-- -- PG17 -- SHOW server_version \gset SELECT substring(:'server_version', '\d+')::int >= 17 AS server_version_ge_17 \gset -- PG17 has the capabilty to pull up a correlated ANY subquery to a join if -- the subquery only refers to its immediate parent query. Previously, the -- subquery needed to be implemented as a SubPlan node, typically as a -- filter on a scan or join node. This PG17 capability enables Citus to -- run queries with correlated subqueries in certain cases, as shown here. -- Relevant PG commit: -- https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=9f1337639 -- This feature is tested for all PG versions, not just PG17; each test query with -- a correlated subquery should fail with PG version < 17.0, but the test query -- rewritten to reflect how PG17 optimizes it should succeed with PG < 17.0 CREATE SCHEMA pg17_corr_subq_folding; SET search_path TO pg17_corr_subq_folding; SET citus.next_shard_id TO 20240017; SET citus.shard_count TO 2; SET citus.shard_replication_factor TO 1; CREATE TABLE test (x int, y int); SELECT create_distributed_table('test', 'x'); INSERT INTO test VALUES (1,1), (2,2); -- Query 1: WHERE clause has a correlated subquery with a UNION. PG17 can plan -- this as a nested loop join with the subquery as the inner. The correlation -- is on the distribution column so the join can be pushed down by Citus. explain (costs off) SELECT * FROM test a WHERE x IN (SELECT x FROM test b UNION SELECT y FROM test c WHERE a.x = c.x) ORDER BY 1,2; SET client_min_messages TO DEBUG2; SELECT * FROM test a WHERE x IN (SELECT x FROM test b UNION SELECT y FROM test c WHERE a.x = c.x) ORDER BY 1,2; RESET client_min_messages; -- Query 1 rewritten with subquery pulled up to a join, as done by PG17 planner; -- this query can be run without issues by Citus with older (pre PG17) PGs. explain (costs off) SELECT a.* FROM test a JOIN LATERAL (SELECT x FROM test b UNION SELECT y FROM test c WHERE a.x = c.x) dt1 ON a.x = dt1.x ORDER BY 1,2; SET client_min_messages TO DEBUG2; SELECT a.* FROM test a JOIN LATERAL (SELECT x FROM test b UNION SELECT y FROM test c WHERE a.x = c.x) dt1 ON a.x = dt1.x ORDER BY 1,2; RESET client_min_messages; CREATE TABLE users (user_id int, time int, dept int, info bigint); CREATE TABLE events (user_id int, time int, event_type int, payload text); select create_distributed_table('users', 'user_id'); select create_distributed_table('events', 'user_id'); insert into users select i, 2021 + (i % 3), i % 5, 99999 * i from generate_series(1, 10) i; insert into events select i % 10 + 1, 2021 + (i % 3), i %11, md5((i*i)::text) from generate_series(1, 100) i; -- Query 2. In Citus correlated subqueries can not be used in the WHERE -- clause but if the subquery can be pulled up to a join it becomes possible -- for Citus to run the query, per this example. Pre PG17 the suqbuery -- was implemented as a SubPlan filter on the events table scan. EXPLAIN (costs off) WITH event_id AS(SELECT user_id AS events_user_id, time AS events_time, event_type FROM events) SELECT Count(*) FROM event_id WHERE (events_user_id) IN (SELECT user_id FROM users WHERE users.time = events_time); SET client_min_messages TO DEBUG2; WITH event_id AS(SELECT user_id AS events_user_id, time AS events_time, event_type FROM events) SELECT Count(*) FROM event_id WHERE (events_user_id) IN (SELECT user_id FROM users WHERE users.time = events_time); RESET client_min_messages; -- Query 2 rewritten with subquery pulled up to a join, as done by pg17 planner. Citus -- Citus is able to run this query with previous pg versions. Note that the CTE can be -- disregarded because it is inlined, being only referenced once. EXPLAIN (COSTS OFF) SELECT Count(*) FROM (SELECT user_id AS events_user_id, time AS events_time, event_type FROM events) dt1 INNER