SQL>select userenv('language') from dual;
SQL> shutdown immediate;
SQL> startup mountSQL> 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 CHARACTER SET ZHS16GBK;
ORA-12712: new character set must be a superset of old character set
提示我们的字符集:新字符集必须为旧字符集的超集,这时我们可以跳过超集的检查做更改:
SQL> ALTER DATABASE character set INTERNAL_USE ZHS16GBK;
--我们看到这个过程和之前ALTER DATABASE CHARACTER SET操作的内部过程是完全相同的,也就是说INTERNAL_USE提供的帮助就是使Oracle数据库绕过了子集与超集的校验.
SQL> shutdown immediate;
SQL> startup
SQL>select userenv('language') from dual;