Fix test case for 'outer pathkeys do not match mergeclauses' fix.

Commit 4bbf6edf added a test case,
but it turns out that the test case doesn't reliably test for the
bug, and in the context of the regression test suite did not because
ANALYZE had not been run.

Report and patch by Etsuro Fujita.  I added a comment along lines
previously suggested by Tom Lane.

Discussion: http://postgr.es/m/5A6195D8.8060206@lab.ntt.co.jp

contrib/postgres_fdw/expected/postgres_fdw.out

@@ -2330,23 +2330,29 @@ SELECT ft5, ft5.c1, ft5.c2, ft5.c3, ft4.c1, ft4.c2 FROM ft5 left join ft4 on ft5
 (4 rows)
 
 -- multi-way join involving multiple merge joins
+-- (this case used to have EPQ-related planning problems)
+SET enable_nestloop TO false;
+SET enable_hashjoin TO false;
 EXPLAIN (VERBOSE, COSTS OFF)
-SELECT * FROM ft1, ft2, ft4, ft5 WHERE ft1.c1 = ft2.c1 AND ft1.c1 = ft4.c1
-    AND ft1.c1 = ft5.c1 FOR UPDATE;
+SELECT * FROM ft1, ft2, ft4, ft5 WHERE ft1.c1 = ft2.c1 AND ft1.c2 = ft4.c1
+    AND ft1.c2 = ft5.c1 AND ft1.c1 < 100 AND ft2.c1 < 100 FOR UPDATE;
                                                                                                                                                                                                                                                                                                                                                                                                                              QUERY PLAN                                                                                                                                                                                                                                                                                                                                                                                                                             
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
  LockRows
    Output: ft1.c1, ft1.c2, ft1.c3, ft1.c4, ft1.c5, ft1.c6, ft1.c7, ft1.c8, ft2.c1, ft2.c2, ft2.c3, ft2.c4, ft2.c5, ft2.c6, ft2.c7, ft2.c8, ft4.c1, ft4.c2, ft4.c3, ft5.c1, ft5.c2, ft5.c3, ft1.*, ft2.*, ft4.*, ft5.*
    ->  Foreign Scan
          Output: ft1.c1, ft1.c2, ft1.c3, ft1.c4, ft1.c5, ft1.c6, ft1.c7, ft1.c8, ft2.c1, ft2.c2, ft2.c3, ft2.c4, ft2.c5, ft2.c6, ft2.c7, ft2.c8, ft4.c1, ft4.c2, ft4.c3, ft5.c1, ft5.c2, ft5.c3, ft1.*, ft2.*, ft4.*, ft5.*
          Relations: (((public.ft1) INNER JOIN (public.ft2)) INNER JOIN (public.ft4)) INNER JOIN (public.ft5)
-         Remote SQL: SELECT r1."C 1", r1.c2, r1.c3, r1.c4, r1.c5, r1.c6, r1.c7, r1.c8, CASE WHEN (r1.*)::text IS NOT NULL THEN ROW(r1."C 1", r1.c2, r1.c3, r1.c4, r1.c5, r1.c6, r1.c7, r1.c8) END, r2."C 1", r2.c2, r2.c3, r2.c4, r2.c5, r2.c6, r2.c7, r2.c8, CASE WHEN (r2.*)::text IS NOT NULL THEN ROW(r2."C 1", r2.c2, r2.c3, r2.c4, r2.c5, r2.c6, r2.c7, r2.c8) END, r3.c1, r3.c2, r3.c3, CASE WHEN (r3.*)::text IS NOT NULL THEN ROW(r3.c1, r3.c2, r3.c3) END, r4.c1, r4.c2, r4.c3, CASE WHEN (r4.*)::text IS NOT NULL THEN ROW(r4.c1, r4.c2, r4.c3) END FROM ((("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")))) INNER JOIN "S 1"."T 3" r3 ON (((r1."C 1" = r3.c1)))) INNER JOIN "S 1"."T 4" r4 ON (((r1."C 1" = r4.c1)))) FOR UPDATE OF r1 FOR UPDATE OF r2 FOR UPDATE OF r3 FOR UPDATE OF r4
