show_trigger_table_locks.sql

DROP TABLE IF EXISTS test;

CREATE TABLE test();

CREATE OR REPLACE FUNCTION dummy_tg() RETURNS TRIGGER
LANGUAGE plpgsql AS $$ BEGIN END; $$;

BEGIN;

CREATE TRIGGER blah BEFORE INSERT ON test FOR EACH ROW EXECUTE PROCEDURE dummy_tg();

SELECT * FROM pg_locks 
WHERE pid = pg_backend_pid() 
AND relation = 'test'::regclass;

ROLLBACK;