如何正确地删除Archivelog:
Archivelog并不能直接得从OS层直接物理删除,因为archivelog的相关信息是记录在controlfile中的,当物理删除后不会改变controlfile的设置。并且在查询相关的动态视图(例如v$archived_log)时,该部分日志仍然标注为存在。也就是说Oracle并不认为这些日志被删除了,所以在删除archivelog的时候,需要我们在其他地方做一些设置。


一、使用RMAN清楚物理删除后的记录
可以使用RMAN来删除archivelog,具体可以按以下步骤操作:
1、物理删除archivelog
2、进入RMAN
3、crosscheck archivelog all;
4、delete expiredarchivelog all;
这样就在一些Oracle的记录中查不到相应的archivelog记录了。


二、直接使用RMAN删除archivelog
其实在RMAN中是可以使用命令直接将ARCHIVELOG删除的,命令如下:
RMAN> DELETE ARCHIVELOG ALL COMPLETED BEFORE 'SYSDATE-7';
表示删除7天以前的所有archivelog,但是这个命令的缺点是无法对archivelog进行细致的划分。


三、使用RMAN备份achivelog后删除
这是一种最为稳妥的方法了,使用RMAN备份archivelog,备份后全部删除
backup format '/u01/arch_%T_%s_%U' archivelog all delete input;
或者
backup database plus archivelog;


注:我在库上设置了Streams后,使用RMAN删除archivelog会导致报错RMAN-08137: WARNING:
archive log not deleted as it is still needed. 不知道该如何解决,据说是10.2的一个bug,如果真
是bug的话,那只能在OS层设置删除,或用RMAN进行强制删除了。
10g之后的版本,Oracle在RMAN中内置增加了一项归档文件的删除策略,终于,DBA可以仅通过一项配置就
解决该问题了。该策略对应两个值:
APPLIED ON STANDBY:设置为该值时,当通过附加的DELETE INPUT子句删除Standby数据库仍需要的日志
时,会提示RMAN-08137错误。不过用户仍然可以手动地通过DELETE ARCHIVELOG方式删除。
NONE:设置为该值时,则不启用归档文件的删除策略。默认情况下就是NONE。
例如,启用APPLIED ON STANDBY:

RMAN> CONFIGURE ARCHIVELOG DELETION POLICY TO APPLIED ON STANDBY;
 new RMAN configuration parameters:
 CONFIGURE ARCHIVELOG DELETION POLICY TO APPLIED ON STANDBY;
 new RMAN configuration parameters are successfully stored
 RMAN> run
 {
 backup archivelog all delete input format 'ZHSVR044_%d_set=%s_piece=%p_date=%T.ARC.rmn';
 }



都知道在controlfile中记录着每一个archivelog的相关信息,当然们在OS下把这些物理文件delete掉后,在我们的
controlfile中仍然记录着这些archivelog的信息,在oracle的OEM管理器中有可视化的日志展现出,当我们手工清除archive目录下的文件后,这些记录并没有被我们从controlfile中清除掉,也就是oracle并不知道这些文件已经不存在了!这时候我们要做手工的清除的话,下面我经过实验,可以尝试这种方法:
1. 进入rman
2. connect target /
3. crosscheck archivelog all;
4. delete expired archivelog all;
这时候我们再去OEM中看就一定看不到,如果你的从来没有做过这个动作的话,我们可以比较从这个动作前的controlfile后动作后的controlfile的大小!


ORACLE正确删除归档并回收空间的方法
ORACLE正确删除归档并回收空间的方法
一个ORACLE归档日志经常满,表现为/oraarchive 这个文件空间占用100%大家一定抱怨ORACLE为何没有归档维护工具,很多人直接删除了事,错了,ORACLE有,而且很智能,可以正确的删除归档和FLASHBACK,不过切记,ORACLE归档日志对于ORACLE的数据恢复和备份非常重要,不到万不得已不要删除归档日志。
删除归档日志的过程
以ORACLE用户身份登录到数据库服务器主机或通过网络连接
进入ORACLE数据备份工具
rman target/
或rman target/@orcl
在命令窗口里面执行
DELETE ARCHIVELOG ALL COMPLETED BEFORE 'SYSDATE-7';
说明
SYSDATA-7,表明当前的系统时间7天前,before关键字表示在7天前的归档日志,如果使用了闪回功能,也会删除闪回的数据。
同样道理,也可以删除从7天前到现在的全部日志,不过这个命令要考虑清楚,做完这个删除,最好马上进行全备份数据库
DELETE ARCHIVELOG FROM TIME 'SYSDATE-7';


