Modify the character encoding of Oracle 10 GB

View Oracle character encoding:SQL>
Select * From nls_database_parameters;

Follow these steps:

SQL> shutdown immediate;/* shut down the database to re-mount and log on */

SQL> startup Mount;
SQL> alter system enable restricted session;
SQL> alter system set job_queue_processes = 0;
SQL> alter database open;
SQL> alter database character set internal_useUtf8;
SQL> shutdown immediate;
SQL> startup
Note: the character set must be supported by Oracle. Otherwise, you cannot start up.