Функция plpgsql с циклом по таблице

CREATE OR REPLACE FUNCTION public.test_table_iterator()
  RETURNS void AS
$BODY$
DECLARE
  r record;
BEGIN
  FOR r IN SELECT * FROM customers LOOP
    RAISE NOTICE 'name: % name: %', r.name, r.age;
  END LOOP;
END;
$BODY$
  LANGUAGE plpgsql VOLATILE