Oracle中password file的作用及说明

在数据库没有启动之前，数据库内建用户是无法通过数据库来验证身份的

口令文件中存放sysdba/sysoper用户的用户名及口令
允许用户通过口令文件验证，在数据库未启动之前登陆
从而启动数据库

如果没有口令文件，在数据库未启动之前就只能通过操作系统认证.

使用Rman，很多时候需要在nomount,mount等状态对数据库进行处理
所以通常要求sysdba权限如果属于本地DBA组，可以通过操作系统认证登陆
如果是远程sysdba登陆，需要通过passwordfile认证.

1.remote_login_passwordfile = NONE

此时停用口令文件验证，Oracle数据库不允许远程SYSDBA/SYSOPER身份登录
无法通过远程进行数据库起停等操作管理

local:

[oracle@jumper oracle]$ sqlplus "/ as sysdba"

SQL*Plus: Release 9.2.0.3.0 - Production on Thu Apr 15 09:58:45 2004

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


Connected to:
Oracle9i Enterprise Edition Release 9.2.0.3.0 - Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.3.0 - Production

SQL> alter user sys identified by oracle;

User altered.

SQL> show parameter pass

NAME                      TYPE   VALUE
--------------------- ----------- ------------------------------
remote_login_passwordfile string NONE
   
   

remote:

E:\Oracle\ora92\bin>sqlplus /nolog

SQL*Plus: Release 9.2.0.4.0 - 
Production on 星期四 4月 15 09:39:22 2004

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

SQL> connect sys/oracle@hsjf as 
sysdba
ERROR:
ORA-01017: invalid username/password; logon denied

此处实际上是无法通过口令文件验证

2.remote_login_passwordfile = exclusive

SQL> alter system set remote_login_passwordfile=exclusive scope=spfile;

System altered.

SQL> startup force;
ORACLE instance started.

Total System Global Area 131142648 bytes
Fixed Size 451576 bytes
Variable Size 104857600 bytes
Database Buffers 25165824 bytes
Redo Buffers 667648 bytes
Database mounted.
Database opened.
SQL> show parameter pass

NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
remote_login_passwordfile string EXCLUSIVE
SQL> alter user sys identified by oracle;

User altered.

remote:

E:\Oracle\ora92\bin>sqlplus /nolog

SQL*Plus: Release 9.2.0.4.0 - 
Production on 星期四 4月 15 09:47:11 2004

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

SQL> connect sys/oracle@hsjf as 
sysdba
已连接。
SQL> show user
USER 为"SYS"
SQL>

这实际上就是通过口令文件验证登录的

3.进一步测试

如果此时我们删除passwdfile,sysdba/sysoper将无法认证，也就无法登陆数据库

Server:

SQL> !
[oracle@jumper oracle]$ cd $ORACLE_HOME/dbs
[oracle@jumper dbs]$ ls orapwhsjf
orapwhsjf
[oracle@jumper dbs]$ mv orapwhsjf orapwhsjf.bak
[oracle@jumper dbs]$ 

Remote: 

E:\Oracle\ora92\bin>sqlplus /nolog

SQL*Plus: Release 9.2.0.4.0 - Production on 星期四 4月 15 09:50:14 2004

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

SQL> connect sys/oracle@hsjf as sysdba
ERROR:
ORA-01031: insufficient privileges


SQL>

这实际上就是无法通过口令文件验证身份

4.如果丢失了passwdfile

如果使用passwdfile却意外丢失，此时将不能启动数据库

SQL> startup force;
ORACLE instance started.

Total System Global Area 131142648 bytes
Fixed Size 451576 bytes
Variable Size 104857600 bytes
Database Buffers 25165824 bytes
Redo Buffers 667648 bytes
ORA-01990: error opening password file ‘/opt/oracle/product/9.2.0/dbs/orapw‘
ORA-27037: unable to obtain file status
Linux Error: 2: No such file or directory
Additional information: 3

此时可以通过orapwd重建口令文件来解决
此处我们恢复口令文件既可

SQL> !
[oracle@jumper oracle]$ mv $ORACLE_HOME/dbs/orapwhsjf.bak orapwhsjf
[oracle@jumper oracle]$ exit
exit

SQL> alter database open;

Database altered.

SQL>

大致就是如此.

5. remote_login_passwordfile = shared

我们看一下Oracle9i文档中的说明:

SHARED

More than one database can use a password file. However, the only user recognized by the password file is SYS.

意思是说多个数据库可以共享一个口令文件,但是只可以识别一个用户:SYS

SQL> select * from v$pwfile_users;

USERNAME SYSDB SYSOP
------------------------------ ----- -----
SYS TRUE TRUE

SQL> grant sysdba to eygle;
grant sysdba to eygle
*
ERROR at line 1:
ORA-01994: GRANT failed: cannot add users to public password file

SQL> show parameter password

NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
remote_login_passwordfile string SHARED

我们看到,此时的口令文件中是不能添加用户的.

