Remove dependency to pg_stat_statements in regression tests

pg_stat_statements was still being used for a few tests in pg_hint_plan,
with most of the cases removed by 32ced2e.  The remaining cases
involve:
- Check that relations parts of extensions are not affected by hints,
which has a limited interest.
- pg_stat_statements_reset() combined with a scan of pg_stat_statements,
which has also limited interest because upstream covers that already, in
a much wider way.

As a whole, this dependency does not provide any meaningful coverage not
covered by upstream, and now that query IDs are used in the hint table,
even less.  This commit removes the dependency altogether, making it
possible to run the regression test suite without these binaries
installed.

expected/init.out

@@ -143,8 +143,7 @@ CREATE VIEW v4 AS SELECT v_2.t1_id, t_3.id FROM v2 v_2, t3 t_3 WHERE v_2.t1_id =
  * Utility function to retrieve a query ID from a query.
  *
  * This wraps the input query within an EXPLAIN (VERBOSE, FORMAT json) and
- * returns its query ID.  This removes the need to use pg_stat_statements
- * while minimizing the number of queries executed.
+ * returns its query ID.
  */
 CREATE FUNCTION get_query_id(text) RETURNS bigint
 LANGUAGE plpgsql AS

expected/ut-A.out

@@ -3147,12 +3147,6 @@ SHOW pg_hint_plan.debug_print;
 ---- No. A-11-5 EXECUTE statement name error
 ----
 -- No. A-11-5-1
-SELECT pg_stat_statements_reset() IS NOT NULL as t;
- t 
----
- t
-(1 row)
-
 SELECT * FROM s1.t1 WHERE t1.c1 = 1;
  c1 | c2 | c3 | c4 
 ----+----+----+----
@@ -3185,17 +3179,6 @@ error hint:
   1 |  1 |  1 | 1
 (1 row)
 
-SELECT s.query, s.calls
-  FROM public.pg_stat_statements s
-  JOIN pg_catalog.pg_database d
-    ON (s.dbid = d.oid)
- ORDER BY 1;
-                       query                        | calls 
-----------------------------------------------------+-------
- SELECT * FROM s1.t1 WHERE t1.c1 = $1               |     3
- SELECT pg_stat_statements_reset() IS NOT NULL as t |     1
-(2 rows)
-
 ----
 ---- No. A-12-1 reset of global variable of core at the error
 ---- No. A-12-2 reset of global variable of original at the error

expected/ut-W.out

@@ -1248,24 +1248,21 @@ Parallel()
 
 -- Hints on unhintable relations are just ignored
 /*+Parallel(p1 5 hard) Parallel(s1 3 hard) IndexScan(ft1) SeqScan(cte1)
-  TidScan(fs1) IndexScan(t) IndexScan(*VALUES*) */
+  IndexScan(t) IndexScan(*VALUES*) */
 \o results/ut-W.tmpout
 EXPLAIN (COSTS false) SELECT id FROM p1_c1_c1 as s1 TABLESAMPLE SYSTEM(10)
  UNION ALL
 SELECT id FROM ft1
  UNION ALL
 (WITH cte1 AS (SELECT id FROM p1 WHERE id % 2 = 0) SELECT id FROM cte1)
  UNION ALL
-SELECT userid FROM pg_stat_statements fs1
- UNION ALL
 SELECT x FROM (VALUES (1), (2), (3)) t(x);
 LOG:  pg_hint_plan:
 used hint:
 Parallel(p1 5 hard)
 not used hint:
 IndexScan(*VALUES*)
 SeqScan(cte1)
-TidScan(fs1)
 IndexScan(ft1)
 IndexScan(t)
 Parallel(s1 3 hard)
@@ -1276,38 +1273,35 @@ error hint:
 \! sql/maskout2.sh results/ut-W.tmpout
 --(snip..)
 --(snip..)
- Append
-   ->  Result
-         ->  Append
-               ->  Sample Scan on p1_c1_c1 s1
-                     Sampling: system ('10'::real)
-               ->  Foreign Scan on ft1
-                     Foreign File:  (snip..)
-               ->  Gather
-                     Workers Planned: 5
-                     ->  Parallel Append
-                           ->  Seq Scan on p1 p1_1
-                                 Filter: ((id % 2) = 0)
-                           ->  Seq Scan on p1_c1 p1_2
-                                 Filter: ((id % 2) = 0)
-                           ->  Seq Scan on p1_c3 p1_4
-                                 Filter: ((id % 2) = 0)
-                           ->  Parallel Seq Scan on p1_c2 p1_3
-                                 Filter: ((id % 2) = 0)
-                           ->  Parallel Seq Scan on p1_c4 p1_5
-                                 Filter: ((id % 2) = 0)
-                           ->  Parallel Seq Scan on p1_c1_c1 p1_6
-                                 Filter: ((id % 2) = 0)
-                           ->  Parallel Seq Scan on p1_c1_c2 p1_7
-                                 Filter: ((id % 2) = 0)
-                           ->  Parallel Seq Scan on p1_c3_c1 p1_8
-                                 Filter: ((id % 2) = 0)
-                           ->  Parallel Seq Scan on p1_c3_c2 p1_9
-                                 Filter: ((id % 2) = 0)
-   ->  Function Scan on pg_stat_statements
-   ->  Subquery Scan on "*SELECT* 5"
+ Gather
+   Workers Planned: 1
+   Single Copy: true
+   ->  Parallel Append
+         ->  Sample Scan on p1_c1_c1 s1
+               Sampling: system ('10'::real)
+         ->  Foreign Scan on ft1
+               Foreign File:  (snip..)
          ->  Values Scan on "*VALUES*"
-(31 rows)
+         ->  Parallel Append
+               ->  Seq Scan on p1 p1_1
+                     Filter: ((id % 2) = 0)
+               ->  Seq Scan on p1_c1 p1_2
+                     Filter: ((id % 2) = 0)
+               ->  Seq Scan on p1_c3 p1_4
+                     Filter: ((id % 2) = 0)
+               ->  Parallel Seq Scan on p1_c2 p1_3
+                     Filter: ((id % 2) = 0)
+               ->  Parallel Seq Scan on p1_c4 p1_5
+                     Filter: ((id % 2) = 0)
+               ->  Parallel Seq Scan on p1_c1_c1 p1_6
+                     Filter: ((id % 2) = 0)
+               ->  Parallel Seq Scan on p1_c1_c2 p1_7
+                     Filter: ((id % 2) = 0)
+               ->  Parallel Seq Scan on p1_c3_c1 p1_8
+                     Filter: ((id % 2) = 0)
+               ->  Parallel Seq Scan on p1_c3_c2 p1_9
+                     Filter: ((id % 2) = 0)
+(28 rows)
 