+         Remote SQL: SELECT r1."C 1", r1.c2, r1.c3, r1.c4, r1.c5, r1.c6, r1.c7, r1.c8, CASE WHEN (r1.*)::text IS NOT NULL THEN ROW(r1."C 1", r1.c2, r1.c3, r1.c4, r1.c5, r1.c6, r1.c7, r1.c8) END, r2."C 1", r2.c2, r2.c3, r2.c4, r2.c5, r2.c6, r2.c7, r2.c8, CASE WHEN (r2.*)::text IS NOT NULL THEN ROW(r2."C 1", r2.c2, r2.c3, r2.c4, r2.c5, r2.c6, r2.c7, r2.c8) END, r3.c1, r3.c2, r3.c3, CASE WHEN (r3.*)::text IS NOT NULL THEN ROW(r3.c1, r3.c2, r3.c3) END, r4.c1, r4.c2, r4.c3, CASE WHEN (r4.*)::text IS NOT NULL THEN ROW(r4.c1, r4.c2, r4.c3) END FROM ((("S 1"."T 1" r1 INNER JOIN "S 1"."T 1" r2 ON (((r1."C 1" = r2."C 1")) AND ((r2."C 1" < 100)) AND ((r1."C 1" < 100)))) INNER JOIN "S 1"."T 3" r3 ON (((r1.c2 = r3.c1)))) INNER JOIN "S 1"."T 4" r4 ON (((r1.c2 = r4.c1)))) FOR UPDATE OF r1 FOR UPDATE OF r2 FOR UPDATE OF r3 FOR UPDATE OF r4
          ->  Merge Join
                Output: ft1.c1, ft1.c2, ft1.c3, ft1.c4, ft1.c5, ft1.c6, ft1.c7, ft1.c8, ft1.*, ft2.c1, ft2.c2, ft2.c3, ft2.c4, ft2.c5, ft2.c6, ft2.c7, ft2.c8, ft2.*, ft4.c1, ft4.c2, ft4.c3, ft4.*, ft5.c1, ft5.c2, ft5.c3, ft5.*
-               Merge Cond: (ft1.c1 = ft5.c1)
+               Merge Cond: (ft1.c2 = ft5.c1)
                ->  Merge Join
                      Output: ft1.c1, ft1.c2, ft1.c3, ft1.c4, ft1.c5, ft1.c6, ft1.c7, ft1.c8, ft1.*, ft2.c1, ft2.c2, ft2.c3, ft2.c4, ft2.c5, ft2.c6, ft2.c7, ft2.c8, ft2.*, ft4.c1, ft4.c2, ft4.c3, ft4.*
-                     Merge Cond: (ft1.c1 = ft4.c1)
+                     Merge Cond: (ft1.c2 = ft4.c1)
+                     ->  Sort
+                           Output: ft1.c1, ft1.c2, ft1.c3, ft1.c4, ft1.c5, ft1.c6, ft1.c7, ft1.c8, ft1.*, ft2.c1, ft2.c2, ft2.c3, ft2.c4, ft2.c5, ft2.c6, ft2.c7, ft2.c8, ft2.*
+                           Sort Key: ft1.c2
                            ->  Merge Join
                                  Output: ft1.c1, ft1.c2, ft1.c3, ft1.c4, ft1.c5, ft1.c6, ft1.c7, ft1.c8, ft1.*, ft2.c1, ft2.c2, ft2.c3, ft2.c4, ft2.c5, ft2.c6, ft2.c7, ft2.c8, ft2.*
                                  Merge Cond: (ft1.c1 = ft2.c1)
@@ -2355,13 +2361,12 @@ SELECT * FROM ft1, ft2, ft4, ft5 WHERE ft1.c1 = ft2.c1 AND ft1.c1 = ft4.c1
                                        Sort Key: ft1.c1
                                        ->  Foreign Scan on public.ft1
                                              Output: ft1.c1, ft1.c2, ft1.c3, ft1.c4, ft1.c5, ft1.c6, ft1.c7, ft1.c8, ft1.*
-                                       Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" FOR UPDATE
-                           ->  Sort
+                                             Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" WHERE (("C 1" < 100)) FOR UPDATE
+                                 ->  Materialize
                                        Output: ft2.c1, ft2.c2, ft2.c3, ft2.c4, ft2.c5, ft2.c6, ft2.c7, ft2.c8, ft2.*
-                                 Sort Key: ft2.c1
                                        ->  Foreign Scan on public.ft2
                                              Output: ft2.c1, ft2.c2, ft2.c3, ft2.c4, ft2.c5, ft2.c6, ft2.c7, ft2.c8, ft2.*
-                                       Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" FOR UPDATE
+                                             Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8 FROM "S 1"."T 1" WHERE (("C 1" < 100)) ORDER BY "C 1" ASC NULLS LAST FOR UPDATE
                      ->  Sort
                            Output: ft4.c1, ft4.c2, ft4.c3, ft4.*
                            Sort Key: ft4.c1
@@ -2374,30 +2379,26 @@ SELECT * FROM ft1, ft2, ft4, ft5 WHERE ft1.c1 = ft2.c1 AND ft1.c1 = ft4.c1
                      ->  Foreign Scan on public.ft5
                            Output: ft5.c1, ft5.c2, ft5.c3, ft5.*
                            Remote SQL: SELECT c1, c2, c3 FROM "S 1"."T 4" FOR UPDATE
-(39 rows)
+(41 rows)
 
