\set VERBOSITY terse
SET citus.next_shard_id TO 1518000;
SET citus.shard_replication_factor TO 1;
CREATE SCHEMA fkeys_between_local_ref;
SET search_path TO fkeys_between_local_ref;
SET client_min_messages to ERROR;
-- create a view for testing
CREATE VIEW citus_local_tables_in_schema AS
SELECT logicalrelid FROM pg_dist_partition, pg_tables
WHERE tablename=logicalrelid::regclass::text AND
      schemaname='fkeys_between_local_ref' AND
      partmethod = 'n' AND repmodel = 'c';
-- remove coordinator if it is added to pg_dist_node and test
-- behavior when coordinator is not added to metadata
SELECT COUNT(master_remove_node(nodename, nodeport)) < 2
FROM pg_dist_node WHERE nodename='localhost' AND nodeport=:master_port;
 ?column?
---------------------------------------------------------------------
 t
(1 row)

create table ref (a int primary key);
select create_reference_table('ref');
 create_reference_table
---------------------------------------------------------------------

(1 row)

-- creating local table that references to reference table is supported
create table other (x int primary key, y int);
-- creating reference table from a local table that references
-- to reference table is supported
alter table other add constraint fk foreign key (y) references ref (a) on delete cascade;
select create_reference_table('other');
 create_reference_table
---------------------------------------------------------------------

(1 row)

drop table if exists ref, ref2 cascade;
create table ref (a int primary key);
create table ref2 (x int);
alter table ref2 add constraint fk foreign key (x) references ref (a);
select create_reference_table('ref');
 create_reference_table
---------------------------------------------------------------------

(1 row)

-- we can also define more foreign keys after creating reference
-- table from referenced table
alter table ref2 add constraint fk2 foreign key (x) references ref (a);
-- then we can create reference table from referencing table
select create_reference_table('ref2');
 create_reference_table
---------------------------------------------------------------------

(1 row)

drop table if exists ref, ref2, other cascade;
-- add coordinator to pg_dist_node for rest of the tests
SELECT 1 FROM master_add_node('localhost', :master_port, groupId => 0);
 ?column?
---------------------------------------------------------------------
        1
(1 row)

CREATE TABLE local_table_1 (col_1 INT UNIQUE);
CREATE TABLE local_table_2 (col_1 INT UNIQUE);
CREATE TABLE local_table_3 (col_1 INT UNIQUE);
CREATE TABLE local_table_4 (col_1 INT UNIQUE);
INSERT INTO local_table_1 SELECT i FROM generate_series(195, 205) i;
INSERT INTO local_table_2 SELECT i FROM generate_series(195, 205) i;
INSERT INTO local_table_3 SELECT i FROM generate_series(195, 205) i;
INSERT INTO local_table_4 SELECT i FROM generate_series(195, 205) i;
--                                        _
--                                       | |
--                                       | v
-- local_table_2 -> local_table_1 -> local_table_4
--                      ^ |               |
--                      | v               |
--                  local_table_3 <--------
ALTER TABLE local_table_2 ADD CONSTRAINT fkey_1 FOREIGN KEY (col_1) REFERENCES local_table_1(col_1);
ALTER TABLE local_table_3 ADD CONSTRAINT fkey_2 FOREIGN KEY (col_1) REFERENCES local_table_1(col_1);
ALTER TABLE local_table_1 ADD CONSTRAINT fkey_3 FOREIGN KEY (col_1) REFERENCES local_table_3(col_1);
ALTER TABLE local_table_1 ADD CONSTRAINT fkey_4 FOREIGN KEY (col_1) REFERENCES local_table_4(col_1);
ALTER TABLE local_table_4 ADD CONSTRAINT fkey_5 FOREIGN KEY (col_1) REFERENCES local_table_3(col_1);
ALTER TABLE local_table_4 ADD CONSTRAINT fkey_6 FOREIGN KEY (col_1) REFERENCES local_table_4(col_1);
CREATE TABLE reference_table_1(col_1 INT UNIQUE, col_2 INT);
INSERT INTO reference_table_1 SELECT i FROM generate_series(195, 205) i;
SELECT create_reference_table('reference_table_1');
 create_reference_table
---------------------------------------------------------------------

