讲解Oracle数据库的sysdba权限登录问题

　　sysdba权限的登录测试：

　　数据库用sysdba登录的验证有两种方式，一种是通过os认证，一种是通过密码文件验证；登录方式有两种，一种是在数据库主机直接登录（用os认证的方式），一种是通过网络远程登录；需要设置的参数有两个，一个是SQLNET.AUTHENTICATION_SERVICES，一个是REMOTE_LOGIN_PASSWORDFILE。

　　os认证：假如启用了os认证，以sysdba登录，那么只需要使用Oracle软件的安装用户就能登录：sqlplus “/ as sysdba”。如果我们要禁用os认证，只利用密码文件登录，我们首先要有一个密码文件：

　　D:/oracle/ora92/database>orapwd file=PWDoralocal.ora password=mypassword entries=10;

　　D:/oracle/ora92/database>

　　然后我们要把$ORACLE_HOME/network/admin/sqlnet.ora中设置：

　　SQLNET.AUTHENTICATION_SERVICES= none

　　大家需要注意，密码文件只在数据库启动的时候加载进去，一旦加载进去，密码文件就脱离了oracle管理，所以在你使用orapwd新建密码文件后，里面指定的密码需要在数据重启后才能发生作用：

　　D:/oracle/ora92/database>sqlplus "sys/mypassword as sysdba"

　　SQL*Plus: Release 9.2.0.1.0 - Production on Fri May 16 21:59:42 2008

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

　　ERROR:

　　ORA-01031: insufficient privileges

　　Enter user-name:

　　ERROR:

　　ORA-01017: invalid username/password; logon denied

　　Enter user-name:

　　ERROR:

　　ORA-01017: invalid username/password; logon denied

　　SP2-0157: unable to CONNECT to ORACLE after 3 attempts, exiting SQL*Plus

　　### 这里我们通过改SQLNET.AUTHENTICATION_SERVICES= （NTS）用os认证登录数据库：

　　sys@ORALOCAL(192.168.50.29)> shutdown immediate;

　　Database closed.

　　Database dismounted.

　　ORACLE instance shut down.

　　sys@ORALOCAL(192.168.50.29)>

　　sys@ORALOCAL(192.168.50.29)>

　　sys@ORALOCAL(192.168.50.29)>

　　sys@ORALOCAL(192.168.50.29)> startup

　　ORACLE instance started.

　　Total System Global Area 135338868 bytes

　　Fixed Size 453492 bytes

　　Variable Size 109051904 bytes

　　Database Buffers 25165824 bytes

　　Redo Buffers 667648 bytes

　　Database mounted.

　　Database opened.

　　sys@ORALOCAL(192.168.50.29)>

　　sys@ORALOCAL(192.168.50.29)>

　　sys@ORALOCAL(192.168.50.29)>

　　sys@ORALOCAL(192.168.50.29)> exit

　　Disconnected from 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

　　D:/oracle/ora92/database>

　　D:/oracle/ora92/database>

　　D:/oracle/ora92/database>

　　### 我们把SQLNET.AUTHENTICATION_SERVICES= （NTS）改回去。

　　D:/oracle/ora92/database>sqlplus "/ as sysdba"

　　SQL*Plus: Release 9.2.0.1.0 - Production on Fri May 16 22:03:59 2008

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

　　ERROR:

　　ORA-01031: insufficient privileges

　　Enter user-name:

　　ERROR:

　　ORA-01017: invalid username/password; logon denied

　　Enter user-name:

　　ERROR:

　　ORA-01017: invalid username/password; logon denied

　　SP2-0157: unable to CONNECT to ORACLE after 3 attempts, exiting SQL*Plus

　　D:/oracle/ora92/database>

　　D:/oracle/ora92/database>

　　D:/oracle/ora92/database>

　　D:/oracle/ora92/database>sqlplus "sys/mypassword as sysdba"

　　SQL*Plus: Release 9.2.0.1.0 - Production on Fri May 16 22:04:07 2008

　　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

　　sys@ORALOCAL(192.168.50.29)> exit

　　在这里，我们看到这个新改的密码要数据库重启后加载才生效。同时我们看到，用os认证是无法登录的，但是通过网络（用@sid）是可以登录。

　　D:/oracle/ora92/database>sqlplus "/ as sysdba"

　　SQL*Plus: Release 9.2.0.1.0 - Production on Sat May 17 00:58:32 2008

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

　　ERROR:

　　ORA-01031: insufficient privileges

　　Enter user-name:

　　ERROR:

　　ORA-01017: invalid username/password; logon denied

　　Enter user-name:

　　ERROR:

　　ORA-01017: invalid username/password; logon denied

　　SP2-0157: unable to CONNECT to ORACLE after 3 attempts, exiting SQL*Plus

　　D:/oracle/ora92/database>

　　D:/oracle/ora92/database>sqlplus "sys/mypassword as sysdba"

　　SQL*Plus: Release 9.2.0.1.0 - Production on Sat May 17 00:59:15 2008

　　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

　　sys@ORALOCAL(192.168.50.29)>

　　sys@ORALOCAL(192.168.50.29)>

　　sys@ORALOCAL(192.168.50.29)> exit

　　Disconnected from 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

　　D:/oracle/ora92/database>sqlplus "sys/mypassword@oralocal as sysdba"

　　SQL*Plus: Release 9.2.0.1.0 - Production on Sat May 17 00:59:38 2008

　　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

　　sys@ORALOCAL(192.168.50.29)>