Add a test case for a316a3bc

a316a3bc fixed the code in build_simpl_rel() that propagates
RelOptInfo.userid from parent to child rels so that it works
correctly for the child rels of a UNION ALL subquery rel, though
no tests were added in that commit.  So do so here.

As noted in the discussion, coming up with a test case in the core
regression suite for this fix has turned out to be tricky, so the
test case is added to the postgres_fdw's suite instead.
postgresGetForeignRelSize()'s use of user mapping for the user
specified in RelOptInfo.userid makes it relatively easier to craft
a test case around.

Discussion: https://postgr.es/m/CA%2BHiwqH91GaFNXcXbLAM9L%3DzBwUmSyv699Mtv3i1_xtk9Xec_A%40mail.gmail.com
Backpatch-through: 16
This commit is contained in:
Amit Langote 2023-06-30 15:48:54 +09:00
parent f4691e2e76
commit 0a14bca662
2 changed files with 65 additions and 0 deletions

View File

@ -2689,6 +2689,48 @@ SELECT t1.c1, t2.c2 FROM v4 t1 LEFT JOIN ft5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c
(10 rows)
ALTER VIEW v4 OWNER TO regress_view_owner;
-- ====================================================================
-- Check that userid to use when querying the remote table is correctly
-- propagated into foreign rels present in subqueries under an UNION ALL
-- ====================================================================
CREATE ROLE regress_view_owner_another;
ALTER VIEW v4 OWNER TO regress_view_owner_another;
GRANT SELECT ON ft4 TO regress_view_owner_another;
ALTER FOREIGN TABLE ft4 OPTIONS (ADD use_remote_estimate 'true');
-- The following should query the remote backing table of ft4 as user
-- regress_view_owner_another, the view owner, though it fails as expected
-- due to the lack of a user mapping for that user.
EXPLAIN (VERBOSE, COSTS OFF) SELECT * FROM v4;
ERROR: user mapping not found for "regress_view_owner_another"
-- Likewise, but with the query under an UNION ALL
EXPLAIN (VERBOSE, COSTS OFF) SELECT * FROM (SELECT * FROM v4 UNION ALL SELECT * FROM v4);
ERROR: user mapping not found for "regress_view_owner_another"
-- Should not get that error once a user mapping is created
CREATE USER MAPPING FOR regress_view_owner_another SERVER loopback OPTIONS (password_required 'false');
EXPLAIN (VERBOSE, COSTS OFF) SELECT * FROM v4;
QUERY PLAN
--------------------------------------------------
Foreign Scan on public.ft4
Output: ft4.c1, ft4.c2, ft4.c3
Remote SQL: SELECT c1, c2, c3 FROM "S 1"."T 3"
(3 rows)
EXPLAIN (VERBOSE, COSTS OFF) SELECT * FROM (SELECT * FROM v4 UNION ALL SELECT * FROM v4);
QUERY PLAN
--------------------------------------------------------
Append
-> Foreign Scan on public.ft4
Output: ft4.c1, ft4.c2, ft4.c3
Remote SQL: SELECT c1, c2, c3 FROM "S 1"."T 3"
-> Foreign Scan on public.ft4 ft4_1
Output: ft4_1.c1, ft4_1.c2, ft4_1.c3
Remote SQL: SELECT c1, c2, c3 FROM "S 1"."T 3"
(7 rows)
DROP USER MAPPING FOR regress_view_owner_another SERVER loopback;
DROP OWNED BY regress_view_owner_another;
DROP ROLE regress_view_owner_another;
ALTER FOREIGN TABLE ft4 OPTIONS (SET use_remote_estimate 'false');
-- cleanup
DROP OWNED BY regress_view_owner;
DROP ROLE regress_view_owner;

View File

@ -714,6 +714,29 @@ SELECT t1.c1, t2.c2 FROM v4 t1 LEFT JOIN ft5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c
SELECT t1.c1, t2.c2 FROM v4 t1 LEFT JOIN ft5 t2 ON (t1.c1 = t2.c1) ORDER BY t1.c1, t2.c1 OFFSET 10 LIMIT 10;
ALTER VIEW v4 OWNER TO regress_view_owner;
-- ====================================================================
-- Check that userid to use when querying the remote table is correctly
-- propagated into foreign rels present in subqueries under an UNION ALL
-- ====================================================================
CREATE ROLE regress_view_owner_another;
ALTER VIEW v4 OWNER TO regress_view_owner_another;
GRANT SELECT ON ft4 TO regress_view_owner_another;
ALTER FOREIGN TABLE ft4 OPTIONS (ADD use_remote_estimate 'true');
-- The following should query the remote backing table of ft4 as user
-- regress_view_owner_another, the view owner, though it fails as expected
-- due to the lack of a user mapping for that user.
EXPLAIN (VERBOSE, COSTS OFF) SELECT * FROM v4;
-- Likewise, but with the query under an UNION ALL
EXPLAIN (VERBOSE, COSTS OFF) SELECT * FROM (SELECT * FROM v4 UNION ALL SELECT * FROM v4);
-- Should not get that error once a user mapping is created
CREATE USER MAPPING FOR regress_view_owner_another SERVER loopback OPTIONS (password_required 'false');
EXPLAIN (VERBOSE, COSTS OFF) SELECT * FROM v4;
EXPLAIN (VERBOSE, COSTS OFF) SELECT * FROM (SELECT * FROM v4 UNION ALL SELECT * FROM v4);
DROP USER MAPPING FOR regress_view_owner_another SERVER loopback;
DROP OWNED BY regress_view_owner_another;
DROP ROLE regress_view_owner_another;
ALTER FOREIGN TABLE ft4 OPTIONS (SET use_remote_estimate 'false');
-- cleanup
DROP OWNED BY regress_view_owner;
DROP ROLE regress_view_owner;