如何在RAC环境下修改Oracle字符集

SQL> conn /as sysdba

SQL> shutdown immediate;

SQL> startup mount

SQL> ALTER SYSTEM ENABLE RESTRICTED SESSION;

SQL> ALTER SYSTEM SET JOB_QUEUE_PROCESSES=0;

SQL> ALTER SYSTEM SET AQ_TM_PROCESSES=0;

SQL> alter database open;

SQL> ALTER DATABASE character set INTERNAL_USE ZHS16GBK;

SQL> select from v$nls_parameters;

SQL> shutdown immediate;

SQL> startup

Database character set (AL32UTF8) and Client characterset (ZHS16GBK) are different

Character set conversion may cause unexpected results

Note: you can set the client character set through the NLS_LANG environmentvariable or the NLS_LANG registry key in

HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE\KEY_OraDb11g_home1

SIMPLIFIED CHINESE_CHINAZHS16GBK 包含 AMERICAN_AMERICAAL32UTF8

这可是个麻烦事，不是改客户端字符集的问题。要改数据库的字符集。我是自己笔记本上面的oracle11g，所以胆子还是很大的：

SQL> conn /as sysdba

SQL> shutdown immediate;

SQL> startup mount

SQL> ALTER SYSTEM ENABLE RESTRICTED SESSION;

SQL> ALTER SYSTEM SET JOB_QUEUE_PROCESSES=0;

SQL> ALTER SYSTEM SET AQ_TM_PROCESSES=0;

SQL> alter database open;

SQL> ALTER DATABASE CHARACTER SET ZHS16GBK;

ORA-12712: new character set must be a superset of old character set

提示我们的字符集：新字符集必须为旧字符集的超集，这时我们可以跳过超集的检查做更改：

SQL> ALTER DATABASE character set INTERNAL_USE ZHS16GBK;

--我们看到这个过程和之前ALTER DATABASE CHARACTER SET操作的内部过程是完全相同的，也就是说INTERNAL_USE提供的帮助就是使Oracle数据库绕过了子集与超集的校验

SQL> select from v$nls_parameters;

SQL> shutdown immediate;

SQL> startup

SQL> select from v$nls_parameters;

以后安装oracle11g的时候记得选择自定义安装，把这个字符集的事情事先弄好。

服务端修改字符集有点麻烦,要使客户端字符集与之一致,还有以前的dmp文件可能作废,

最好是修改client端的会话的字符集环境。

SQL>SHUTDOWN

IMMEDIATE;

SQL>STARTUP

MOUNT

EXCLUSIVE;

SQL>ALTER

SYSTEM

ENABLE

RESTRICTED

SESSION;

SQL>ALTER

SYSTEM

SET

JOB_QUEUE_PROCESSES=0;

SQL>ALTER

SYSTEM

SET

AQ_TM_PROCESSES=0;

SQL>ALTER

DATABASE

OPEN;

SQL>ALTER

DATABASE

NATIONAL

CHARACTER

SET

INTERNAL_USE

UTF8;

SQL>SHUTDOWN

immediate;

SQL>startup;