + * this we might conclude that the Agg can be evaluated above the CTE, + * leading to trouble. + */ + RangeTblEntry *rte = (RangeTblEntry *) node; + + if (rte->rtekind == RTE_CTE) + { + int ctelevelsup = rte->ctelevelsup; + + /* convert levelsup to frame of reference of original query */ + ctelevelsup -= context->sublevels_up; + /* ignore local CTEs of subqueries */ + if (ctelevelsup >= 0) + { + if (context->min_varlevel < 0 || + context->min_varlevel > ctelevelsup) + context->min_varlevel = ctelevelsup; + } + } + return false; /* allow range_table_walker to continue */ + } if (IsA(node, Query)) { /* Recurse into subselects */ @@ -800,7 +826,7 @@ check_agg_arguments_walker(Node *node, result = query_tree_walker((Query *) node, check_agg_arguments_walker, context, - 0); + QTW_EXAMINE_RTES_BEFORE); context->sublevels_up--; return result; } -- cgit v1.2.3