PG17 compatibility: fix diff in tableam (#7771)

Test `tableam` expects that this CREATE TABLE statement: `CREATE TABLE
test_partitioned(id int, p int, val int) PARTITION BY RANGE (p) USING
fake_am;`
will produce this error:
`specifying a table access method is not supported on a partitioned
table`

but as of [this PG
commit](https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=374c7a229)
it is possible to specify an access method on a partitioned table. This
fix moves the CREATE TABLE statement to pg17, and adds an additional
test to show parent access method is inherited.

src/test/regress/expected/pg17.out

@@ -352,3 +352,74 @@ drop cascades to table pg17_corr_subq_folding.events
 \endif
 -- PG17-specific tests go here.
 --
+CREATE SCHEMA pg17;
+SET search_path TO pg17;
+-- Test specifying access method on partitioned tables. PG17 feature, added by:
+-- https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=374c7a229
+-- The following tests were failing tests in tableam but will pass on PG >= 17.
+-- There is some set-up duplication of tableam, and this test can be returned
+-- to tableam when 17 is the minimum supported PG version.
+SELECT public.run_command_on_coordinator_and_workers($Q$
+	SET citus.enable_ddl_propagation TO off;
+	CREATE FUNCTION fake_am_handler(internal)
+	RETURNS table_am_handler
+	AS 'citus'
+	LANGUAGE C;
+	CREATE ACCESS METHOD fake_am TYPE TABLE HANDLER fake_am_handler;
+$Q$);
+ run_command_on_coordinator_and_workers
+---------------------------------------------------------------------
+
+(1 row)
+
+-- Since Citus assumes access methods are part of the extension, make fake_am
+-- owned manually to be able to pass checks on Citus while distributing tables.
+ALTER EXTENSION citus ADD ACCESS METHOD fake_am;
+CREATE TABLE test_partitioned(id int, p int, val int)
+PARTITION BY RANGE (p) USING fake_am;
+-- Test that children inherit access method from parent
+CREATE TABLE test_partitioned_p1 PARTITION OF test_partitioned
+	FOR VALUES FROM (1) TO (10);
+CREATE TABLE test_partitioned_p2 PARTITION OF test_partitioned
+	FOR VALUES FROM (11) TO (20);
+INSERT INTO test_partitioned VALUES (1, 5, -1), (2, 15, -2);
+WARNING:  fake_tuple_insert
+WARNING:  fake_tuple_insert
+INSERT INTO test_partitioned VALUES (3, 6, -6), (4, 16, -4);
+WARNING:  fake_tuple_insert
+WARNING:  fake_tuple_insert
+SELECT count(1) FROM test_partitioned_p1;
+WARNING:  fake_scan_getnextslot
+WARNING:  fake_scan_getnextslot
+WARNING:  fake_scan_getnextslot
+ count
+---------------------------------------------------------------------
+     2
+(1 row)
+
+SELECT count(1) FROM test_partitioned_p2;
+WARNING:  fake_scan_getnextslot
+WARNING:  fake_scan_getnextslot
+WARNING:  fake_scan_getnextslot
+ count
+---------------------------------------------------------------------
+     2
+(1 row)
+
+-- Both child table partitions inherit fake_am
+SELECT c.relname, am.amname FROM pg_class c, pg_am am
+WHERE c.relam = am.oid AND c.oid IN ('test_partitioned_p1'::regclass, 'test_partitioned_p2'::regclass)
+ORDER BY c.relname;
+       relname       | amname
+---------------------------------------------------------------------
+ test_partitioned_p1 | fake_am
+ test_partitioned_p2 | fake_am
+(2 rows)
+
+DROP TABLE test_partitioned;
+ALTER EXTENSION citus DROP ACCESS METHOD fake_am;
+-- End of testing specifying access method on partitioned tables.
+DROP SCHEMA pg17 CASCADE;
+NOTICE:  drop cascades to 2 other objects
+DETAIL:  drop cascades to function fake_am_handler(internal)
+drop cascades to access method fake_am

src/test/regress/expected/tableam.out

@@ -281,12 +281,6 @@ DETAIL:  from localhost:xxxxx
 (1 row)
 