很多人的疑问在于:口令文件的缺省名称是orapw<sid>,怎么能够共享?

实际上是这样的: Oracle数据库在启动时,首先查找的是orapw<sid>的口令文件,如果该文件不存在,则开始查找,orapw的口令文件
如果口令文件命名为orapw,多个数据库就可以共享.

我们看一下测试:

[oracle@jumper dbs]$ sqlplus "/ as sysdba"

SQL*Plus: Release 9.2.0.3.0 - Production on Tue Jul 6 09:40:34 2004

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


Connected to:
Oracle9i Enterprise Edition Release 9.2.0.3.0 - Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.3.0 - Production

SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> !
[oracle@jumper dbs]$ ls
hsjf  initdw.ora  inithsjf.ora  init.ora  lkHSJF  orapwhsjf  spfilehsjf.ora
[oracle@jumper dbs]$ mv orapwhsjf orapwhsjf.bak
[oracle@jumper dbs]$ exit
exit

SQL> startup
ORACLE instance started.

Total System Global Area  235999908 bytes
Fixed Size                   451236 bytes
Variable Size             201326592 bytes
Database Buffers           33554432 bytes
Redo Buffers                 667648 bytes
ORA-01990: error opening password file ‘/opt/oracle/product/9.2.0/dbs/orapw‘--这是最后查找的文件
ORA-27037: unable to obtain file status
Linux Error: 2: No such file or directory
Additional information: 3

    

我们建立orapw口令文件,这时候可以打开数据库.

SQL> !
[oracle@jumper dbs]$ ls
hsjf  initdw.ora  inithsjf.ora  init.ora  lkHSJF  orapwhsjf.bak  spfilehsjf.ora
[oracle@jumper dbs]$ cp orapwhsjf.bak orapw
[oracle@jumper dbs]$ exit
exit

SQL> alter database open;

Database altered.

SQL> show parameter passw

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
remote_login_passwordfile            string      SHARED
SQL>    

那么你可能会有这样的疑问,多个Exclusive的数据库是否可以共享一个口令文件(orapw)呢?

我们继续这个实验:

SQL> show parameter password

NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
remote_login_passwordfile string SHARED

[oracle@jumper dbs]$ strings orapw
]\[Z
ORACLE Remote Password file
INTERNAL
AB27B53EDC5FEF41
8A8F025737A9097A

注意这里仅记录着INTERNAL/SYS的口令

REMOTE_LOGIN_PASSWORDFILE=EXCLUSIVE 时

SQL> alter system set remote_login_passwordfile=exclusive scope=spfile;

System altered.

SQL> startup force;
ORACLE instance started.

Total System Global Area 235999908 bytes
Fixed Size 451236 bytes
Variable Size 201326592 bytes
Database Buffers 33554432 bytes
Redo Buffers 667648 bytes
Database mounted.
Database opened.
SQL> !

[oracle@jumper bin]$ cd $ORACLE_HOME/dbs
[oracle@jumper dbs]$ strings orapw
]\[Z
ORACLE Remote Password file
HSJF
INTERNAL
AB27B53EDC5FEF41
8A8F025737A9097A
[oracle@jumper dbs]$ exit
exit

注意这里,以EXCLUSIVE 方式启动以后,实例名称信息被写入口令文件.

此时如果有其他实例以Exclusive模式启动仍然可以使用这个口令文件,口令文件中的实例名称同时被改写.

也就是说,数据库只在启动过程中才读取口令文件,数据库运行过程中并不锁定该文件,类似于pfile/spfile文件.

SQL> select * from v$pwfile_users;

USERNAME SYSDB SYSOP
------------------------------ ----- -----
SYS TRUE TRUE

SQL> grant sysdba to eygle;

Grant succeeded.

SQL> select * from v$pwfile_users;

USERNAME SYSDB SYSOP
------------------------------ ----- -----
SYS TRUE TRUE
EYGLE TRUE FALSE

SQL> !
[oracle@jumper bin]$ cd $ORACLE_HOME/dbs
[oracle@jumper dbs]$ strings orapw
]\[Z
ORACLE Remote Password file
HSJF
INTERNAL
AB27B53EDC5FEF41
8A8F025737A9097A
>EYGLE
B726E09FE21F8E83

注意此时可以增加SYSDBA用户，并且这些信息可以被写入到口令文件.

一旦口令文件中增加了其他SYSDBA用户,此文件不再能够被其他Exclusive的实例共享.

实际上，口令文件对于其他用户来说就是启到了一个 sudo 的作用.

6.重建口令文件

如果口令文件丢失,可以使用orapwd可以重建口令文件，语法如下:

[oracle@jumper oracle]$ orapwd
Usage: orapwd file=<fname> password=<password> entries=<users> 

where
file - name of password file (mand),
password - password for SYS (mand),
entries - maximum number of distinct DBA and OPERs (opt), 
There are no spaces around the equal-to (=) character.

转自：http://www.eygle.com/faq/passwordfile.htm

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