-SELECT * FROM ft1, ft2, ft4, ft5 WHERE ft1.c1 = ft2.c1 AND ft1.c1 = ft4.c1
-    AND ft1.c1 = ft5.c1 FOR UPDATE;
+SELECT * FROM ft1, ft2, ft4, ft5 WHERE ft1.c1 = ft2.c1 AND ft1.c2 = ft4.c1
+    AND ft1.c2 = ft5.c1 AND ft1.c1 < 100 AND ft2.c1 < 100 FOR UPDATE;
  c1 | c2 |  c3   |              c4              |            c5            | c6 |     c7     | c8  | c1 | c2 |  c3   |              c4              |            c5            | c6 |     c7     | c8  | c1 | c2 |   c3   | c1 | c2 |   c3   
 ----+----+-------+------------------------------+--------------------------+----+------------+-----+----+----+-------+------------------------------+--------------------------+----+------------+-----+----+----+--------+----+----+--------
   6 |  6 | 00006 | Wed Jan 07 00:00:00 1970 PST | Wed Jan 07 00:00:00 1970 | 6  | 6          | foo |  6 |  6 | 00006 | Wed Jan 07 00:00:00 1970 PST | Wed Jan 07 00:00:00 1970 | 6  | 6          | foo |  6 |  7 | AAA006 |  6 |  7 | AAA006
- 12 |  2 | 00012 | Tue Jan 13 00:00:00 1970 PST | Tue Jan 13 00:00:00 1970 | 2  | 2          | foo | 12 |  2 | 00012 | Tue Jan 13 00:00:00 1970 PST | Tue Jan 13 00:00:00 1970 | 2  | 2          | foo | 12 | 13 | AAA012 | 12 | 13 | AAA012
- 18 |  8 | 00018 | Mon Jan 19 00:00:00 1970 PST | Mon Jan 19 00:00:00 1970 | 8  | 8          | foo | 18 |  8 | 00018 | Mon Jan 19 00:00:00 1970 PST | Mon Jan 19 00:00:00 1970 | 8  | 8          | foo | 18 | 19 | AAA018 | 18 | 19 | 
- 24 |  4 | 00024 | Sun Jan 25 00:00:00 1970 PST | Sun Jan 25 00:00:00 1970 | 4  | 4          | foo | 24 |  4 | 00024 | Sun Jan 25 00:00:00 1970 PST | Sun Jan 25 00:00:00 1970 | 4  | 4          | foo | 24 | 25 | AAA024 | 24 | 25 | AAA024
- 30 |  0 | 00030 | Sat Jan 31 00:00:00 1970 PST | Sat Jan 31 00:00:00 1970 | 0  | 0          | foo | 30 |  0 | 00030 | Sat Jan 31 00:00:00 1970 PST | Sat Jan 31 00:00:00 1970 | 0  | 0          | foo | 30 | 31 | AAA030 | 30 | 31 | AAA030
- 36 |  6 | 00036 | Fri Feb 06 00:00:00 1970 PST | Fri Feb 06 00:00:00 1970 | 6  | 6          | foo | 36 |  6 | 00036 | Fri Feb 06 00:00:00 1970 PST | Fri Feb 06 00:00:00 1970 | 6  | 6          | foo | 36 | 37 | AAA036 | 36 | 37 | 
- 42 |  2 | 00042 | Thu Feb 12 00:00:00 1970 PST | Thu Feb 12 00:00:00 1970 | 2  | 2          | foo | 42 |  2 | 00042 | Thu Feb 12 00:00:00 1970 PST | Thu Feb 12 00:00:00 1970 | 2  | 2          | foo | 42 | 43 | AAA042 | 42 | 43 | AAA042
- 48 |  8 | 00048 | Wed Feb 18 00:00:00 1970 PST | Wed Feb 18 00:00:00 1970 | 8  | 8          | foo | 48 |  8 | 00048 | Wed Feb 18 00:00:00 1970 PST | Wed Feb 18 00:00:00 1970 | 8  | 8          | foo | 48 | 49 | AAA048 | 48 | 49 | AAA048
- 54 |  4 | 00054 | Tue Feb 24 00:00:00 1970 PST | Tue Feb 24 00:00:00 1970 | 4  | 4          | foo | 54 |  4 | 00054 | Tue Feb 24 00:00:00 1970 PST | Tue Feb 24 00:00:00 1970 | 4  | 4          | foo | 54 | 55 | AAA054 | 54 | 55 | 
- 60 |  0 | 00060 | Mon Mar 02 00:00:00 1970 PST | Mon Mar 02 00:00:00 1970 | 0  | 0          | foo | 60 |  0 | 00060 | Mon Mar 02 00:00:00 1970 PST | Mon Mar 02 00:00:00 1970 | 0  | 0          | foo | 60 | 61 | AAA060 | 60 | 61 | AAA060
- 66 |  6 | 00066 | Sun Mar 08 00:00:00 1970 PST | Sun Mar 08 00:00:00 1970 | 6  | 6          | foo | 66 |  6 | 00066 | Sun Mar 08 00:00:00 1970 PST | Sun Mar 08 00:00:00 1970 | 6  | 6          | foo | 66 | 67 | AAA066 | 66 | 67 | AAA066
