\c - - - :master_port
CREATE TABLE the_table (a int, b int, z bigserial);
SELECT create_distributed_table('the_table', 'a');
 create_distributed_table
---------------------------------------------------------------------

(1 row)

CREATE TABLE local (a int, b int);
\c - - - :follower_master_port
-- inserts normally do not work on a standby coordinator
INSERT INTO the_table (a, b, z) VALUES (1, 2, 2);
ERROR:  writing to worker nodes is not currently allowed
DETAIL:  the database is read-only
-- we can allow DML on a writable standby coordinator
SET citus.writable_standby_coordinator TO on;
INSERT INTO the_table (a, b, z) VALUES (1, 2, 2);
SELECT * FROM the_table;
 a | b | z
---------------------------------------------------------------------
 1 | 2 | 2
(1 row)

UPDATE the_table SET z = 3 WHERE a = 1;
SELECT * FROM the_table;
 a | b | z
---------------------------------------------------------------------
 1 | 2 | 3
(1 row)

DELETE FROM the_table WHERE a = 1;
SELECT * FROM the_table;
 a | b | z
---------------------------------------------------------------------
(0 rows)

-- drawing from a sequence is not possible
INSERT INTO the_table (a, b) VALUES (1, 2);
ERROR:  cannot assign TransactionIds during recovery
-- 2PC is not possible
INSERT INTO the_table (a, b, z) VALUES (2, 3, 4), (5, 6, 7);
ERROR:  cannot assign TransactionIds during recovery
-- COPY is not possible in 2PC mode
COPY the_table (a, b, z) FROM STDIN WITH CSV;
ERROR:  cannot assign TransactionIds during recovery
-- 1PC is possible
SET citus.multi_shard_commit_protocol TO '1pc';
INSERT INTO the_table (a, b, z) VALUES (2, 3, 4), (5, 6, 7);
SELECT * FROM the_table ORDER BY a;
 a | b | z
---------------------------------------------------------------------
 2 | 3 | 4
 5 | 6 | 7
(2 rows)

-- modifying CTEs are possible
WITH del AS (DELETE FROM the_table RETURNING *)
SELECT * FROM del ORDER BY a;
 a | b | z
---------------------------------------------------------------------
 2 | 3 | 4
 5 | 6 | 7
(2 rows)

-- COPY is possible in 1PC mode
COPY the_table (a, b, z) FROM STDIN WITH CSV;
SELECT * FROM the_table ORDER BY a;
 a  | b  | z
---------------------------------------------------------------------
 10 | 10 | 10
 11 | 11 | 11
(2 rows)

DELETE FROM the_table;
-- DDL is not possible
TRUNCATE the_table;
ERROR:  cannot execute TRUNCATE TABLE in a read-only transaction
ALTER TABLE the_table ADD COLUMN c int;
ERROR:  cannot acquire lock mode AccessExclusiveLock on database objects while recovery is in progress
HINT:  Only RowExclusiveLock or less can be acquired on database objects during recovery.
-- rollback is possible
BEGIN;
INSERT INTO the_table (a, b, z) VALUES (1, 2, 2);
ROLLBACK;
SELECT * FROM the_table ORDER BY a;
 a | b | z
---------------------------------------------------------------------
(0 rows)

-- we should still disallow writes to local tables
INSERT INTO local VALUES (1, 1);
ERROR:  cannot execute INSERT in a read-only transaction
INSERT INTO local SELECT a, b FROM the_table;
ERROR:  cannot execute INSERT in a read-only transaction
-- we shouldn't be able to create local tables
CREATE TEMP TABLE local_copy_of_the_table AS SELECT * FROM the_table;
ERROR:  cannot execute CREATE TABLE AS in a read-only transaction
\c "port=9070 dbname=regression options='-c\ citus.use_secondary_nodes=always\ -c\ citus.cluster_name=second-cluster'"
-- separate follower formations currently cannot do writes
SET citus.writable_standby_coordinator TO on;
INSERT INTO the_table (a, b, z) VALUES (1, 2, 3);
ERROR:  writing to worker nodes is not currently allowed
DETAIL:  citus.use_secondary_nodes is set to 'always'
SELECT * FROM the_table ORDER BY a;
 a | b | z
---------------------------------------------------------------------
(0 rows)

\c - - - :master_port
DROP TABLE the_table;