1 files changed, 30 insertions, 0 deletions
diff --git a/contrib/postgres_fdw/sql/postgres_fdw.sql b/contrib/postgres_fdw/sql/postgres_fdw.sql
index fcfb10d29ea..83e8fa7b045 100644
--- a/contrib/postgres_fdw/sql/postgres_fdw.sql
+++ b/contrib/postgres_fdw/sql/postgres_fdw.sql
@@ -406,6 +406,36 @@ select c2, count(*) from ft2 where c2 < 500 group by 1 order by 1;
 select c2, count(*) from "S 1"."T 1" where c2 < 500 group by 1 order by 1;
 
 -- ===================================================================
+-- test check constraints
+-- ===================================================================
+
+-- Consistent check constraints provide consistent results
+ALTER FOREIGN TABLE ft1 ADD CONSTRAINT ft1_c2positive CHECK (c2 >= 0);
+EXPLAIN (VERBOSE, COSTS false) SELECT count(*) FROM ft1 WHERE c2 < 0;
+SELECT count(*) FROM ft1 WHERE c2 < 0;
+SET constraint_exclusion = 'on';
+EXPLAIN (VERBOSE, COSTS false) SELECT count(*) FROM ft1 WHERE c2 < 0;
+SELECT count(*) FROM ft1 WHERE c2 < 0;
+RESET constraint_exclusion;
+-- check constraint is enforced on the remote side, not locally
+INSERT INTO ft1(c1, c2) VALUES(1111, -2);  -- c2positive
+UPDATE ft1 SET c2 = -c2 WHERE c1 = 1;  -- c2positive
+ALTER FOREIGN TABLE ft1 DROP CONSTRAINT ft1_c2positive;
+
+-- But inconsistent check constraints provide inconsistent results
+ALTER FOREIGN TABLE ft1 ADD CONSTRAINT ft1_c2negative CHECK (c2 < 0);
+EXPLAIN (VERBOSE, COSTS false) SELECT count(*) FROM ft1 WHERE c2 >= 0;
+SELECT count(*) FROM ft1 WHERE c2 >= 0;
+SET constraint_exclusion = 'on';
+EXPLAIN (VERBOSE, COSTS false) SELECT count(*) FROM ft1 WHERE c2 >= 0;
+SELECT count(*) FROM ft1 WHERE c2 >= 0;
+RESET constraint_exclusion;
+-- local check constraint is not actually enforced
+INSERT INTO ft1(c1, c2) VALUES(1111, 2);
+UPDATE ft1 SET c2 = c2 + 1 WHERE c1 = 1;
+ALTER FOREIGN TABLE ft1 DROP CONSTRAINT ft1_c2negative;
+
+-- ===================================================================
 -- test serial columns (ie, sequence-based defaults)
 -- ===================================================================
 create table loc1 (f1 serial, f2 text);