如何快速找到备份过最近、最大序号的归档日志

« Oracle EXP/IMP与临时对象的管理方式 | Blog首页 | 惊天动地盖小咪 - 记第一次受伤 »

最近客户有这样一个需求，由于备份时是不删除归档的，所以会导致积累了大量的归档日志存储。
当手工清除时，我们需要找到那个备份过的最近的归档日志，直接列举会有常常的一个列表，并且备份集展示是无序的。

在RAC环境中，连续的归档日志也可能分布到不同的备份集.

我们常用列举备份过的归档日志的命令是：
list backup of archivelog all;

这里我们可以用另外一个命令：
LIST BACKUP OF ARCHIVELOG FROM SEQUENCE seq_no [THREAD thread_no];
选择一个合适的SEQuence号，接下来这个命令会将备份过的日志按照序号展现出来，非常便于观察。
对于RAC环境不同的Thread可以加上不同的Thread号。

对于单节点数据库是这样的

RMAN> LIST BACKUP OF ARCHIVELOG FROM SEQUENCE 5555;

List of Backup Sets
===================

BS Key Size Device Type Elapsed Time Completion Time
------- ---------- ----------- ------------ ---------------
1281 2.44G DISK 00:00:54 23-APR-09
BP Key: 1281 Status: AVAILABLE Compressed: NO Tag: TAG20090423T045004
Piece Name: /rman_backup/archivelog/archive_MDB_1281_1_1

List of Archived Logs in backup set 1281
Thrd Seq Low SCN Low Time Next SCN Next Time
---- ------- ---------- --------- ---------- ---------
1 5555 4810229702 23-APR-09 4810242319 23-APR-09
1 5556 4810242319 23-APR-09 4810253268 23-APR-09
1 5557 4810253268 23-APR-09 4810266091 23-APR-09
1 5558 4810266091 23-APR-09 4810277402 23-APR-09
1 5559 4810277402 23-APR-09 4810288629 23-APR-09
1 5560 4810288629 23-APR-09 4810301159 23-APR-09
1 5561 4810301159 23-APR-09 4810313380 23-APR-09
1 5562 4810313380 23-APR-09 4810325917 23-APR-09
1 5563 4810325917 23-APR-09 4810338897 23-APR-09
1 5564 4810338897 23-APR-09 4810352419 23-APR-09

RMAN> LIST BACKUP OF ARCHIVELOG FROM SEQUENCE 5562;

List of Backup Sets
===================

BS Key Size Device Type Elapsed Time Completion Time
------- ---------- ----------- ------------ ---------------
1281 2.44G DISK 00:00:54 23-APR-09
BP Key: 1281 Status: AVAILABLE Compressed: NO Tag: TAG20090423T045004
Piece Name: /rman_backup/archivelog/archive_MDB_1281_1_1

List of Archived Logs in backup set 1281
Thrd Seq Low SCN Low Time Next SCN Next Time
---- ------- ---------- --------- ---------- ---------
1 5562 4810313380 23-APR-09 4810325917 23-APR-09
1 5563 4810325917 23-APR-09 4810338897 23-APR-09
1 5564 4810338897 23-APR-09 4810352419 23-APR-09

对于集群环境，可以如下：

RMAN> list backup of archivelog from sequence 4650 thread 2;

List of Backup Sets
===================

BS Key Size Device Type Elapsed Time Completion Time
------- ---------- ----------- ------------ ---------------
1502 1.34G DISK 00:00:17 23-APR-09
BP Key: 1502 Status: AVAILABLE Compressed: NO Tag: TAG20090423T045014
Piece Name: /data/rman_backup/archivelog/archive_SDB_1505_1_1

List of Archived Logs in backup set 1502
Thrd Seq Low SCN Low Time Next SCN Next Time
---- ------- ---------- --------- ---------- ---------
2 4650 5935657272 22-APR-09 5936032418 22-APR-09
2 4651 5936032418 22-APR-09 5936324099 23-APR-09
2 4652 5936324099 23-APR-09 5936595419 23-APR-09
2 4653 5936595419 23-APR-09 5936606454 23-APR-09

RMAN> list backup of archivelog from sequence 6266 thread 1;

List of Backup Sets
===================

BS Key Size Device Type Elapsed Time Completion Time
------- ---------- ----------- ------------ ---------------
1502 1.34G DISK 00:00:17 23-APR-09
BP Key: 1502 Status: AVAILABLE Compressed: NO Tag: TAG20090423T045014
Piece Name: /data/rman_backup/archivelog/archive_SDB_1505_1_1

List of Archived Logs in backup set 1502
Thrd Seq Low SCN Low Time Next SCN Next Time
---- ------- ---------- --------- ---------- ---------
1 6266 5936066418 22-APR-09 5936180981 23-APR-09
1 6267 5936180981 23-APR-09 5936324084 23-APR-09
1 6268 5936324084 23-APR-09 5936413698 23-APR-09
1 6269 5936413698 23-APR-09 5936462250 23-APR-09
1 6270 5936462250 23-APR-09 5936595368 23-APR-09
1 6271 5936595368 23-APR-09 5936606456 23-APR-09