DECLARE
     new_copy_location INT;
 BEGIN
     IF (TG_OP = 'UPDATE') THEN
         IF NEW.location = OLD.location AND NEW.call_number = OLD.call_number AND NEW.circ_lib = OLD.circ_lib THEN
             RETURN NEW;
         END IF;
     END IF;
     SELECT INTO new_copy_location acpl.id FROM asset.copy_location acpl JOIN actor.org_unit_ancestors_distance((SELECT owning_lib FROM asset.call_number WHERE id = NEW.call_number)) aouad ON acpl.owning_lib = aouad.id WHERE deleted IS FALSE AND name = (SELECT name FROM asset.copy_location WHERE id = NEW.location) ORDER BY distance LIMIT 1;
     IF new_copy_location IS NULL THEN
         SELECT INTO new_copy_location acpl.id FROM asset.copy_location acpl JOIN actor.org_unit_ancestors_distance(NEW.circ_lib) aouad ON acpl.owning_lib = aouad.id WHERE deleted IS FALSE AND name = (SELECT name FROM asset.copy_location WHERE id = NEW.location) ORDER BY distance LIMIT 1;
     END IF;
     IF new_copy_location IS NOT NULL THEN
         NEW.location = new_copy_location;
     END IF;
     RETURN NEW;
 END;