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:oracleora92database>orapwd file=PWDoralocal.ora password=mypassword entries=10;
D:oracleora92database>
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:oracleora92database>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:oracleora92database>
D:oracleora92database>
D:oracleora92database>
### 我们把SQLNET.AUTHENTICATION_SERVICES= （NTS）改回去。
D:oracleora92database>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:oracleora92database>
D:oracleora92database>
D:oracleora92database>
D:oracleora92database>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:oracleora92database>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:oracleora92database>
D:oracleora92database>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:oracleora92database>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)>
至此，我们已经实现不用os认证（sqlplus “/ as sysdba”的方式登录不了）。那么我们怎么限制网络方面利用sysdba远程登录呢？我们可以设置初始化文件中的REMOTE_LOGIN_PASSWORDFILE=none。
注意，当REMOTE_LOGIN_PASSWORDFILE=none时，这个参数生效需要重启数据库，并且，一旦启用这个参数，将使用操作系统认证，不使用口令文件。因此如果REMOTE_LOGIN_PASSWORDFILE=none且SQLNET.AUTHENTICATION_SERVICES= none这个时候数据库是无法登录的。
[coolcode lang=”sql” linenum=”off”]
D:oracleora92database>sqlplus “sys/change_on_install as sysdba”
SQL*Plus: Release 9.2.0.1.0 - Production on Sat May 17 01:28:58 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)> show parameter remote_login
NAME TYPE VALUE
———————————— ———– ——————————
remote_login_passwordfile string EXCLUSIVE
sys@ORALOCAL(192.168.50.29)> alter system set remote_login_passwordfile=none scope=spfile;
System altered.
Elapsed: 00:00:00.01
sys@ORALOCAL(192.168.50.29)> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
sys@ORALOCAL(192.168.50.29)> startup
ORA-01031: insufficient privileges
sys@ORALOCAL(192.168.50.29)>exit
C:Documents and SettingsAdministrator>sqlplus “/ as sysdba”
SQL*Plus: Release 9.2.0.1.0 - Production on Sat May 17 08:26:43 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
C:Documents and SettingsAdministrator>sqlplus “sys/change_on_install as sysdba”
SQL*Plus: Release 9.2.0.1.0 - Production on Sat May 17 08:26:53 2008
Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.
ERROR:
ORA-01017: invalid username/password; logon denied
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
C:Documents and SettingsAdministrator>
C:Documents and SettingsAdministrator>sqlplus “sys/change_on_install@oralocal as sysdba”
SQL*Plus: Release 9.2.0.1.0 - Production on Sat May 17 08:27:03 2008
Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.
ERROR:
ORA-01017: invalid username/password; logon denied
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
C:Documents and SettingsAdministrator>
[coolcode]
这里我们看到由于启用了REMOTE_LOGIN_PASSWORDFILE=none，使用os认证，不用密码文件认证，必须将SQLNET.AUTHENTICATION_SERVICES= none取消，不然是无法登录。我们改成SQLNET.AUTHENTICATION_SERVICES= （NTS）后再次测试。
[coolcode lang=”sql” linenum=”off”]
### 非oracle软件安装软件用户：###
C:Documents and Settingshejianmin>sqlplus “/ as sysdba”
SQL*Plus: Release 9.2.0.1.0 - Production on Sat May 17 20:15:13 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
C:Documents and Settingshejianmin>
C:Documents and Settingshejianmin>sqlplus “sys/change_on_install as sysdba”
SQL*Plus: Release 9.2.0.1.0 - Production on Sat May 17 20:15:30 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
C:Documents and Settingshejianmin>
C:Documents and Settingshejianmin>sqlplus “sys/change_on_install@oralocal as sysdba”
SQL*Plus: Release 9.2.0.1.0 - Production on Sat May 17 20:15:42 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
C:Documents and Settingshejianmin>
### oracle 软件安装用户 ####
C:Documents and SettingsAdministrator>sqlplus “/ as sysdba”
SQL*Plus: Release 9.2.0.1.0 - Production on 星期六 5月 17 20:19:13 2008
Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.
连接到:
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(192.168.0.29)> exit
从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中断开
C:Documents and SettingsAdministrator>sqlplus “sys/change_on_install as sysdba”
SQL*Plus: Release 9.2.0.1.0 - Production on 星期六 5月 17 20:19:33 2008
Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.
连接到:
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(192.168.0.29)> exit
从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中断开
C:Documents and SettingsAdministrator>sqlplus “sys/change_on_install@oralocal as sysdba”
SQL*Plus: Release 9.2.0.1.0 - Production on 星期六 5月 17 20:19:45 2008
Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.
连接到:
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(192.168.0.29)> exit
从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中断开
C:Documents and SettingsAdministrator>sqlplus “11/22 as sysdba”
SQL*Plus: Release 9.2.0.1.0 - Production on 星期六 5月 17 20:19:58 2008
Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.
连接到:
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(192.168.0.29)>
[/coolcode]
在这里我们看到由于用了os认证，在oracle安装用户下，无论用什么方式都能登录。非oracle用户无论用什么用户都无法登录。
如果REMOTE_LOGIN_PASSWORDFILE=exclusive且SQLNET.AUTHENTICATION_SERVICES= none时：
[coolcode lang=”sql” linenum=”off”]
C:Documents and SettingsAdministrator>sqlplus “sys/change_on_install as sysdba”
SQL*Plus: Release 9.2.0.1.0 - Production on Sat May 17 20:30:57 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(192.168.0.29)> 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
C:Documents and SettingsAdministrator>
C:Documents and SettingsAdministrator>sqlplus “/ as sysdba”
SQL*Plus: Release 9.2.0.1.0 - Production on Sat May 17 20:31:04 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
C:Documents and SettingsAdministrator>
C:Documents and SettingsAdministrator>
[/coolcode]
结论：
（1）REMOTE_LOGIN_PASSWORDFILE=none且SQLNET.AUTHENTICATION_SERVICES= none：
oracle安装用户本地sqlplus “/ as sysdba”无法登录
非oracle安装用户本机sqlplus “sys/change_on_install as sysdba”无法登录
非oracle安装用户远程sqlplus “/ as sysdba_on_install@sid as sysdba”无法登录
（2）REMOTE_LOGIN_PASSWORDFILE=exclusive且SQLNET.AUTHENTICATION_SERVICES= none：
oracle安装用户本地sqlplus “/ as sysdba”无法登录
非oracle安装用户本机sqlplus “sys/change_on_install as sysdba”能登录
非oracle安装用户远程sqlplus “/ as sysdba_on_install@sid as sysdba”能登录
（3）REMOTE_LOGIN_PASSWORDFILE=none且SQLNET.AUTHENTICATION_SERVICES= (NTS)：
oracle安装用户本地sqlplus “/ as sysdba”能登录
非oracle安装用户本机sqlplus “sys/change_on_install as sysdba”无法登录
非oracle安装用户远程sqlplus “/ as sysdba_on_install@sid as sysdba”无法登录
（4）REMOTE_LOGIN_PASSWORDFILE=exclusive且SQLNET.AUTHENTICATION_SERVICES= (NTS)：
oracle安装用户本地sqlplus “/ as sysdba”能登录
非oracle安装用户本机sqlplus “sys/change_on_install as sysdba”能登录
非oracle安装用户远程sqlplus “/ as sysdba_on_install@sid as sysdba”能登录
