remote_os_authent概述
Oracle允许用户通过采用外部验证的方式登录数据库。默认情况下，只允许本机的用户采用外部验证登录到数据库中。当将remote_os_authent这个参数设置为true时，则允许远端用户采用外部验证的方式登录到数据库中。
关于外部验证，请参见笔者的下面文章
http://czmmiao.iteye.com/blog/1239822
示例如下
target数据库上
SQL> show parameter os_aut
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
os_authent_prefix string
remote_os_authent boolean TRUE
SQL> select instance_name from v$instance;
INSTANCE_NAME
----------------
czmmiao
source数据库上
[hr@ha2 ~]$ id
uid=501(hr) gid=503(hr) groups=501(oinstall),503(hr)
连接到target数据库，其中oookkk为tnsname.ora中的连接字符串
[hr@ha2 ~]$ sqlplus /@oookkk
SQL*Plus: Release 10.2.0.1.0 - Production on Mon Nov 7 17:37:05 2011
Copyright (c) 1982, 2005, Oracle. All rights reserved.
Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options
SQL> show user;
USER is "HR"
SQL> select instance_name from v$instance;
INSTANCE_NAME
----------------
czmmiao
将target数据库上的remote_os_authent设置为false
SQL> alter system set remote_os_authent=false scope=spfile;
System altered.
SQL> startup force;
ORACLE instance started.
Total System Global Area 373293056 bytes
Fixed Size 1219496 bytes
Variable Size 201327704 bytes
Database Buffers 167772160 bytes
Redo Buffers 2973696 bytes
Database mounted.
Database opened.
SQL> show parameter remote_os_authent
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
remote_os_authent boolean FALSE
从source数据库登录到target数据库
[hr@ha2 ~]$ sqlplus /@oookkk
SQL*Plus: Release 10.2.0.1.0 - Production on Mon Nov 7 17:39:52 2011
Copyright (c) 1982, 2005, Oracle. All rights reserved.
ERROR:
ORA-01017: invalid username/password; logon denied
