AL16UTF16一个汉字占3个字节
ZHS16GBK一个汉字占2个字节
sql> conn / as sysdba;
sql> shutdown immediate;
database closed.
database dismounted.
oracle instance shut down.
sql> startup mount;
oracle instance started.
total system global area 135337420 bytes
fixed size 452044 bytes
variable size 109051904 bytes
database buffers 25165824 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 internal_use UTF-8;
sql> shutdown immediate;
sql> startup;
------------------------
10g：UTF8 到ZHS16GBK
SHUTDOWN IMMEDIATE;
STARTUP MOUNT ;
ALTER SYSTEM ENABLE RESTRICTED SESSION;
ALTER SYSTEM SET JOB_QUEUE_PROCESSES=0;
ALTER SYSTEM SET AQ_TM_PROCESSES=0;
ALTER DATABASE OPEN;
ALTER DATABASE NATIONAL CHARACTER SET AL16UTF16; 更改国际字符集
===========
ALTER DATABASE CHARACTER SET ZHS16GBK; 更改本地字符集
或者
ALTER DATABASE character set INTERNAL_USE ZHS16GBK;
===========
SHUTDOWN IMMEDIATE;
STARTUP ;