new character set must be a superset of old character set

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

In Oracle Database 10g you can get this error.

For solve this error you can use

ALTER DATABASE CHARACTER SET INTERNAL_USE AL32UTF8;

SQL> ALTER DATABASE CHARACTER SET AL32UTF8;
ALTER DATABASE CHARACTER SET AL32UTF8
*
ERROR at line 1:
ORA-12712: new character set must be a superset of old character set


SQL> ALTER DATABASE CHARACTER SET INTERNAL_USE AL32UTF8;

Database altered.

All steps for change database character parameter.

SQL> SHUTDOWN IMMEDIATE;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> STARTUP RESTRICT;
ORACLE instance started.

Total System Global Area  612368384 bytes
Fixed Size                  1292036 bytes
Variable Size             268437756 bytes
Database Buffers          335544320 bytes
Redo Buffers                7094272 bytes
Database mounted.
Database opened.
SQL> ALTER SYSTEM SET JOB_QUEUE_PROCESSES=0;

System altered.

SQL> ALTER SYSTEM SET AQ_TM_PROCESSES=0;

System altered.

SQL>
SQL>
SQL> ALTER DATABASE CHARACTER SET AL32UTF8;
ALTER DATABASE CHARACTER SET AL32UTF8
*
ERROR at line 1:
ORA-12712: new character set must be a superset of old character set


SQL> ALTER DATABASE CHARACTER SET INTERNAL_USE AL32UTF8;

Database altered.

SQL> SHUTDOWN IMMEDIATE;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> STARTUP;
ORACLE instance started.

Total System Global Area  612368384 bytes
Fixed Size                  1292036 bytes
Variable Size             272632060 bytes
Database Buffers          331350016 bytes
Redo Buffers                7094272 bytes
Database mounted.
Database opened.