(1 row)

CREATE TABLE partitioned_table_1 (col_1 INT, col_2 INT) PARTITION BY RANGE (col_1);
CREATE TABLE partitioned_table_1_100_200 PARTITION OF partitioned_table_1 FOR VALUES FROM (100) TO (200);
CREATE TABLE partitioned_table_1_200_300 PARTITION OF partitioned_table_1 FOR VALUES FROM (200) TO (300);
INSERT INTO partitioned_table_1 SELECT i FROM generate_series(195, 205) i;
ALTER TABLE partitioned_table_1 ADD CONSTRAINT fkey_8 FOREIGN KEY (col_1) REFERENCES local_table_4(col_1);
-- now that we attached partitioned table to graph below errors out
-- since we cannot create citus local table from partitioned tables
ALTER TABLE reference_table_1 ADD CONSTRAINT fkey_9 FOREIGN KEY (col_1) REFERENCES local_table_1(col_1);
ERROR:  cannot create citus local table "partitioned_table_1", only regular tables and foreign tables are supported for citus local table creation
ALTER TABLE partitioned_table_1 DROP CONSTRAINT fkey_8;
BEGIN;
  -- now that we detached partitioned table from graph, succeeds
  ALTER TABLE reference_table_1 ADD CONSTRAINT fkey_10 FOREIGN KEY (col_1) REFERENCES local_table_1(col_1);
  -- show that we converted all 4 local tables in this schema to citus local tables
  SELECT COUNT(*)=4 FROM citus_local_tables_in_schema;
 ?column?
---------------------------------------------------------------------
 t
(1 row)

ROLLBACK;
-- this actually attempts to convert local tables to citus local tables but errors out
-- as citus doesn't support defining foreign keys via add column commands
ALTER TABLE local_table_1 ADD COLUMN col_3 INT REFERENCES reference_table_1(col_1);
ERROR:  cannot execute ADD COLUMN command with PRIMARY KEY, UNIQUE, FOREIGN and CHECK constraints
BEGIN;
  -- define a foreign key so that all 4 local tables become citus local tables
  ALTER TABLE local_table_1 ADD CONSTRAINT fkey_11 FOREIGN KEY (col_1) REFERENCES reference_table_1(col_1);
  CREATE TABLE local_table_5 (col_1 INT UNIQUE);
  -- now define foreign key from local to citus local table
  ALTER TABLE local_table_5 ADD CONSTRAINT fkey_12 FOREIGN KEY (col_1) REFERENCES local_table_2(col_1);
  -- now we have 5 citus local tables in this schema
  SELECT COUNT(*)=5 FROM citus_local_tables_in_schema;
 ?column?
---------------------------------------------------------------------
 t
(1 row)

ROLLBACK;
-- they fail as local_table_99 does not exist
ALTER TABLE local_table_99 ADD CONSTRAINT fkey FOREIGN KEY (col_1) REFERENCES reference_table_1(col_1);
ERROR:  relation "local_table_99" does not exist
ALTER TABLE local_table_1 ADD CONSTRAINT fkey FOREIGN KEY (col_1) REFERENCES local_table_99(col_1);
ERROR:  relation "local_table_99" does not exist
-- they fail as col_99 does not exist
ALTER TABLE local_table_1 ADD CONSTRAINT fkey FOREIGN KEY (col_99) REFERENCES reference_table_1(col_1);
ERROR:  column "col_99" referenced in foreign key constraint does not exist
ALTER TABLE local_table_1 ADD CONSTRAINT fkey FOREIGN KEY (col_1) REFERENCES reference_table_1(col_99);
ERROR:  column "col_99" referenced in foreign key constraint does not exist
-- fails as col_2 does not have a unique/primary key constraint
ALTER TABLE local_table_1 ADD CONSTRAINT fkey FOREIGN KEY (col_1) REFERENCES reference_table_1(col_2);
ERROR:  there is no unique constraint matching given keys for referenced table "reference_table_1"
CREATE TABLE reference_table_2 (col_1 INT UNIQUE, col_2 INT);
INSERT INTO reference_table_2 SELECT i FROM generate_series(195, 205) i;
BEGIN;
  -- define foreign key when both ends are local tables
  ALTER TABLE local_table_1 ADD CONSTRAINT fkey_11 FOREIGN KEY (col_1) REFERENCES reference_table_2(col_1);
  -- we still don't convert local tables to citus local tables when
  -- creating reference tables
  SELECT create_reference_table('reference_table_2');
 create_reference_table
---------------------------------------------------------------------

