Stabilize query plans in rowsecurity regression test.

Some recent buildfarm failures can be explained by supposing that
autovacuum or autoanalyze fired on the tables created by this test,
resulting in plan changes.  Do a proactive VACUUM ANALYZE on the
test's principal tables to try to forestall such changes.

src/test/regress/expected/rowsecurity.out

@@ -68,6 +68,8 @@ INSERT INTO document VALUES
     ( 6, 22, 1, 'rls_regress_user2', 'great science fiction'),
     ( 7, 33, 2, 'rls_regress_user2', 'great technology book'),
     ( 8, 44, 1, 'rls_regress_user2', 'great manga');
+VACUUM ANALYZE category;
+VACUUM ANALYZE document;
 ALTER TABLE document ENABLE ROW LEVEL SECURITY;
 -- user's security level must be higher than or equal to document's
 CREATE POLICY p1 ON document
@@ -184,20 +186,19 @@ EXPLAIN (COSTS OFF) SELECT * FROM document WHERE f_leak(dtitle);
 (7 rows)
 
 EXPLAIN (COSTS OFF) SELECT * FROM document NATURAL JOIN category WHERE f_leak(dtitle);
-                              QUERY PLAN                              
-----------------------------------------------------------------------
- Hash Join
-   Hash Cond: (category.cid = document.cid)
+                           QUERY PLAN                           
+----------------------------------------------------------------
+ Nested Loop
+   Join Filter: (document.cid = category.cid)
+   ->  Subquery Scan on document
+         Filter: f_leak(document.dtitle)
+         ->  Seq Scan on document document_1
+               Filter: (dlevel <= $0)
+               InitPlan 1 (returns $0)
+                 ->  Index Scan using uaccount_pkey on uaccount
+                       Index Cond: (pguser = "current_user"())
    ->  Seq Scan on category
-   ->  Hash
-         ->  Subquery Scan on document
-               Filter: f_leak(document.dtitle)
-               ->  Seq Scan on document document_1
-                     Filter: (dlevel <= $0)
-                     InitPlan 1 (returns $0)
-                       ->  Index Scan using uaccount_pkey on uaccount
-                             Index Cond: (pguser = "current_user"())
-(11 rows)
+(10 rows)
 
 -- only owner can change policies
 ALTER POLICY p1 ON document USING (true);    --fail
@@ -275,12 +276,12 @@ EXPLAIN (COSTS OFF) SELECT * FROM document NATURAL JOIN category WHERE f_leak(dt
                      QUERY PLAN                     
 ----------------------------------------------------
  Nested Loop
+   Join Filter: (document.cid = category.cid)
    ->  Subquery Scan on document
          Filter: f_leak(document.dtitle)
          ->  Seq Scan on document document_1
                Filter: (dauthor = "current_user"())
-   ->  Index Scan using category_pkey on category
-         Index Cond: (cid = document.cid)
+   ->  Seq Scan on category
 (7 rows)
 
 -- interaction of FK/PK constraints
@@ -295,12 +296,12 @@ SET SESSION AUTHORIZATION rls_regress_user1;
 SELECT * FROM document d FULL OUTER JOIN category c on d.cid = c.cid;
  did | cid | dlevel |      dauthor      |       dtitle       | cid |   cname    
 -----+-----+--------+-------------------+--------------------+-----+------------
-   2 |  11 |      2 | rls_regress_user1 | my second novel    |  11 | novel
    1 |  11 |      1 | rls_regress_user1 | my first novel     |  11 | novel
-     |     |        |                   |                    |  33 | technology
-   5 |  44 |      2 | rls_regress_user1 | my second manga    |     | 
-   4 |  44 |      1 | rls_regress_user1 | my first manga     |     | 
+   2 |  11 |      2 | rls_regress_user1 | my second novel    |  11 | novel
    3 |  22 |      2 | rls_regress_user1 | my science fiction |     | 
+   4 |  44 |      1 | rls_regress_user1 | my first manga     |     | 
+   5 |  44 |      2 | rls_regress_user1 | my second manga    |     | 
+     |     |        |                   |                    |  33 | technology
 (6 rows)
 
 DELETE FROM category WHERE cid = 33;    -- fails with FK violation
@@ -312,8 +313,8 @@ SELECT * FROM document d FULL OUTER JOIN category c on d.cid = c.cid;
  did | cid | dlevel |      dauthor      |        dtitle         | cid |      cname      
 -----+-----+--------+-------------------+-----------------------+-----+-----------------
    6 |  22 |      1 | rls_regress_user2 | great science fiction |  22 | science fiction
-   8 |  44 |      1 | rls_regress_user2 | great manga           |  44 | manga
    7 |  33 |      2 | rls_regress_user2 | great technology book |     | 
+   8 |  44 |      1 | rls_regress_user2 | great manga           |  44 | manga
 (3 rows)
 
 INSERT INTO document VALUES (10, 33, 1, current_user, 'hoge');

src/test/regress/sql/rowsecurity.sql

@@ -82,6 +82,9 @@ INSERT INTO document VALUES
     ( 7, 33, 2, 'rls_regress_user2', 'great technology book'),
     ( 8, 44, 1, 'rls_regress_user2', 'great manga');
 
+VACUUM ANALYZE category;
+VACUUM ANALYZE document;
+
 ALTER TABLE document ENABLE ROW LEVEL SECURITY;
 
 -- user's security level must be higher than or equal to document's