在11.1.0.6上进行的测试：

SQL> create table t (id number);

表已创建。

SQL> create trigger t              
  2  before update of id on t
  3  for each row
  4  begin
  5  :new.id := 1;
  6  end;
  7  /

触发器已创建

SQL> col object_name format a30
SQL> select object_name, object_type, status
  2  from user_objects
  3  where object_name = 'T';

OBJECT_NAME                    OBJECT_TYPE                            STATUS
------------------------------ -------------------------------------- --------------
T                              TABLE                                  VALID
T                              TRIGGER                                VALID

SQL> alter table t add name varchar2(30);

表已更改。

SQL> select object_name, object_type, status
  2  from user_objects
  3  where object_name = 'T';

OBJECT_NAME                    OBJECT_TYPE                            STATUS
------------------------------ -------------------------------------- --------------
T                              TABLE                                  VALID
T                              TRIGGER                                INVALID

SQL> select * from v$version;

BANNER
-----------------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.1.0.6.0 - 64bit Production
PL/SQL Release 11.1.0.6.0 - Production
CORE    11.1.0.6.0      Production
TNS for Solaris: Version 11.1.0.6.0 - Production
NLSRTL Version 11.1.0.6.0 - Production

可以看到虽然触发器明确指明了依赖T的ID列，但是如果T表新增了其他列，仍然会导致触发器被置于INVALID状态。

而在11.2中：

SQL> create table t(id number);

表已创建。

SQL> create trigger t
  2  before update of id on t
  3  for each row
  4  begin
  5  :new.id := 1;
  6  end;
  7  /

触发器已创建

SQL> select object_name, object_type, status
  2  from user_objects
  3  where object_name = 'T';

OBJECT_NAME                    OBJECT_TYPE         STATUS
------------------------------ ------------------- -------
T                              TRIGGER             VALID
T                              TABLE               VALID

SQL> alter table t add name varchar2(30);

表已更改。

SQL> select object_name, object_type, status
  2  from user_objects
  3  where object_name = 'T';

OBJECT_NAME                    OBJECT_TYPE         STATUS
------------------------------ ------------------- -------
T                              TRIGGER             VALID
T                              TABLE               VALID

SQL> select * from v$version;

BANNER
--------------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.2.0.1.0 - 64bit Production
PL/SQL Release 11.2.0.1.0 - Production
CORE    11.2.0.1.0      Production
TNS for Linux: Version 11.2.0.1.0 - Production
NLSRTL Version 11.2.0.1.0 - Production

显然列级依赖的问题已经实现。