oracle password file issue

There is a online help from a old fellow which it’s oracle RAC env meet the error root in corrupt of orapwd file.This kind of issue can be fixed by following guide:

source from:http://www.adp-gmbh.ch/ora/admin/password_file.html

Oracle’s password file

If the DBA wants to start up an Oracle instance there must be a way for Oracle to authenticate this DBA. That is if (s)he is allowed to do so. Obviously, his password can not be stored in the database, because Oracle can not access the database before the instance is started up. Therefore, the authentication of the DBA must happen outside of the database. There are two distinct mechanisms to authenticate the DBA: using the password file or through the operating system.
The init parameter remote_login_passwordfile specifies if a password file is used to authenticate the DBA or not. If it set either to shared or exclusive a password file will be used.
Default location and file name
The default location for the password file is: $ORACLE_HOME/dbs/orapw$ORACLE_SID on Unix and %ORACLE_HOME%\database\PWD%ORACLE_SID%.ora on Windows.
Deleting a password file
If password file authentication is no longer needed, the password file can be deleted and the init parameter remote_login_passwordfile set to none.
Password file state
If a password file is shared or exclusive is also stored in the password file. After its creation, the state is shared. The state can be changed by setting remote_login_passwordfile and starting the database. That is, the database overwrites the state in the password file when it is started up.
A password file whose state is shared can only contain SYS.
Creating a password file
Password files are created with the orapwd tool.
Adding Users to the password file
Users are added to the password file when they’re granted the SYSDBA or sysoper privilege.

SYS@ora10> show user;
USER is "SYS"
SYS@ora10> select * from v$pwfile_users;

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

SYS@ora10> grant SYSDBA to rene;

Grant succeeded.

SYS@ora10> select * from v$pwfile_users;

USERNAME                       SYSDB SYSOP
------------------------------ ----- -----
SYS                            TRUE  TRUE
RENE                           TRUE  FALSE

SYS@ora10> grant SYSOPER to rene;

Grant succeeded.

SYS@ora10> select * from v$pwfile_users;

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

SYS@ora10> revoke SYSDBA from rene;

Revoke succeeded.

SYS@ora10> select * from v$pwfile_users;

USERNAME                       SYSDB SYSOP
------------------------------ ----- -----
SYS                            TRUE  TRUE
RENE                           FALSE TRUE

SYS@ora10> revoke SYSOPER from rene;

Revoke succeeded.

SYS@ora10> select * from v$pwfile_users;

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

–EOF–

Firewall、DCD、TCP Keep alive

from :http://blogread.cn/it/article/5198?f=wb

在以前我写的一篇文章《Oracle与防火墙》中提到,网络防火墙会切断长时间空闲的TCP连接,这个空闲时间具体多长可以在防火墙内部进行设置。防火墙切断连接之后,会有下面的可能:

 

  • 切断连接之前,连接对应的Oracle会话正在执行一个耗时特别长的SQL,比如存储过程而在此过程中没有任何数据输出到客户端,这样当SQL执行完成之后,向客户端返回结果时,如果TCP连接已经被防火墙中断,这时候显然会出现错误,连接中断,那么会话也就会中断。但是客户端还不知道,会一直处于等待服务器返回结果的状态。

 

从上面的前面2种情况来看,防火墙切断数据库TCP连接,引起的后果就会有: Continue reading “Firewall、DCD、TCP Keep alive”