JOIN (SELECT distinct user_id, time FROM users) dt ON events_user_id = dt.user_id and events_time = dt.time; SET client_min_messages TO DEBUG2; SELECT Count(*) FROM (SELECT user_id AS events_user_id, time AS events_time, event_type FROM events) dt1 INNER JOIN (SELECT distinct user_id, time FROM users) dt ON events_user_id = dt.user_id and events_time = dt.time; RESET client_min_messages; -- Query 3: another example where recursive planning was prevented due to -- correlated subqueries, but with PG17 folding the subquery to a join it is -- possible for Citus to plan and run the query. EXPLAIN (costs off) SELECT dept, sum(user_id) FROM (SELECT users.dept, users.user_id FROM users, events as d1 WHERE d1.user_id = users.user_id AND users.dept IN (3,4) AND users.user_id IN (SELECT s2.user_id FROM users as s2 GROUP BY d1.user_id, s2.user_id)) dt GROUP BY dept; SET client_min_messages TO DEBUG2; SELECT dept, sum(user_id) FROM (SELECT users.dept, users.user_id FROM users, events as d1 WHERE d1.user_id = users.user_id AND users.dept IN (3,4) AND users.user_id IN (SELECT s2.user_id FROM users as s2 GROUP BY d1.user_id, s2.user_id)) dt GROUP BY dept; RESET client_min_messages; -- Query 3 rewritten in a similar way to how the PG17 pulls up the subquery; -- the join is on the distribution key so Citus can push down. EXPLAIN (costs off) SELECT dept, sum(user_id) FROM (SELECT users.dept, users.user_id FROM users, events as d1 JOIN LATERAL (SELECT s2.user_id FROM users as s2 GROUP BY s2.user_id HAVING d1.user_id IS NOT NULL) as d2 ON 1=1 WHERE d1.user_id = users.user_id AND users.dept IN (3,4) AND users.user_id = d2.user_id) dt GROUP BY dept; SET client_min_messages TO DEBUG2; SELECT dept, sum(user_id) FROM (SELECT users.dept, users.user_id FROM users, events as d1 JOIN LATERAL (SELECT s2.user_id FROM users as s2 GROUP BY s2.user_id HAVING d1.user_id IS NOT NULL) as d2 ON 1=1 WHERE d1.user_id = users.user_id AND users.dept IN (3,4) AND users.user_id = d2.user_id) dt GROUP BY dept; RESET client_min_messages; RESET search_path; DROP SCHEMA pg17_corr_subq_folding CASCADE; \if :server_version_ge_17 \else \q \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; $Q$); -- 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; -- Clean up DROP TABLE test_partitioned; ALTER EXTENSION citus DROP ACCESS METHOD fake_am; SELECT public.run_command_on_coordinator_and_workers($Q$ RESET citus.enable_ddl_propagation; $Q$); -- End of testing specifying access method on partitioned tables. -- MAINTAIN privilege tests CREATE ROLE regress_maintain; CREATE ROLE regress_no_maintain; ALTER ROLE regress_maintain WITH login; GRANT USAGE ON SCHEMA pg17 TO regress_maintain; ALTER ROLE regress_no_maintain WITH login; GRANT USAGE ON SCHEMA pg17 TO regress_no_maintain; SET citus.shard_count TO 1; -- For consistent remote command logging CREATE TABLE dist_test(a int, b int); SELECT create_distributed_table('dist_test', 'a'); INSERT INTO dist_test SELECT i % 10, i FROM generate_series(1, 100) t(i); SET citus.log_remote_commands TO on; SET citus.grep_remote_commands = '%maintain%'; GRANT MAINTAIN ON dist_test TO regress_maintain; RESET citus.grep_remote_commands; SET ROLE regress_no_maintain; -- Current role does not have MAINTAIN privileges on dist_test ANALYZE dist_test; VACUUM dist_test; SET ROLE regress_maintain; -- Current role has MAINTAIN privileges on dist_test ANALYZE dist_test; VACUUM dist_test; -- Take away regress_maintain's MAINTAIN privileges on dist_test RESET ROLE; SET citus.grep_remote_commands = '%maintain%'; REVOKE MAINTAIN ON dist_test FROM regress_maintain; RESET citus.grep_remote_commands; SET ROLE regress_maintain; -- Current role does not have MAINTAIN privileges on dist_test ANALYZE dist_test; VACUUM dist_test; RESET ROLE; -- End of MAINTAIN