\set VERBOSITY terse
SET search_path = 'public';
CREATE EXTENSION pg_pathman;
CREATE SCHEMA multi;
/* Check that multilevel is prohibited */
CREATE TABLE multi.test(key int NOT NULL);
SELECT create_hash_partitions('multi.test', 'key', 3);
 create_hash_partitions 
------------------------
                      3
(1 row)

SELECT create_hash_partitions('multi.test_1', 'key', 3);
ERROR:  multilevel partitioning is not supported
DROP TABLE multi.test CASCADE;
NOTICE:  drop cascades to 3 other objects
/* Attach partitioned subtree to 'abc' */
CREATE TABLE multi.abc (val int NOT NULL);
CREATE TABLE multi.def (LIKE multi.abc);
SELECT create_hash_partitions('multi.def', 'val', 2);
 create_hash_partitions 
------------------------
                      2
(1 row)

ALTER TABLE multi.def INHERIT multi.abc;
/*
 * Although multilevel partitioning is not supported,
 * we must make sure that pg_pathman won't add
 * duplicate relations to the final plan.
 */
EXPLAIN (COSTS OFF) TABLE multi.abc;
       QUERY PLAN        
-------------------------
 Append
   ->  Seq Scan on abc
   ->  Seq Scan on def
   ->  Seq Scan on def_0
   ->  Seq Scan on def_1
(5 rows)

DROP SCHEMA multi CASCADE;
NOTICE:  drop cascades to 4 other objects
DROP EXTENSION pg_pathman;