A、oracle server 端 字符集查询
select userenv(‘language’) from dual;
其中NLS_CHARACTERSET 为server端字符集
NLS_LANGUAGE 为 server端字符显示形式

B、查询oracle client端的字符集
$echo $NLS_LANG
如果发现你select 出来的数据是乱码，请把client端的字符集配置成与linux操作系统相同的字符集。如果还是有乱码，则有可能是数据库中的数据存在问题，或者是oracle服务端的配置存在问题。

C、server端字符集修改

*****************************************************************

*  更改字符集步骤方法(WE8ISO8859P1 --> ZHS16GBK)            *

***************************************************************** 

[oracle@datatest ~]$ sqlplus "/as sysdba"
 
SQL> conn /as sysdba
Connected.
SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup mount
ORACLE instance started.

Total System Global Area  236000356 bytes

Fixed Size                   451684 bytes

Variable Size             201326592 bytes

Database Buffers           33554432 bytes

Redo Buffers                 667648 bytes

Database mounted.

SQL> ALTER SYSTEM ENABLE RESTRICTED SESSION;

System altered.

SQL> ALTER SYSTEM SET JOB_QUEUE_PROCESSES=0;

System altered.

SQL> ALTER SYSTEM SET AQ_TM_PROCESSES=0;

System altered.

SQL> alter database open;

Database altered.

SQL> ALTER DATABASE CHARACTER SET ZHS16GBK;

ALTER DATABASE CHARACTER SET ZHS16GBK


ERROR at line 1:

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;

Database altered.

SQL> select * from v$nls_parameters;

略

19 rows selected.

重启检查是否更改完成：

SQL> shutdown immediate;

Database closed.

Database dismounted.

ORACLE instance shut down.

SQL> startup

ORACLE instance started.

Total System Global Area  236000356 bytes

Fixed Size                   451684 bytes

Variable Size             201326592 bytes

Database Buffers           33554432 bytes

Redo Buffers                 667648 bytes

Database mounted.

Database opened.

SQL> select userenv(‘language’) from dual;

USERENV('LANGUAGE')
--------------------------------------------------------------------------------
AMERICAN_AMERICA.ZHS16GBK

故障排除：

 

 

 

数据库成功开启！

 

SQL> shutdown immediate
ORA-01507: database not mounted

ORACLE instance shut down.
 
GOOGLE一下，发现是lk<SID>文件造成的，该文件位于ORALCE_HOME下的dbs目录下，马上检查该文件：
 
[root@qa-oracle dbs]# /sbin/fuser -u lkDATA   （DATA为数据库名）
lkDATA:             6666(oracle) 6668(oracle) 6670(oracle) 6672(oracle) 6674(oracle) 6676(oracle) 6678(oracle) 6680(oracle) 6690(oracle) 6692(oracle) 6694(oracle) 6696(oracle) 6737(oracle) 6830(oracle)
 
果然该文件没释放，用fuser命令kill掉：
[root@qa-oracle dbs]# /sbin/fuser -k lkDATA
lkDATA:             6666 6668 6670 6672 6674 6676 6678 6680 6690 6692 6694 6696 6737 6830
[root@qa-oracle dbs]# /sbin/fuser -u lkDATA
 
然后：
 
SQL> startup
ORACLE instance started.
Total System Global Area 276824064 bytes
Fixed Size                   778736 bytes
Variable Size             137371152 bytes
Database Buffers          138412032 bytes
Redo Buffers                 262144 bytes
Database mounted.
Database opened.
SQL>