From 3144099254e3e5654c3c1e741b94290ef6baa1b0 Mon Sep 17 00:00:00 2001
From: Sven Klemm <sven@timescale.com>
Date: Sat, 7 Oct 2023 21:38:57 +0200
Subject: [PATCH] Fix first/last on PG16

---
 src/planner/agg_bookend.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/planner/agg_bookend.c b/src/planner/agg_bookend.c
index e08eb0986fd..5fe9a32d866 100644
--- a/src/planner/agg_bookend.c
+++ b/src/planner/agg_bookend.c
@@ -60,6 +60,7 @@
 #include <utils/syscache.h>
 #include <utils/typcache.h>
 
+#include "compat/compat.h"
 #include "planner.h"
 #include "utils.h"
 #include "extension.h"
@@ -593,6 +594,9 @@ build_first_last_path(PlannerInfo *root, FirstLastAggInfo *fl_info, Oid eqop, Oi
 	/* and we haven't made equivalence classes, either */
 	Assert(subroot->eq_classes == NIL);
 	/* and we haven't created PlaceHolderInfos, either */
+#if PG16_GE
+	subroot->placeholdersFrozen = false;
+#endif
 	Assert(subroot->placeholder_list == NIL);
 
 	mminfo = fl_info->m_agg_info;