 DROP TABLE test_partitioned;
--- Specifying access method in parent is not supported.
--- If the below statement ever succeeds, add more tests for
--- the case where children inherit access method from parent.
-CREATE TABLE test_partitioned(id int, p int, val int)
-PARTITION BY RANGE (p) USING fake_am;
-ERROR:  specifying a table access method is not supported on a partitioned table
 \set VERBOSITY terse
 ALTER EXTENSION citus DROP ACCESS METHOD fake_am;
 NOTICE:  Citus does not propagate adding/dropping member objects

src/test/regress/sql/pg17.sql

@@ -180,3 +180,51 @@ DROP SCHEMA pg17_corr_subq_folding CASCADE;
 
 -- PG17-specific tests go here.
 --
+CREATE SCHEMA pg17;
+SET search_path TO pg17;
+
+-- Test specifying access method on partitioned tables. PG17 feature, added by:
+-- https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=374c7a229
+-- The following tests were failing tests in tableam but will pass on PG >= 17.
+-- There is some set-up duplication of tableam, and this test can be returned
+-- to tableam when 17 is the minimum supported PG version.
+
+SELECT public.run_command_on_coordinator_and_workers($Q$
+	SET citus.enable_ddl_propagation TO off;
+	CREATE FUNCTION fake_am_handler(internal)
+	RETURNS table_am_handler
+	AS 'citus'
+	LANGUAGE C;
+	CREATE ACCESS METHOD fake_am TYPE TABLE HANDLER fake_am_handler;
+$Q$);
+
+-- Since Citus assumes access methods are part of the extension, make fake_am
+-- owned manually to be able to pass checks on Citus while distributing tables.
+ALTER EXTENSION citus ADD ACCESS METHOD fake_am;
+
+CREATE TABLE test_partitioned(id int, p int, val int)
+PARTITION BY RANGE (p) USING fake_am;
+
+-- Test that children inherit access method from parent
+CREATE TABLE test_partitioned_p1 PARTITION OF test_partitioned
+	FOR VALUES FROM (1) TO (10);
+CREATE TABLE test_partitioned_p2 PARTITION OF test_partitioned
+	FOR VALUES FROM (11) TO (20);
+
+INSERT INTO test_partitioned VALUES (1, 5, -1), (2, 15, -2);
+INSERT INTO test_partitioned VALUES (3, 6, -6), (4, 16, -4);
+
+SELECT count(1) FROM test_partitioned_p1;
+SELECT count(1) FROM test_partitioned_p2;
+
+-- Both child table partitions inherit fake_am
+SELECT c.relname, am.amname FROM pg_class c, pg_am am
+WHERE c.relam = am.oid AND c.oid IN ('test_partitioned_p1'::regclass, 'test_partitioned_p2'::regclass)
+ORDER BY c.relname;
+
+DROP TABLE test_partitioned;
+ALTER EXTENSION citus DROP ACCESS METHOD fake_am;
+
+-- End of testing specifying access method on partitioned tables.
+
+DROP SCHEMA pg17 CASCADE;

src/test/regress/sql/tableam.sql

@@ -138,12 +138,6 @@ SELECT count(*) FROM test_partitioned;
 
 DROP TABLE test_partitioned;
 
--- Specifying access method in parent is not supported.
--- If the below statement ever succeeds, add more tests for
--- the case where children inherit access method from parent.
-CREATE TABLE test_partitioned(id int, p int, val int)
-PARTITION BY RANGE (p) USING fake_am;
-
 \set VERBOSITY terse
 ALTER EXTENSION citus DROP ACCESS METHOD fake_am;
 drop schema test_tableam cascade;