在資料庫沒有啟動之前，資料庫內建使用者是無法透過資料庫來驗證身份的

口令檔案中存放sysdba/sysoper使用者的使用者名稱及口令
允許使用者透過口令檔案驗證，在資料庫未啟動之前登陸
從而啟動資料庫

如果沒有口令檔案，在資料庫未啟動之前就只能透過作業系統認證.

使用Rman，很多時候需要在nomount,mount等狀態對資料庫進行處理
所以通常要求sysdba許可權如果屬於本地DBA組，可以透過作業系統認證登陸
如果是遠端sysdba登陸，需要透過passwordfile認證.

1.remote_login_passwordfile = NONE

此時停用口令檔案驗證，Oracle資料庫不允許遠端SYSDBA/SYSOPER身份登入
無法透過遠端進行資料庫起停等操作管理

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

此處實際上是無法透過口令檔案驗證

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
已連線。
SQL> show user
USER 為"SYS"
SQL>

這實際上就是透過口令檔案驗證登入的

3.進一步測試

如果此時我們刪除passwdfile,sysdba/sysoper將無法認證，也就無法登陸資料庫

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>

這實際上就是無法透過口令檔案驗證身份

4.如果丟失了passwdfile

如果使用passwdfile卻意外丟失，此時將不能啟動資料庫

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

此時可以透過orapwd重建口令檔案來解決
此處我們恢復口令檔案既可

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

我們看一下Oracle9i文件中的說明:

SHARED

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

意思是說多個資料庫可以共享一個口令檔案,但是隻可以識別一個使用者: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

我們看到,此時的口令檔案中是不能新增使用者的.

很多人的疑問在於:口令檔案的預設名稱是orapw,怎麼能夠共享?

實際上是這樣的: Oracle資料庫在啟動時,首先查詢的是orapw的口令檔案,如果該檔案不存在,則開始查詢,orapw的口令檔案
如果口令檔案命名為orapw,多個資料庫就可以共享.

我們看一下測試:

[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'--這是最後查詢的檔案
ORA-27037: unable to obtain file status
Linux Error: 2: No such file or directory
Additional information: 3

我們建立orapw口令檔案,這時候可以開啟資料庫.

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>

那麼你可能會有這樣的疑問,多個Exclusive的資料庫是否可以共享一個口令檔案(orapw)呢?

我們繼續這個實驗:

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

注意這裡僅記錄著INTERNAL/SYS的口令

REMOTE_LOGIN_PASSWORDFILE=EXCLUSIVE 時

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

注意這裡,以EXCLUSIVE 方式啟動以後,例項名稱資訊被寫入口令檔案.

此時如果有其他例項以Exclusive模式啟動仍然可以使用這個口令檔案,口令檔案中的例項名稱同時被改寫.

也就是說,資料庫只在啟動過程中才讀取口令檔案,資料庫執行過程中並不鎖定該檔案,類似於pfile/spfile檔案.

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

注意此時可以增加SYSDBA使用者，並且這些資訊可以被寫入到口令檔案.

一旦口令檔案中增加了其他SYSDBA使用者,此檔案不再能夠被其他Exclusive的例項共享.

實際上，口令檔案對於其他使用者來說就是啟到了一個 sudo 的作用.

6.重建口令檔案

如果口令檔案丟失,可以使用orapwd可以重建口令檔案，語法如下:

[oracle@jumper oracle]$ orapwd
Usage: orapwd file= password= entries=

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.

(zt)Oracle中password file orapwd的作用及說明

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