本文共 2244 字，大约阅读时间需要 7 分钟。

Oracle????????????

1. ?????????( SCN )

????Oracle???????????????????????????????????????( SCN )?????????????????????????SCN??????SCN??????????????????????????

2. ??????

?????Control File??Oracle????????????????????????????????????????????????????????

• ????????????????system01.dbf??????????????/DBBK/oracle/oradata/orcl/?

• ??????????0?????8192??????????7??????????Dup=1??

• ?????????ID?0????????????0?

• SCN???SCN????????????????????scn: 0x0000.001d621a??2014-12-16 13:08:09?

3. ??????

?????Data File??Oracle??????????????????????????

• ????????????????system01.dbf?sysaux01.dbf?????????????/DBBK/oracle/oradata/orcl/?

• ??????????0?????8192??????????7??????????Dup=1??

• SCN????????SCN??????????????????scn: 0x0000.001d621a??2014-12-16 13:08:09?

4. ???????

??????????????????????????????

• ??1??2014-12-16 13:08:16????1????????SCN?0x0000.000e6c20?

• ??0??2014-12-16 13:08:40????0????????SCN?0x0000.000e6c20?

??????????????????????????????????????

5. ??????

?????Redo Log File????????????????????????????

• ????????????????redo01.log?redo02.log?redo03.log????redo???????/DBBK/oracle/oradata/orcl/?

• ???SCN?????????????SCN??????????1?2014-12-16 13:08:16?????SCN?0x0000.000e6c20?

• ????????????????????????????

6. ????

???????????

7. ??????

???????CheckPoint Cnt???????????????????

• CheckPoint cnt: 183 scn: 0x0000.001d6f61???2015-01-05 09:14:06??????183?????

• CheckPoint cnt: 182 scn: 0x0000.001d621a???2015-01-05 08:05:09??????182?????

8. ?????( SCN )

SCN????????????? SCN ??????

9. ????????

?????????????????????????????????

• ???????????restore_point_1?restore_point_2??

• ????????????????? SCN?

• ????????????????????????????

10. ?????

???????v$database?v$datafile_header?????????

• DBID: ???ID?1394247230?

• Checkpoint Change#: 2078903?

• Checkpoint Time: 2015-01-06 08:06:35?

?????????????????????????

11. ????

?????????????????

?????????????Oracle????????????????