[sql]

SQL> select sequence#,first_change#,next_change# from v$archived_log

2 where sequence#>=11;

SEQUENCE# FIRST_CHANGE# NEXT_CHANGE#

---------- ------------- ------------

11 583374 586090

12 586090 586181

13 586181 586656

14 586656 586676

15 586676 586704

16 586704 586734

17 586734 586762

18 586762 586816

从上面可知，如果我们想把数据全部找回，我们需要借助到归档日志18.我们看一下这些first_change#和next_change#有什么特色？

归档日志11的next_change#是归档日志12的first_change#。以此类推，所以，这么多的归档日志，其实，逻辑上就只是一个归档日志。因此，归档日志必须连续！如果，你归档日志13坏了，那么只能恢复到12的next_change#。后面再多的归档也是徒然。

接下来，我们开始恢复。 www.2cto.com

[sql]

SQL> recover datafile 1;

ORA-00279: change 583375 generated at 07/17/2012 19:59:23 needed for thread 1

ORA-00289: suggestion :

/u01/app/oracle/flash_recovery_area/ORCL/archivelog/2012_07_18/o1_mf_1_11_%u_.ar

c

ORA-00280: change 583375 for thread 1 is in sequence #11

Specify log: {=suggested | filename | AUTO | CANCEL}

oracle告诉我们，583375 对于实例是需要的。并且，归档日志11在闪回区。如果敲回车，则采纳oracle的建议，oracle会自己到闪回区里面去找。我们敲一下回车键采纳oracle的建议。第二个选项，是不在默认路径里面，由你来告诉oracle，归档日志身在何处。你只要告诉oracle，归档日志的绝对路径+名称，就可以了。第三个选项，如果归档日志很多，一个个挨着去找，显得很麻烦，那么我们就去auto。第四个选项，如果恢复到一半，或者，没有了归档日志，那么你可以敲cancel。

[sql]

ORA-00279: change 586090 generated at 07/18/2012 09:35:40 needed for thread 1

ORA-00289: suggestion :

/u01/app/oracle/flash_recovery_area/ORCL/archivelog/2012_07_18/o1_mf_1_12_%u_.ar

c

ORA-00280: change 586090 for thread 1 is in sequence #12

ORA-00278: log file

'/u01/app/oracle/flash_recovery_area/ORCL/archivelog/2012_07_18/o1_mf_1_11_80d4q

dmh_.arc' no longer needed for this recovery

Specify log: {=suggested | filename | AUTO | CANCEL}

这时，oracle会再告诉我们，日志12是实例所需要的。我们先把这事给搁着。先去数据文件文件头，把scn给取出来瞧瞧。

[sql]

SQL> select file#,checkpoint_change# from v$datafile_header;

FILE# CHECKPOINT_CHANGE#

---------- ------------------

1 586090

2 0

3 0

4 0

5 587004

发现没？file 1 的scn变成了586090。而586090是归档日志12的first_change#。难怪oracle告诉我们日志12是实例必须的。接下来，我们敲auto。

[sql]

Specify log: {=suggested | filename | AUTO | CANCEL}

auto

ORA-00279: change 586181 generated at 07/18/2012 09:39:21 needed for thread 1

ORA-00289: suggestion :

/u01/app/oracle/flash_recovery_area/ORCL/archivelog/2012_07_18/o1_mf_1_13_%u_.ar

c

ORA-00280: change 586181 for thread 1 is in sequence #13

ORA-00278: log file

'/u01/app/oracle/flash_recovery_area/ORCL/archivelog/2012_07_18/o1_mf_1_12_80d4y

9fp_.arc' no longer needed for this recovery

ORA-00279: change 586656 generated at 07/18/2012 09:42:06 needed for thread 1

ORA-00289: suggestion :

/u01/app/oracle/flash_recovery_area/ORCL/archivelog/2012_07_18/o1_mf_1_14_%u_.ar

c

ORA-00280: change 586656 for thread 1 is in sequence #14

ORA-00278: log file

'/u01/app/oracle/flash_recovery_area/ORCL/archivelog/2012_07_18/o1_mf_1_13_80d53

g42_.arc' no longer needed for this recovery