privilege tests -- Partitions inherit identity column RESET citus.log_remote_commands; -- PG17 added support for identity columns in partioned tables: -- https://git.postgresql.org/gitweb/?p=postgresql.git;a=commitdiff;h=699586315 -- In particular, partitions with their own identity columns are not allowed. -- Citus does not need to propagate identity columns in partitions; the identity -- is inherited by PG17 behavior, as shown in this test. CREATE TABLE partitioned_table ( a bigint GENERATED BY DEFAULT AS IDENTITY (START WITH 10 INCREMENT BY 10), c int ) PARTITION BY RANGE (c); CREATE TABLE pt_1 PARTITION OF partitioned_table FOR VALUES FROM (1) TO (50); SELECT create_distributed_table('partitioned_table', 'a'); CREATE TABLE pt_2 PARTITION OF partitioned_table FOR VALUES FROM (50) TO (1000); -- (1) The partitioned table has pt_1 and pt_2 as its partitions \d+ partitioned_table; -- (2) The partitions have the same identity column as the parent table; -- This is PG17 behavior for support for identity in partitioned tables. \d pt_1; \d pt_2; -- Attaching a partition inherits the identity column from the parent table CREATE TABLE pt_3 (a bigint not null, c int); ALTER TABLE partitioned_table ATTACH PARTITION pt_3 FOR VALUES FROM (1000) TO (2000); \d+ partitioned_table; \d pt_3; -- Partition pt_4 has its own identity column, which is not allowed in PG17 -- and will produce an error on attempting to attach it to the partitioned table CREATE TABLE pt_4 (a bigint GENERATED BY DEFAULT AS IDENTITY (START WITH 10 INCREMENT BY 10), c int); ALTER TABLE partitioned_table ATTACH PARTITION pt_4 FOR VALUES FROM (2000) TO (3000); \c - - - :worker_1_port SET search_path TO pg17; -- Show that DDL for partitioned_table has correctly propagated to the worker node; -- (1) The partitioned table has pt_1, pt_2 and pt_3 as its partitions \d+ partitioned_table; -- (2) The partititions have the same identity column as the parent table \d pt_1; \d pt_2; \d pt_3; \c - - - :master_port SET search_path TO pg17; -- Test detaching a partition with an identity column ALTER TABLE partitioned_table DETACH PARTITION pt_3; -- partitioned_table has pt_1, pt_2 as its partitions -- and pt_3 does not have an identity column \d+ partitioned_table; \d pt_3; -- Verify that the detach has propagated to the worker node \c - - - :worker_1_port SET search_path TO pg17; \d+ partitioned_table; \d pt_3; \c - - - :master_port SET search_path TO pg17; CREATE TABLE alt_test (a int, b date, c int) PARTITION BY RANGE(c); SELECT create_distributed_table('alt_test', 'a'); CREATE TABLE alt_test_pt_1 PARTITION OF alt_test FOR VALUES FROM (1) TO (50); CREATE TABLE alt_test_pt_2 PARTITION OF alt_test FOR VALUES FROM (50) TO (100); -- Citus does not support adding an identity column for a distributed table (#6738) -- Attempting to add a column with identity produces an error ALTER TABLE alt_test ADD COLUMN d bigint GENERATED BY DEFAULT AS IDENTITY (START WITH 10 INCREMENT BY 10); -- alter table set identity is currently not supported, so adding identity to -- an existing column generates an error ALTER TABLE alt_test ALTER COLUMN a SET GENERATED BY DEFAULT SET INCREMENT BY 2 SET START WITH 75 RESTART; -- Verify that the identity column was not added, on coordinator and worker nodes \d+ alt_test; \d alt_test_pt_1; \d alt_test_pt_2; \c - - - :worker_1_port SET search_path TO pg17; \d+ alt_test; \d alt_test_pt_1; \d alt_test_pt_2; \c - - - :master_port SET search_path TO pg17; DROP TABLE alt_test; CREATE TABLE alt_test (a bigint GENERATED BY DEFAULT AS IDENTITY (START WITH 10 INCREMENT BY 10), b int, c int) PARTITION BY RANGE(c); SELECT create_distributed_table('alt_test', 'b'); CREATE TABLE alt_test_pt_1 PARTITION OF alt_test FOR VALUES FROM (1) TO (50); CREATE TABLE alt_test_pt_2 