- 72 |  2 | 00072 | Sat Mar 14 00:00:00 1970 PST | Sat Mar 14 00:00:00 1970 | 2  | 2          | foo | 72 |  2 | 00072 | Sat Mar 14 00:00:00 1970 PST | Sat Mar 14 00:00:00 1970 | 2  | 2          | foo | 72 | 73 | AAA072 | 72 | 73 | 
- 78 |  8 | 00078 | Fri Mar 20 00:00:00 1970 PST | Fri Mar 20 00:00:00 1970 | 8  | 8          | foo | 78 |  8 | 00078 | Fri Mar 20 00:00:00 1970 PST | Fri Mar 20 00:00:00 1970 | 8  | 8          | foo | 78 | 79 | AAA078 | 78 | 79 | AAA078
- 84 |  4 | 00084 | Thu Mar 26 00:00:00 1970 PST | Thu Mar 26 00:00:00 1970 | 4  | 4          | foo | 84 |  4 | 00084 | Thu Mar 26 00:00:00 1970 PST | Thu Mar 26 00:00:00 1970 | 4  | 4          | foo | 84 | 85 | AAA084 | 84 | 85 | AAA084
- 90 |  0 | 00090 | Wed Apr 01 00:00:00 1970 PST | Wed Apr 01 00:00:00 1970 | 0  | 0          | foo | 90 |  0 | 00090 | Wed Apr 01 00:00:00 1970 PST | Wed Apr 01 00:00:00 1970 | 0  | 0          | foo | 90 | 91 | AAA090 | 90 | 91 | 
- 96 |  6 | 00096 | Tue Apr 07 00:00:00 1970 PST | Tue Apr 07 00:00:00 1970 | 6  | 6          | foo | 96 |  6 | 00096 | Tue Apr 07 00:00:00 1970 PST | Tue Apr 07 00:00:00 1970 | 6  | 6          | foo | 96 | 97 | AAA096 | 96 | 97 | AAA096
-(16 rows)
+ 16 |  6 | 00016 | Sat Jan 17 00:00:00 1970 PST | Sat Jan 17 00:00:00 1970 | 6  | 6          | foo | 16 |  6 | 00016 | Sat Jan 17 00:00:00 1970 PST | Sat Jan 17 00:00:00 1970 | 6  | 6          | foo |  6 |  7 | AAA006 |  6 |  7 | AAA006
+ 26 |  6 | 00026 | Tue Jan 27 00:00:00 1970 PST | Tue Jan 27 00:00:00 1970 | 6  | 6          | foo | 26 |  6 | 00026 | Tue Jan 27 00:00:00 1970 PST | Tue Jan 27 00:00:00 1970 | 6  | 6          | foo |  6 |  7 | AAA006 |  6 |  7 | AAA006
+ 36 |  6 | 00036 | Fri Feb 06 00:00:00 1970 PST | Fri Feb 06 00:00:00 1970 | 6  | 6          | foo | 36 |  6 | 00036 | Fri Feb 06 00:00:00 1970 PST | Fri Feb 06 00:00:00 1970 | 6  | 6          | foo |  6 |  7 | AAA006 |  6 |  7 | AAA006
+ 46 |  6 | 00046 | Mon Feb 16 00:00:00 1970 PST | Mon Feb 16 00:00:00 1970 | 6  | 6          | foo | 46 |  6 | 00046 | Mon Feb 16 00:00:00 1970 PST | Mon Feb 16 00:00:00 1970 | 6  | 6          | foo |  6 |  7 | AAA006 |  6 |  7 | AAA006
+ 56 |  6 | 00056 | Thu Feb 26 00:00:00 1970 PST | Thu Feb 26 00:00:00 1970 | 6  | 6          | foo | 56 |  6 | 00056 | Thu Feb 26 00:00:00 1970 PST | Thu Feb 26 00:00:00 1970 | 6  | 6          | foo |  6 |  7 | AAA006 |  6 |  7 | AAA006
+ 66 |  6 | 00066 | Sun Mar 08 00:00:00 1970 PST | Sun Mar 08 00:00:00 1970 | 6  | 6          | foo | 66 |  6 | 00066 | Sun Mar 08 00:00:00 1970 PST | Sun Mar 08 00:00:00 1970 | 6  | 6          | foo |  6 |  7 | AAA006 |  6 |  7 | AAA006
+ 76 |  6 | 00076 | Wed Mar 18 00:00:00 1970 PST | Wed Mar 18 00:00:00 1970 | 6  | 6          | foo | 76 |  6 | 00076 | Wed Mar 18 00:00:00 1970 PST | Wed Mar 18 00:00:00 1970 | 6  | 6          | foo |  6 |  7 | AAA006 |  6 |  7 | AAA006
+ 86 |  6 | 00086 | Sat Mar 28 00:00:00 1970 PST | Sat Mar 28 00:00:00 1970 | 6  | 6          | foo | 86 |  6 | 00086 | Sat Mar 28 00:00:00 1970 PST | Sat Mar 28 00:00:00 1970 | 6  | 6          | foo |  6 |  7 | AAA006 |  6 |  7 | AAA006
+ 96 |  6 | 00096 | Tue Apr 07 00:00:00 1970 PST | Tue Apr 07 00:00:00 1970 | 6  | 6          | foo | 96 |  6 | 00096 | Tue Apr 07 00:00:00 1970 PST | Tue Apr 07 00:00:00 1970 | 6  | 6          | foo |  6 |  7 | AAA006 |  6 |  7 | AAA006
+(10 rows)
 
