环境：

sys@ORCL> select * from v$version where rownum=1;

BANNER
----------------------------------------------------------------
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Prod

sys@ORCL> !uname -a
Linux localhost.localdomain 2.6.18-308.el5xen #1 SMP Fri Jan 27 17:59:00 EST 2012 i686 i686 i386 GNU/Linux

    实验过程如下：

scott@ORCL> create table tvpd (name varchar2(20),salary number(8,2),department_id number(5));

Table created.

scott@ORCL> insert into tvpd values(\'张三\',5000,10);

1 row created.

scott@ORCL> insert into tvpd values(\'李四\',250,20);

1 row created.

scott@ORCL> commit;

Commit complete.


sys@ORCL> grant connect to zhangsan identified by zhangsan;

Grant succeeded.

sys@ORCL> grant select on scott.tvpd to zhangsan;

Grant succeeded.

sys@ORCL> grant connect to lisi identified by lisi;

Grant succeeded.

sys@ORCL> grant select on scott.tvpd to lisi;

Grant succeeded.

sys@ORCL> conn zhangsan/zhangsan
Connected.
zhangsan@ORCL> select * from scott.tvpd;

NAME                     SALARY DEPARTMENT_ID
-------------------- ---------- -------------
张三                       5000            10
李四                        250            20

zhangsan@ORCL> conn scott/tiger
Connected.
scott@ORCL> create or replace function func_vpd
(owner varchar2,objname varchar2)
return varchar2
is
  v_where_clause varchar2(2000);
begin
  v_where_clause :=\'name=initcap(sys_context(\'\'userenv\'\',\'\'session_user\'\'))\';
  return v_where_clause;
end;  2    3    4    5    6    7    8    9  
 10  /

Function created.

scott@ORCL> conn / as sysdba
Connected.
sys@ORCL> select * from dba_policies where object_owner=\'SCOTT\';

no rows selected

sys@ORCL> BEGIN
  dbms_rls.add_policy(object_schema => \'SCOTT\',
  object_name => \'TVPD\',
  policy_name => \'scott_policy123\',
  function_schema =>\'SCOTT\',
  policy_function => \'func_vpd\',
  statement_types  =>\'select\',
  sec_relevant_cols=>\'salary\');
END;  2    3    4    5    6    7    8    9  
 10  /

PL/SQL procedure successfully completed.

sys@ORCL> select * from dba_policies where object_owner=\'SCOTT\';

OBJECT_OWNER                   OBJECT_NAME                    POLICY_GROUP
------------------------------ ------------------------------ ------------------------------
POLICY_NAME                    PF_OWNER                       PACKAGE
------------------------------ ------------------------------ ------------------------------
FUNCTION                       SEL INS UPD DEL IDX CHK ENA STA POLICY_TYPE              LON
------------------------------ --- --- --- --- --- --- --- --- ------------------------ ---
SCOTT                          TVPD                           SYS_DEFAULT
SCOTT_POLICY123                SCOTT
FUNC_VPD                       YES NO  NO  NO  NO  NO  YES NO  DYNAMIC                  NO
scott@ORCL> conn zhangsan/zhangsan
Connected.
zhangsan@ORCL> select * from scott.tvpd;

no rows selected

zhangsan@ORCL> select name from scott.tvpd;

NAME
--------------------
张三
李四

    在本测试中，我们只是对列salary作精细化控制，如果不查工资还是可以全部看到的，正如上面所示。

    但是请注意，sys仍然不受影响，因为他有个权限叫“exempt access policy”，这个的性质和sysdba一样。

zhangsan@ORCL> conn / as sysdba
Connected.
sys@ORCL> grant exempt access policy to zhangsan;

Grant succeeded.

sys@ORCL> conn zhangsan/zhangsan
Connected.
zhangsan@ORCL> select * from scott.tvpd;

NAME                     SALARY DEPARTMENT_ID
-------------------- ---------- -------------
张三                       5000            10
李四                        250            20

    同时，受策略保护的表若被drop是不进recyclebin，也就无法用flashback ... to before drop。

zhangsan@ORCL> conn scott/tiger
Connected.
scott@ORCL> show recyclebin
scott@ORCL> drop table tvpd;

Table dropped.

scott@ORCL> show recyclebin
scott@ORCL> flashback table tvpd to before drop;
flashback table tvpd to before drop
*
ERROR at line 1:
ORA-38305: object not in RECYCLE BIN