1 files changed, 83 insertions, 0 deletions
diff --git a/contrib/tsm_system_rows/expected/tsm_system_rows.out b/contrib/tsm_system_rows/expected/tsm_system_rows.out
new file mode 100644
index 0000000..87b4a8f
--- /dev/null
+++ b/contrib/tsm_system_rows/expected/tsm_system_rows.out
@@ -0,0 +1,83 @@
+CREATE EXTENSION tsm_system_rows;
+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;
+SELECT count(*) FROM test_tablesample TABLESAMPLE system_rows (0);
+ count 
+-------
+     0
+(1 row)
+
+SELECT count(*) FROM test_tablesample TABLESAMPLE system_rows (1);
+ count 
+-------
+     1
+(1 row)
+
+SELECT count(*) FROM test_tablesample TABLESAMPLE system_rows (10);
+ count 
+-------
+    10
+(1 row)
+
+SELECT count(*) FROM test_tablesample TABLESAMPLE system_rows (100);
+ count 
+-------
+    31
+(1 row)
+
+-- bad parameters should get through planning, but not execution:
+EXPLAIN (COSTS OFF)
+SELECT id FROM test_tablesample TABLESAMPLE system_rows (-1);
+               QUERY PLAN               
+----------------------------------------
+ Sample Scan on test_tablesample
+   Sampling: system_rows ('-1'::bigint)
+(2 rows)
+
+SELECT id FROM test_tablesample TABLESAMPLE system_rows (-1);
+ERROR:  sample size must not be negative
+-- fail, this method is not repeatable:
+SELECT * FROM test_tablesample TABLESAMPLE system_rows (10) REPEATABLE (0);
+ERROR:  tablesample method system_rows does not support REPEATABLE
+LINE 1: SELECT * FROM test_tablesample TABLESAMPLE system_rows (10) ...
+                                                   ^
+-- but a join should be allowed:
+EXPLAIN (COSTS OFF)
+SELECT * FROM
+  (VALUES (0),(10),(100)) v(nrows),
+  LATERAL (SELECT count(*) FROM test_tablesample
+           TABLESAMPLE system_rows (nrows)) ss;
+                        QUERY PLAN                        
+----------------------------------------------------------
+ Nested Loop
+   ->  Values Scan on "*VALUES*"
+   ->  Aggregate
+         ->  Sample Scan on test_tablesample
+               Sampling: system_rows ("*VALUES*".column1)
+(5 rows)
+
+SELECT * FROM
+  (VALUES (0),(10),(100)) v(nrows),
+  LATERAL (SELECT count(*) FROM test_tablesample
+           TABLESAMPLE system_rows (nrows)) ss;
+ nrows | count 
+-------+-------
+     0 |     0
+    10 |    10
+   100 |    31
+(3 rows)
+
+CREATE VIEW vv AS
+  SELECT count(*) FROM test_tablesample TABLESAMPLE system_rows (20);
+SELECT * FROM vv;
+ count 
+-------
+    20
+(1 row)
+
+DROP EXTENSION tsm_system_rows;  -- fail, view depends on extension
+ERROR:  cannot drop extension tsm_system_rows because other objects depend on it
+DETAIL:  view vv depends on function system_rows(internal)
+HINT:  Use DROP ... CASCADE to drop the dependent objects too.