Hi. Bug or feature? CREATE FUNCTION upd (text, text) RETURNS text AS ' BEGIN RETURN $1; END ' LANGUAGE 'plpgsql'; SELECT upd('aaa','bbb'); aaa SELECT upd(null,'bbb'); <null> All seems ok, but how about next ? SELECT upd('aaa',null); <null> -- С уважением, Ващенко Максим, Нижегородские информационные сети (8312) 30-19-05, 34-00-02, 30-09-73 With best regards, Max Vaschenko, Nizhny Novgorod Information Networks.