(1 row)

  -- now defining another foreign key would convert local tables to
  -- citus local tables as reference_table_2 is now a reference table
  ALTER TABLE local_table_1 ADD CONSTRAINT fkey_12 FOREIGN KEY (col_1) REFERENCES reference_table_2(col_1);
  -- now print metadata to show that everyting is fine
  SELECT logicalrelid::text AS tablename, partmethod, repmodel FROM pg_dist_partition
  WHERE logicalrelid::text IN (SELECT tablename FROM pg_tables WHERE schemaname='fkeys_between_local_ref')
  ORDER BY tablename;
     tablename     | partmethod | repmodel
---------------------------------------------------------------------
 local_table_1     | n          | c
 local_table_2     | n          | c
 local_table_3     | n          | c
 local_table_4     | n          | c
 reference_table_1 | n          | t
 reference_table_2 | n          | t
(6 rows)

ROLLBACK;
-- we don't support foreign keys from citus local to reference tables
-- with ON DELETE/UPDATE CASCADE behavior, so below two errors out
BEGIN;
  SELECT create_reference_table('reference_table_2');
 create_reference_table
---------------------------------------------------------------------

(1 row)

  ALTER TABLE reference_table_2 ADD CONSTRAINT fkey_11 FOREIGN KEY (col_1) REFERENCES local_table_2(col_1) ON DELETE CASCADE;
ERROR:  cannot define foreign key constraint, foreign keys from reference tables to citus local tables can only be defined with NO ACTION or RESTRICT behaviors
ROLLBACK;
BEGIN;
  SELECT create_reference_table('reference_table_2');
 create_reference_table
---------------------------------------------------------------------

(1 row)

  ALTER TABLE reference_table_2 ADD CONSTRAINT fkey_local_to_ref FOREIGN KEY (col_1) REFERENCES local_table_2(col_1) ON UPDATE CASCADE;
ERROR:  cannot define foreign key constraint, foreign keys from reference tables to citus local tables can only be defined with NO ACTION or RESTRICT behaviors
ROLLBACK;
-- but we support such foreign key behaviors when foreign key is from
-- citus local to reference table
BEGIN;
  SELECT create_reference_table('reference_table_2');
 create_reference_table
---------------------------------------------------------------------

(1 row)

  ALTER TABLE local_table_2 ADD CONSTRAINT fkey_11 FOREIGN KEY (col_1) REFERENCES reference_table_2(col_1) ON DELETE CASCADE;
  DELETE FROM reference_table_2 WHERE col_1=200;
  -- we deleted one row as DELETE cascades, so we should have 10 rows
  SELECT COUNT(*) FROM local_table_2;
 count
---------------------------------------------------------------------
    10
(1 row)

ROLLBACK;
BEGIN;
  SELECT create_reference_table('reference_table_2');
 create_reference_table
---------------------------------------------------------------------

(1 row)

  ALTER TABLE local_table_2 ADD CONSTRAINT fkey_11 FOREIGN KEY (col_1) REFERENCES reference_table_2(col_1) ON UPDATE CASCADE;
ROLLBACK;
-- cleanup at exit
DROP SCHEMA fkeys_between_local_ref CASCADE;