From 8db2f4144b03e4ac093c3f46924f95b40e283e33 Mon Sep 17 00:00:00 2001
From: Mehmet Yilmaz <mehmetyilmaz@microsoft.com>
Date: Tue, 17 Jun 2025 12:06:04 +0000
Subject: [PATCH] Introduce an RTE for the grouping step

247dea89f7616fdf06b7272b74abafc29e8e5860
---
 .../distributed/deparser/ruleutils_18.c       | 19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

diff --git a/src/backend/distributed/deparser/ruleutils_18.c b/src/backend/distributed/deparser/ruleutils_18.c
index 2d01b4732..deecebb27 100644
--- a/src/backend/distributed/deparser/ruleutils_18.c
+++ b/src/backend/distributed/deparser/ruleutils_18.c
@@ -2218,11 +2218,28 @@ get_query_def_extended(Query *query, StringInfo buf, List *parentnamespace,
 {
 	deparse_context context;
 	deparse_namespace dpns;
+	int			rtable_size;
 
 	/* Guard against excessively long or deeply-nested queries */
 	CHECK_FOR_INTERRUPTS();
 	check_stack_depth();
 
+	rtable_size = query->hasGroupRTE ?
+		list_length(query->rtable) - 1 :
+		list_length(query->rtable);
+
+	/*
+	 * Replace any Vars in the query's targetlist and havingQual that
+	 * reference GROUP outputs with the underlying grouping expressions.
+	 */
+	if (query->hasGroupRTE)
+	{
+		query->targetList = (List *)
+			flatten_group_exprs(NULL, query, (Node *) query->targetList);
+		query->havingQual =
+			flatten_group_exprs(NULL, query, query->havingQual);
+	}
+
 	/*
 	 * Before we begin to examine the query, acquire locks on referenced
 	 * relations, and fix up deleted columns in JOIN RTEs.  This ensures
@@ -2247,7 +2264,7 @@ get_query_def_extended(Query *query, StringInfo buf, List *parentnamespace,
 	context.targetList = NIL;
 	context.windowClause = NIL;
 	context.varprefix = (parentnamespace != NIL ||
-						 list_length(query->rtable) != 1);
+						 rtable_size != 1);
 	context.prettyFlags = prettyFlags;
 	context.wrapColumn = wrapColumn;
 	context.indentLevel = startIndent;