Character Set modification and exceptions in oracle 10 Gb Database

Oracle 10g Database Character Set Change and exceptions 1. change the DATABASE character SET to gbkshutdown immediate; startup mount exclusive; alter system enable restricted session; alter system set JOB_QUEUE_PROCESSES = 0; alter system set AQ_TM_PROCESSES = 0; alter database open; alter database national character set AL16UTF16; alter database character set ZHS16GBK; change local character set shutdown immediate; STARTUP; -- alter database national character set INTERNAL_USE UTF8; -- alter database character set internal_use ZHS16GBK; -- alter database national character set INTERNAL_USE ZHS16GBK; 2. if the error message is returned, compare the information with the following statement if the prompt is: ORA-12717: Cannot issue alter database national character set when NCLOB, NCHAR or NVARCHAR2 data exists: alter database national character set INTERNAL_USE AL16UTF16; use the following statement if the prompt is: ORA-12712: new character set must be a superset of old character set: alter database character set INTERNAL_USE ZHS16GBK; if prompted: ORA-12721: operation cannot execute when other sessions are active, change using the following statement: shutdown immediate; startup mount exclusive; if prompted: ORA-01109: database not open, change using the following statement: alter database open; if the prompt is: ORA-12719: operation requires database is in RESTRICTED mode, change using the following statement: alter system enable restricted session;