postgresql/contrib/test_decoding/sql/slot.sql

SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot_p', 'test_decoding');
SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot_t', 'test_decoding', true);

SELECT pg_drop_replication_slot('regression_slot_p');
SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot_p', 'test_decoding', false);

-- here we want to start a new session and wait till old one is gone
select pg_backend_pid() as oldpid \gset
\c -
do 'declare c int = 0;
begin
  while (select count(*) from pg_stat_activity where pid = '
    :'oldpid'
  ') > 0 loop c := c + 1; perform pg_stat_clear_snapshot(); end loop;
  raise log ''slot test looped % times'', c;
end';

-- should fail because the temporary slot was dropped automatically
SELECT pg_drop_replication_slot('regression_slot_t');

-- permanent slot has survived
SELECT pg_drop_replication_slot('regression_slot_p');

-- test switching between slots in a session
SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot1', 'test_decoding', true);
SELECT 'init' FROM pg_create_logical_replication_slot('regression_slot2', 'test_decoding', true);
SELECT * FROM pg_logical_slot_get_changes('regression_slot1', NULL, NULL);
SELECT * FROM pg_logical_slot_get_changes('regression_slot2', NULL, NULL);