 ALTER SYSTEM SET session_preload_libraries TO DEFAULT;
 SELECT pg_reload_conf();

expected/ut-init.out

@@ -1,5 +1,4 @@
 SET search_path TO public;
-CREATE EXTENSION pg_stat_statements;
 CREATE EXTENSION btree_gist;
 CREATE EXTENSION btree_gin;
 CREATE ROLE regress_super_user

sql/init.sql

@@ -118,8 +118,7 @@ CREATE VIEW v4 AS SELECT v_2.t1_id, t_3.id FROM v2 v_2, t3 t_3 WHERE v_2.t1_id =
  * Utility function to retrieve a query ID from a query.
  *
  * This wraps the input query within an EXPLAIN (VERBOSE, FORMAT json) and
- * returns its query ID.  This removes the need to use pg_stat_statements
- * while minimizing the number of queries executed.
+ * returns its query ID.
  */
 CREATE FUNCTION get_query_id(text) RETURNS bigint
 LANGUAGE plpgsql AS

sql/ut-A.sql

@@ -926,15 +926,9 @@ SHOW pg_hint_plan.debug_print;
 ----
 
 -- No. A-11-5-1
-SELECT pg_stat_statements_reset() IS NOT NULL as t;
 SELECT * FROM s1.t1 WHERE t1.c1 = 1;
 /*+Set(enable_seqscan off)*/ SELECT * FROM s1.t1 WHERE t1.c1 = 1;
 /*+SeqScan(t1)*/ SELECT * FROM s1.t1 WHERE t1.c1 = 1;
-SELECT s.query, s.calls
-  FROM public.pg_stat_statements s
-  JOIN pg_catalog.pg_database d
-    ON (s.dbid = d.oid)
- ORDER BY 1;
 
 ----
 ---- No. A-12-1 reset of global variable of core at the error

sql/ut-W.sql

@@ -207,16 +207,14 @@ EXPLAIN (COSTS false) SELECT id FROM p1 UNION ALL SELECT id FROM p2;
 
 -- Hints on unhintable relations are just ignored
 /*+Parallel(p1 5 hard) Parallel(s1 3 hard) IndexScan(ft1) SeqScan(cte1)
-  TidScan(fs1) IndexScan(t) IndexScan(*VALUES*) */
+  IndexScan(t) IndexScan(*VALUES*) */
 \o results/ut-W.tmpout
 EXPLAIN (COSTS false) SELECT id FROM p1_c1_c1 as s1 TABLESAMPLE SYSTEM(10)
  UNION ALL
 SELECT id FROM ft1
  UNION ALL
 (WITH cte1 AS (SELECT id FROM p1 WHERE id % 2 = 0) SELECT id FROM cte1)
  UNION ALL
-SELECT userid FROM pg_stat_statements fs1
- UNION ALL
 SELECT x FROM (VALUES (1), (2), (3)) t(x);
 \o
 \! sql/maskout2.sh results/ut-W.tmpout

sql/ut-init.sql

@@ -1,6 +1,5 @@
 SET search_path TO public;
 
-CREATE EXTENSION pg_stat_statements;
 CREATE EXTENSION btree_gist;
 CREATE EXTENSION btree_gin;