今天看书偶尔看到以受限模式(restrict)打开资料库，或者把数据库处于受限模式，这样可以很方便地在特殊情况对数据库进行操作。所谓受限就是只有拥有权限的人才能访问数据库。

使数据库处于受限模式，有以下二种方法

1) STARTUP RESTRICT

2) ALTER SYSTEM ENABLE RESTRICTED SESSION;

对于第二种情况，只能使发布命令后的登陆生效，因此如果对于这种情况，一般会杀掉前面已经登陆的进程！

[@more@]

-- STARTUP RESTRICT 方式

SYS@HUIYI>shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SYS@HUIYI>startup restrict;
ORACLE instance started.

Total System Global Area  135338868 bytes
Fixed Size                   453492 bytes
Variable Size             113246208 bytes
Database Buffers           20971520 bytes
Redo Buffers                 667648 bytes
Database mounted.
Database opened.

D:>sqlplus scott/tiger

SQL*Plus: Release 9.2.0.1.0 - Production on Mon Mar 26 20:13:08 2007

Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved.

ERROR:
ORA-01035: ORACLE only available to users with RESTRICTED SESSION privilege

-- 给SCOTT赋权
SYS@HUIYI>grant restricted session to scott;

Grant succeeded.

D:>sqlplus scott/tiger

SQL*Plus: Release 9.2.0.1.0 - Production on Mon Mar 26 20:19:10 2007

Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved.


Connected to:
Oracle9i Enterprise Edition Release 9.2.0.1.0 - Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.1.0 - Production

SCOTT@HUIYI>select * from session_privs where privilege like 'RES%';

PRIVILEGE
----------------------------------------
RESTRICTED SESSION



-- ALTER SYSTEM 方式

SYS@HUIYI>startup force;
ORACLE instance started.

Total System Global Area  135338868 bytes
Fixed Size                   453492 bytes
Variable Size             113246208 bytes
Database Buffers           20971520 bytes
Redo Buffers                 667648 bytes
Database mounted.
Database opened.
SYS@HUIYI>revoke restricted session from scott;

Revoke succeeded.

SYS@HUIYI>alter system enable restricted session;

System altered.

D:>sqlplus scott/tiger

SQL*Plus: Release 9.2.0.1.0 - Production on Mon Mar 26 20:35:59 2007

Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved.

ERROR:
ORA-01035: ORACLE only available to users with RESTRICTED SESSION privilege

-- 取消受限
SYS@HUIYI>alter system disable restricted session;

System altered.

D:>sqlplus scott/tiger

SQL*Plus: Release 9.2.0.1.0 - Production on Mon Mar 26 20:37:51 2007

Copyright (c) 1982, 2002, Oracle Corporation.  All rights reserved.


Connected to:
Oracle9i Enterprise Edition Release 9.2.0.1.0 - Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.1.0 - Production

SCOTT@HUIYI>