sqlnet.ora文件为空时采用Oracle密码文件验证
SQLNET.AUTHENTICATION_SERVICES= (NTS) 基于操作系统验证；
SQLNET.AUTHENTICATION_SERVICES= (NONE) 基于Oracle密码文件验证
SQLNET.AUTHENTICATION_SERVICES= (NONE,NTS) 二者并存，注意是半角，否则不识别
sqlnet.ora示例一：
# This file is actually generated by netca. But if customers choose to
# install "Software Only", this file wont exist and without the native
# authentication, they will not be able to connect to the database on NT.
#SQLNET.AUTHENTICATION_SERVICES = (NTS)
C:\Documents and Settings\Administrator>sqlplus " / as sysdba"
SQL*Plus: Release 9.2.0.1.0 - Production on Mon May 5 17:54:32 2008
Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.
ERROR:
ORA-01031: insufficient privileges
sqlnet.ora示例二：
# This file is actually generated by netca. But if customers choose to
# install "Software Only", this file wont exist and without the native
# authentication, they will not be able to connect to the database on NT.
SQLNET.AUTHENTICATION_SERVICES = (NONE,NTS)
C:\Documents and Settings\Administrator>sqlplus " / as sysdba"
SQL*Plus: Release 9.2.0.1.0 - Production on Mon May 5 18:01:14 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
SQL>
<Unix/Linux>
默认情况下Unix/Linux下的sqlnet.ora文件是没有SQLNET.AUTHENTICATION_SERVICES参数的，
此时是操作系统验证和Oracle密码验证并存，加上SQLNET.AUTHENTICATION_SERVICES这个参
数后，不管SQLNET.AUTHENTICATION_SERVICES设置为NONE还是NTS还是(NONE,NTS)，都是
基于Oracle密码验证。
sqlnet.ora示例一：
[oracle@liwei admin]$ cat sqlnet.ora
# This file is actually generated by netca. But if customers choose to
# install "Software Only", this file wont exist and without the native
# authentication, they will not be able to connect to the database on NT.
#SQLNET.AUTHENTICATION_SERVICES = (NONE)
#SQLNET.AUTHENTICATION_SERVICES=(NTS)
SQLNET.AUTHENTICATION_SERVICES = (NONE,NTS)
[oracle@liwei oracle]$ sqlplus "/ as sysdba"
SQL*Plus: Release 10.2.0.1.0 - Production on Thu May 1 18:57:31 2008
Copyright (c) 1982, 2005, Oracle. All rights reserved.
ERROR:
ORA-01031: insufficient privileges
三、解释REMOTE_LOGIN_PASSWORDFILE参数
Parameter type
String
Syntax
REMOTE_LOGIN_PASSWORDFILE= {NONE | SHARED | EXCLUSIVE}
Default value
NONE
Parameter class
Static
Real Application Clusters
Multiple instances must have the same value.
REMOTE_LOGIN_PASSWORDFILE specifies whether Oracle checks for a password file and
how many databases can use the password file.
Values:
NONE
Oracle ignores any password file. Therefore, privileged users must be authenticated by the operating system.
SHARED
More than one database can use a password file. However, the only user recognized by the password file is SYS.
EXCLUSIVE
The password file can be used by only one database and the password file can contain names other than SYS.
顾名思义，这个参数是设置远程登录的。
alter system set remote_login_passwordfile = none scope=spfile;
NONE 很好理解，Oracle忽略所有的密码文件，只能使用操作系统身份验证。此时不能远程登录
为sysdba和sysoper角色。也不能将sysdba,sysoper授权给其他用户。
SQL> grant sysdba to system;
grant sysdba to system
*
ERROR at line 1:
ORA-01994: GRANT failed: password file missing or disabled
alter system set remote_login_passwordfile = exclusive scope=spfile;
EXCLUSIVE 最为常用，远程认证的用户可以是具有sysdba和sysoper角色的所有用户。可以通
过sysdba角色修改sys密码。一个password file只能被数据库一个instance使用。可以对其他用户
进行sysdba,sysoper授权。
SQL> grant sysoper to system;
Grant succeeded.
如果EXCLUSIVE下，密码文件丢失则数据库模式等同于NONE。
alter system set remote_login_passwordfile = shared scope=spfile;
SHARED，远程认证的用户可以是具有sysdba和sysoper角色的所有用户。不可以通过sysdba角
色修改sys密码。一个password file可以被数据库的多个instance使用，如果这个数据库有多个instance
的话，但远程认证的用户只能是具有sysdba和sysoper角色的sys用户
SQL> alter user sys identified by sys;
alter user sys identified by sys
*
ERROR at line 1:
ORA-28046: Password change for SYS disallowed
SQL> grant sysoper to system;
grant sysoper to system
*
ERROR at line 1:
ORA-01999: password file cannot be updated in SHARED mode
本文来自CSDN博客，转载请标明出处：http://blog.csdn.net/liwei_cmg/archive/2008/05/06/2403337.aspx
