1 files changed, 51 insertions, 0 deletions
diff --git a/contrib/tsm_system_time/sql/tsm_system_time.sql b/contrib/tsm_system_time/sql/tsm_system_time.sql
new file mode 100644
index 0000000..117de16
--- /dev/null
+++ b/contrib/tsm_system_time/sql/tsm_system_time.sql
@@ -0,0 +1,51 @@
+CREATE EXTENSION tsm_system_time;
+
+CREATE TABLE test_tablesample (id int, name text);
+INSERT INTO test_tablesample SELECT i, repeat(i::text, 1000)
+  FROM generate_series(0, 30) s(i);
+ANALYZE test_tablesample;
+
+-- It's a bit tricky to test SYSTEM_TIME in a platform-independent way.
+-- We can test the zero-time corner case ...
+SELECT count(*) FROM test_tablesample TABLESAMPLE system_time (0);
+-- ... and we assume that this will finish before running out of time:
+SELECT count(*) FROM test_tablesample TABLESAMPLE system_time (100000);
+
+-- bad parameters should get through planning, but not execution:
+EXPLAIN (COSTS OFF)
+SELECT id FROM test_tablesample TABLESAMPLE system_time (-1);
+
+SELECT id FROM test_tablesample TABLESAMPLE system_time (-1);
+
+-- fail, this method is not repeatable:
+SELECT * FROM test_tablesample TABLESAMPLE system_time (10) REPEATABLE (0);
+
+-- since it's not repeatable, we expect a Materialize node in these plans:
+EXPLAIN (COSTS OFF)
+SELECT * FROM
+  (VALUES (0),(100000)) v(time),
+  LATERAL (SELECT COUNT(*) FROM test_tablesample
+           TABLESAMPLE system_time (100000)) ss;
+
+SELECT * FROM
+  (VALUES (0),(100000)) v(time),
+  LATERAL (SELECT COUNT(*) FROM test_tablesample
+           TABLESAMPLE system_time (100000)) ss;
+
+EXPLAIN (COSTS OFF)
+SELECT * FROM
+  (VALUES (0),(100000)) v(time),
+  LATERAL (SELECT COUNT(*) FROM test_tablesample
+           TABLESAMPLE system_time (time)) ss;
+
+SELECT * FROM
+  (VALUES (0),(100000)) v(time),
+  LATERAL (SELECT COUNT(*) FROM test_tablesample
+           TABLESAMPLE system_time (time)) ss;
+
+CREATE VIEW vv AS
+  SELECT * FROM test_tablesample TABLESAMPLE system_time (20);
+
+EXPLAIN (COSTS OFF) SELECT * FROM vv;
+
+DROP EXTENSION tsm_system_time;  -- fail, view depends on extension