Oracle Character set AL16UTF16 changed to ZHS16GBK

Al16utf16 a Kanji account of 3 bytes

ZHS16GBK a Kanji account of 2 bytes

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 to 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; Change international Character Set
===========
ALTER DATABASE CHARACTER SET ZHS16GBK; Change the local character set
Or
ALTER DATABASE Character Set Internal_use ZHS16GBK;
===========
SHUTDOWN IMMEDIATE;
STARTUP;

Oracle Character set AL16UTF16 changed to ZHS16GBK