How to modify the character set of Oracle 9i to utf8 (Chinese)

1. If Oracle 9i is installed, the default value in the National charset is al16utf16.
If you want to change al16utf16 to utf8
Follow the previous method
Update SYS. Props $
Set Value $ = 'utf8' where name = ''nls _ nchar_characterset '';
The charset information is not fully reflected in Oracle.
Therefore, when inserting data in a table, the value is set to al16utf16, and only the default space is set to utf8 ..

2, so we should change it like this
$ Sqlplus '/As sysdba'
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 utf8;
SQL> shutdown immediate;
SQL> startup;

You can use the preceding method, but 'ora-12717: cannot alter database national character set when may appear.
Message like nclob data exists

There are two ways to solve this problem

One is to use the internal_use keyword to modify the region settings, and the other is to use re-create, but re-create is a bit complicated, so use internal_use,
$ Sqlplus '/As sysdba'
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 immed

If you follow the above steps, the National charset region settings will be fine.