SQL> SHUTDOWN IMMEDIATE;
SQL> STARTUP MOUNT;
SQL> ALTER SYSTEM ENABLE RESTRICED SESSION;
SQL> ALTER SYSTEM SET JOB_QUEUE_PROCESSES=0;
SQL> ALTER DATABASE OPEN;
SQL> ALTER DATABASE CHARACTER SET <new_character_set_name>;
SQL> SHUTDOWN IMMEDIATE;
SQL> STARTUP;
insert into tw_shengfen@linktooa select shengfen from tw_shengfen:不行
insert into tw_shengfen@linktooa select convert(shengfen,'ZHS16GBK') from tw_shengfen :也不行