PARTITION OF alt_test FOR VALUES FROM (50) TO (100); -- Dropping of the identity property from a column is currently not supported; -- Attempting to drop identity produces an error ALTER TABLE alt_test ALTER COLUMN a DROP IDENTITY; -- Verify that alt_test still has identity on column a \d+ alt_test; \d alt_test_pt_1; \d alt_test_pt_2; \c - - - :worker_1_port SET search_path TO pg17; \d+ alt_test; \d alt_test_pt_1; \d alt_test_pt_2 \c - - - :master_port SET search_path TO pg17; -- Repeat testing of partitions with identity column on a citus local table CREATE TABLE local_partitioned_table ( a bigint GENERATED BY DEFAULT AS IDENTITY (START WITH 10 INCREMENT BY 10), c int ) PARTITION BY RANGE (c); CREATE TABLE lpt_1 PARTITION OF local_partitioned_table FOR VALUES FROM (1) TO (50); SELECT citus_add_local_table_to_metadata('local_partitioned_table'); -- Can create tables as partitions and attach tables as partitions to a citus local table: CREATE TABLE lpt_2 PARTITION OF local_partitioned_table FOR VALUES FROM (50) TO (1000); CREATE TABLE lpt_3 (a bigint not null, c int); ALTER TABLE local_partitioned_table ATTACH PARTITION lpt_3 FOR VALUES FROM (1000) TO (2000); -- The partitions have the same identity column as the parent table, on coordinator and worker nodes \d+ local_partitioned_table; \d lpt_1; \d lpt_2; \d lpt_3; \c - - - :worker_1_port SET search_path TO pg17; \d+ local_partitioned_table; \d lpt_1; \d lpt_2; \d lpt_3; \c - - - :master_port SET search_path TO pg17; -- Test detaching a partition with an identity column from a citus local table ALTER TABLE local_partitioned_table DETACH PARTITION lpt_3; \d+ local_partitioned_table; \d lpt_3; \c - - - :worker_1_port SET search_path TO pg17; \d+ local_partitioned_table; \d lpt_3; \c - - - :master_port SET search_path TO pg17; DROP TABLE partitioned_table; DROP TABLE local_partitioned_table; DROP TABLE lpt_3; DROP TABLE pt_3; DROP TABLE pt_4; DROP TABLE alt_test; -- End of partition with identity columns testing -- Correlated sublinks are now supported as of PostgreSQL 17, resolving issue #4470. -- Enable DEBUG-level logging to capture detailed execution plans -- Create the tables CREATE TABLE postgres_table (key int, value text, value_2 jsonb); CREATE TABLE reference_table (key int, value text, value_2 jsonb); SELECT create_reference_table('reference_table'); CREATE TABLE distributed_table (key int, value text, value_2 jsonb); SELECT create_distributed_table('distributed_table', 'key'); -- Insert test data INSERT INTO postgres_table SELECT i, i::varchar(256), '{}'::jsonb FROM generate_series(1, 10) i; INSERT INTO reference_table SELECT i, i::varchar(256), '{}'::jsonb FROM generate_series(1, 10) i; INSERT INTO distributed_table SELECT i, i::varchar(256), '{}'::jsonb FROM generate_series(1, 10) i; -- Set local table join policy to auto before running the tests SET citus.local_table_join_policy TO 'auto'; SET client_min_messages TO DEBUG1; -- Correlated sublinks are supported in PostgreSQL 17 SELECT COUNT(*) FROM distributed_table d1 JOIN postgres_table USING (key) WHERE d1.key IN (SELECT key FROM distributed_table WHERE d1.key = key AND key = 5); SELECT COUNT(*) FROM distributed_table d1 JOIN postgres_table USING (key) WHERE d1.key IN (SELECT key FROM distributed_table WHERE d1.key = key AND key = 5); SET citus.local_table_join_policy TO 'prefer-distributed'; SELECT COUNT(*) FROM distributed_table d1 JOIN postgres_table USING (key) WHERE d1.key IN (SELECT key FROM distributed_table WHERE d1.key = key AND key = 5); RESET citus.local_table_join_policy; RESET client_min_messages; DROP TABLE reference_table; -- End for Correlated sublinks are now supported as of PostgreSQL 17, resolving issue #4470. DROP SCHEMA pg17 CASCADE; DROP ROLE regress_maintain; DROP ROLE regress_no_maintain;