1 files changed, 40 insertions, 0 deletions
diff --git a/contrib/postgres_fdw/sql/postgres_fdw.sql b/contrib/postgres_fdw/sql/postgres_fdw.sql
index 671e38ceaa3..73fa9f6de09 100644
--- a/contrib/postgres_fdw/sql/postgres_fdw.sql
+++ b/contrib/postgres_fdw/sql/postgres_fdw.sql
@@ -178,6 +178,20 @@ SELECT * FROM ft1 t1 WHERE t1.c3 = (SELECT MAX(c3) FROM ft2 t2) ORDER BY c1;
 WITH t1 AS (SELECT * FROM ft1 WHERE c1 <= 10) SELECT t2.c1, t2.c2, t2.c3, t2.c4 FROM t1, ft2 t2 WHERE t1.c1 = t2.c1 ORDER BY t1.c1;
 -- fixed values
 SELECT 'fixed', NULL FROM ft1 t1 WHERE c1 = 1;
+-- Test forcing the remote server to produce sorted data for a merge join.
+SET enable_hashjoin TO false;
+SET enable_nestloop TO false;
+-- inner join; expressions in the clauses appear in the equivalence class list
+EXPLAIN (VERBOSE, COSTS false)
+	SELECT t1.c1, t2."C 1" FROM ft2 t1 JOIN "S 1"."T 1" t2 ON (t1.c1 = t2."C 1") OFFSET 100 LIMIT 10;
+SELECT t1.c1, t2."C 1" FROM ft2 t1 JOIN "S 1"."T 1" t2 ON (t1.c1 = t2."C 1") OFFSET 100 LIMIT 10;
+-- outer join; expressions in the clauses do not appear in equivalence class
+-- list but no output change as compared to the previous query
+EXPLAIN (VERBOSE, COSTS false)
+	SELECT t1.c1, t2."C 1" FROM ft2 t1 LEFT JOIN "S 1"."T 1" t2 ON (t1.c1 = t2."C 1") OFFSET 100 LIMIT 10;
+SELECT t1.c1, t2."C 1" FROM ft2 t1 LEFT JOIN "S 1"."T 1" t2 ON (t1.c1 = t2."C 1") OFFSET 100 LIMIT 10;
+RESET enable_hashjoin;
+RESET enable_nestloop;
 
 -- ===================================================================
 -- WHERE with remotely-executable conditions
@@ -812,6 +826,32 @@ where bar.f1 = ss.f1;
 
 select tableoid::regclass, * from bar order by 1,2;
 
+-- Test forcing the remote server to produce sorted data for a merge join,
+-- but the foreign table is an inheritance child.
+truncate table loct1;
+truncate table only foo;
+\set num_rows_foo 2000
+insert into loct1 select generate_series(0, :num_rows_foo, 2), generate_series(0, :num_rows_foo, 2), generate_series(0, :num_rows_foo, 2);
+insert into foo select generate_series(1, :num_rows_foo, 2), generate_series(1, :num_rows_foo, 2);
+SET enable_hashjoin to false;
+SET enable_nestloop to false;
+alter foreign table foo2 options (use_remote_estimate 'true');
+create index i_loct1_f1 on loct1(f1);
+create index i_foo_f1 on foo(f1);
+analyze foo;
+analyze loct1;
+-- inner join; expressions in the clauses appear in the equivalence class list
+explain (verbose, costs off)
+	select foo.f1, loct1.f1 from foo join loct1 on (foo.f1 = loct1.f1) order by foo.f2 offset 10 limit 10;
+select foo.f1, loct1.f1 from foo join loct1 on (foo.f1 = loct1.f1) order by foo.f2 offset 10 limit 10;
+-- outer join; expressions in the clauses do not appear in equivalence class
+-- list but no output change as compared to the previous query
+explain (verbose, costs off)
+	select foo.f1, loct1.f1 from foo left join loct1 on (foo.f1 = loct1.f1) order by foo.f2 offset 10 limit 10;
+select foo.f1, loct1.f1 from foo left join loct1 on (foo.f1 = loct1.f1) order by foo.f2 offset 10 limit 10;
+RESET enable_hashjoin;
+RESET enable_nestloop;
+
 -- Test that WHERE CURRENT OF is not supported
 begin;
 declare c cursor for select * from bar where f1 = 7;