diff -U3 /tmp/cirrus-ci-build/src/test/regress/expected/partition_join.out /tmp/cirrus-ci-build/src/bin/pg_upgrade/tmp_check/results/partition_join.out
--- /tmp/cirrus-ci-build/src/test/regress/expected/partition_join.out	2024-04-24 02:37:42.170974547 +0000
+++ /tmp/cirrus-ci-build/src/bin/pg_upgrade/tmp_check/results/partition_join.out	2024-04-24 02:41:33.542987147 +0000
@@ -5133,17 +5133,15 @@
                               QUERY PLAN                               
 -----------------------------------------------------------------------
  Limit
-   ->  Merge Append
-         Sort Key: x.id
-         ->  Merge Left Join
-               Merge Cond: (x_1.id = y_1.id)
+   ->  Merge Left Join
+         Merge Cond: (x.id = y.id)
+         ->  Append
                ->  Index Only Scan using fract_t0_pkey on fract_t0 x_1
-               ->  Index Only Scan using fract_t0_pkey on fract_t0 y_1
-         ->  Merge Left Join
-               Merge Cond: (x_2.id = y_2.id)
                ->  Index Only Scan using fract_t1_pkey on fract_t1 x_2
+         ->  Append
+               ->  Index Only Scan using fract_t0_pkey on fract_t0 y_1
                ->  Index Only Scan using fract_t1_pkey on fract_t1 y_2
-(11 rows)
+(9 rows)
 
 EXPLAIN (COSTS OFF)
 SELECT x.id, y.id FROM fract_t x LEFT JOIN fract_t y USING (id) ORDER BY x.id DESC LIMIT 10;