?????????SCN??System Change Number ??? SCN?????Oracle????????o???DBMS????????????????????????????????ORACLE??????????????ORACLE 10G???????????????????SCN???????????????
????????????????????????????????????????????????SCN????????????????????
??????????????
????1?????dbms_flashback.get_system_change_number??????????SCN???
????SQL>  select dbms_flashback.get_system_change_number scn from dual;
????SCN
????-----------------
????122037263
????2?????scn_to_timestamp?????????SCN????????:SQL> select scn_to_timestamp(122037263) scn from dual;
????SCN
????---------------------------------------------------------------------------
????14-7?? -14 04.45.36.000000000 ????
????3???????????timestamp_to_scn?????????????SCN:
????SQL> select timestamp_to_scn(to_date('2014-07-13??13:25:59'??'yyyy-mm-dd??hh24:mi:ss')) scn from dual;
????SCN
????---------------------
????121936647