Oracle用户锁定等操作
今天需要对用户进行锁定操作，发现居然不知道操作的命令格式，找来找去也没找到，还是上网查一下。其实只是一个简单的操作，就是修改密码、用户锁定、密码过期这3个操作，为了避免忘记，特地在这里记一下。最后还附有Oracle默认安装后的用户及意义，也了解一下。
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Change Oracle passwords, expire, and lock unnecessary users
There are many users on a full installation of Oracle, most of which you probably won't need. To lock an Oracle user account, you can use the following command:
alter user username account lock;
To unlock the user, simply replace 'lock' with 'unlock'.
Oracle comes with a few default accounts that should never be locked or dropped. These include: SYS, SYSTEM, SYSMAN (Oracle 10g), OUTLN(can't?). However, you do want always to change the password for these users. The default password for SYS is change_on_install. It is important that you follow these directions. To change the password for a user:
alter user username identified by new_password;
For non-critical users, you can always lock and expire the account. We can change the password for, lock, and expire the account CTXSYS all at once:
alter user ctxsys identified by 0bscur3 account lock password expire;
This will ensure that CTXSYS password has been changed from the self evident default of CTXSYS; on a successful login the password will have to be changed (because it is expired); and because it is locked, he account can't be logged into under any circumstances.
To aid you in this task, here is a list of users that come with a full database installation that are safe to expire and lock if you are not using their functionality:
AURORA$ORB$UNAUTHENTICATED - Jserver user
BI - demo user
CTXSYS - Oracle Text/interMedia administrator
DBSNMP - Oracle Intelligent Agent
DSSYS - Dynamic Services and Syndication Server
HR - demo user
MDSYS - Spatial administrator
ORDSYS/ORDPLUGIN - Object Relational Data user
OE - demo user
PERFSTAT - Statspack administrative user
SCOTT - demo user
SH - demo user
TRACESVR - Oracle trace server
WKSYS - Ultrasearch administrator
The best rule of thumb is to install only the features you need when you install Oracle. If you are not going to use Spatial, interMedia, or UltraSearch, don't install them. Then you will not have to worry about those three users.