+RESET enable_nestloop;
+RESET enable_hashjoin;
 -- check join pushdown in situations where multiple userids are involved
 CREATE ROLE regress_view_owner SUPERUSER;
 CREATE USER MAPPING FOR regress_view_owner SERVER loopback;

contrib/postgres_fdw/sql/postgres_fdw.sql

@@ -560,11 +560,16 @@ SELECT ft5, ft5.c1, ft5.c2, ft5.c3, ft4.c1, ft4.c2 FROM ft5 left join ft4 on ft5
 SELECT ft5, ft5.c1, ft5.c2, ft5.c3, ft4.c1, ft4.c2 FROM ft5 left join ft4 on ft5.c1 = ft4.c1 WHERE ft4.c1 BETWEEN 10 and 30 ORDER BY ft5.c1, ft4.c1;
 
 -- multi-way join involving multiple merge joins
+-- (this case used to have EPQ-related planning problems)
+SET enable_nestloop TO false;
+SET enable_hashjoin TO false;
 EXPLAIN (VERBOSE, COSTS OFF)
-SELECT * FROM ft1, ft2, ft4, ft5 WHERE ft1.c1 = ft2.c1 AND ft1.c1 = ft4.c1
-    AND ft1.c1 = ft5.c1 FOR UPDATE;
-SELECT * FROM ft1, ft2, ft4, ft5 WHERE ft1.c1 = ft2.c1 AND ft1.c1 = ft4.c1
-    AND ft1.c1 = ft5.c1 FOR UPDATE;
+SELECT * FROM ft1, ft2, ft4, ft5 WHERE ft1.c1 = ft2.c1 AND ft1.c2 = ft4.c1
+    AND ft1.c2 = ft5.c1 AND ft1.c1 < 100 AND ft2.c1 < 100 FOR UPDATE;
+SELECT * FROM ft1, ft2, ft4, ft5 WHERE ft1.c1 = ft2.c1 AND ft1.c2 = ft4.c1
+    AND ft1.c2 = ft5.c1 AND ft1.c1 < 100 AND ft2.c1 < 100 FOR UPDATE;
+RESET enable_nestloop;
+RESET enable_hashjoin;
 
 -- check join pushdown in situations where multiple userids are involved
 CREATE ROLE regress_view_owner SUPERUSER;