如何禁用普通用户查看所有用户名

郑全

不知道大家注意到没有，只有能登录数据库，就可以看到系统中有哪些用户，比如：

create user test identified by test;
grant create session to test;

conn test/test;

就可以看到所有用户：
select * from all_users;

由于系统中大部分用户密码是弱密码，甚至部分密码和用户名一样，就容易给部分别有用心的用户以可乘之机。

如何关闭这种情况呢，让普通用户不能查看系统中有哪些用户？

答案是肯定的。

郑全

嗯，谢谢。

denglj

系统：CentOS 7.6
数据库：11.2.0.4
SQL> create user xiaoqiang identified by xiaoqiang default tablespace users;

User created.

SQL> grant create session to xiaoqiang;

Grant succeeded.

SQL> conn xiaoqiang/xiaoqiang;
Connected.
SQL> select username from all_users where rownum<=2;

USERNAME
------------------------------
SYS
SYSTEM

SQL> conn / as sysdba
Connected.
SQL> revoke select on sys.all_users from public;

Revoke succeeded.

SQL> conn xiaoqiang/xiaoqiang;
Connected.
SQL> select username from all_users;
select username from all_users

ERROR at line 1:
ORA-00942: table or view does not exist

SQL> conn / as sysdba
Connected.
SQL> create user xiaohua identified by xiaohua;

User created.

SQL> grant create session to xiaohua;

Grant succeeded.

SQL> conn xiaohua/xiaohua;
Connected.
SQL> select count(*) from all_users;
select count(*) from all_users
                     *
ERROR at line 1:
ORA-00942: table or view does not exist

SQL> conn / as sysdba
Connected.
SQL> select username,account_status from dba_users where username='SCOTT';

USERNAME                       ACCOUNT_STATUS
------------------------------ --------------------------------
SCOTT                          EXPIRED & LOCKED

SQL> alter user scott account unlock;

User altered.

SQL> alter user scott identified by scott;

User altered.

SQL> select count(*) from all_users;
select count(*) from all_users
                     *
ERROR at line 1:
ORA-00942: table or view does not exist