将它们放在单独的表中：

create table status (id_status) as
  select 1 from dual union all
  select 2 from dual union all
  select 3 from dual;

alter table status add constraint pk_status primary key (id_status);

将当前查询修改为

SELECT *
FROM DOCUMENTS
WHERE STATUS IN (select status from status);

一旦出现新状态，只需

insert into status (id_status) values (4);

并且所有查询-引用状态-将仍然保持工作并且不必修改。