[42501] ERROR: permission denied for table log

CREATE ROLE tbl_owners;
GRANT tbl_owners TO current_user;

CREATE TABLE parent (
    id SERIAL PRIMARY KEY
);

ALTER TABLE parent OWNER TO tbl_owners;

CREATE TABLE child (
    id SERIAL PRIMARY KEY,
    parent_id INTEGER,
    CONSTRAINT fk_parent FOREIGN KEY (parent_id) 
        REFERENCES parent(id) ON UPDATE CASCADE ON DELETE CASCADE DEFERRABLE INITIALLY DEFERRED
);

ALTER TABLE child OWNER TO tbl_owners; --Вот тут проблема! Если убрать, то все работает. Почему?

CREATE TABLE log (
    id SERIAL PRIMARY KEY,
    message TEXT
);

CREATE OR REPLACE FUNCTION add_log() RETURNS TRIGGER LANGUAGE plpgsql AS
$$
BEGIN
  INSERT INTO log (message) VALUES (TG_RELNAME || ' logged');
  RETURN NULL;
END;
$$;

CREATE TRIGGER log_parent
  BEFORE DELETE
    ON parent
EXECUTE PROCEDURE add_log();

CREATE TRIGGER log_child
  BEFORE DELETE
    ON child
EXECUTE PROCEDURE add_log();


INSERT INTO parent (id) VALUES (1);
INSERT INTO child (parent_id) VALUES (1);

DELETE FROM parent; --Эта команда вызывает ошибку.