$ isqlplusctl stop
$ emctl stop dbconsole
$ lsnrctl stop
$ sqlplus /nolog
SQL> conn sys / as sysdba
SQL> shutdown immediate
SQL> startup nomount
SQL> alter database 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 character set internal_use zhs16gbk;
SQL> shutdown immediate
SQL> startup nomount
SQL> alter database mount exclusive;
SQL> alter system disable restricted session;
SQL> alter database open;
SQL> exit
$ lsnrctl start
$ emctl start dbconsole
$ isqlplusctl start