UNIX/LINUX下也可以通过FIND找到7天前的归档数据,使用EXEC子操作删除

find /oraarchive -xdev -mtime +7 -name "*.dbf" -exec rm -f {} ;
 这样做仍然会在RMAN里留下未管理的归档文件
 仍需要在RMAN里执行下面2条命令
 crosscheck archivelog all;
 delete expired archivelog all;
 所以还不如上面的方法好用,不过用FIND的好处就是,可以在条件上,和EXEC子项上做很多操作,实现更复杂的功能
 3.简要介绍一下report obsolete命令
 使用report obsolete命令报告过期备份
 RMAN> report obsolete;
 RMAN retention policy will be applied to the command
 RMAN retention policy is set to redundancy 1
 Report of obsolete backups and copies
 Type Key Completion Time Filename/Handle
 -------------------- ------ ------------------ --------------------
 Backup Set 125 01-NOV-04
 Backup Piece 125 01-NOV-04 /data1/oracle/orabak/full_1_541045804
 Backup Set 131 04-NOV-04
 Backup Piece 131 04-NOV-04 /data1/oracle/orabak/full_AVATAR2_20041104_131
 ....
 Backup Set 173 06-DEC-04
 Backup Piece 173 06-DEC-04 /data1/oracle/orabak/full_AVATAR2_20041206_173
 Backup Set 179 11-DEC-04
 Backup Piece 179 11-DEC-04 /data1/oracle/orabak/arch544588206.arc
 .....
 Backup Piece 189 17-DEC-04 /data1/oracle/orabak/arch545106606.arc
 Backup Set 190 17-DEC-04
 Backup Piece 190 17-DEC-04 /data1/oracle/orabak/arch545106665.arc
 Backup Set 191 20-DEC-04
 Backup Piece 191 20-DEC-04 /data1/oracle/orabak/arch_AVATAR2_20041220_194
 Archive Log 2973 20-DEC-04 /opt/oracle/oradata/avatar2/archive/1_2985.dbf
 Archive Log 2971 20-DEC-04 /opt/oracle/oradata/avatar2/archive/1_2984.dbf
 .....
 Archive Log 2705 17-DEC-04 /opt/oracle/oradata/avatar2/archive/1_2717.dbf
 Archive Log 2704 17-DEC-04 /opt/oracle/oradata/avatar2/archive/1_2716.dbf
 Archive Log 2703 17-DEC-04 /opt/oracle/oradata/avatar2/archive/1_2715.dbf
 Archive Log 2702 17-DEC-04 /opt/oracle/oradata/avatar2/archive/1_2714.dbf
 4.使用delete obsolete命令删除过期备份:
 RMAN> delete obsolete;
 RMAN retention policy will be applied to the command
 RMAN retention policy is set to redundancy 1
 using channel ORA_DISK_1
 Deleting the following obsolete backups and copies:
 Type Key Completion Time Filename/Handle
 -------------------- ------ ------------------ --------------------
 Backup Set 125 01-NOV-04
 Backup Piece 125 01-NOV-04 /data1/oracle/orabak/full_1_541045804
 ....
 Archive Log 2704 17-DEC-04 /opt/oracle/oradata/avatar2/archive/1_2716.dbf
 Archive Log 2703 17-DEC-04 /opt/oracle/oradata/avatar2/archive/1_2715.dbf
 Archive Log 2702 17-DEC-04 /opt/oracle/oradata/avatar2/archive/1_2714.dbf
 Do you really want to delete the above objects (enter YES or NO)? yes
 deleted backup piece
 backup piece handle=/data1/oracle/orabak/full_AVATAR2_20041206_173 recid=173 stamp=544156241
 .....
 deleted archive log
 archive log filename=/opt/oracle/oradata/avatar2/archive/1_2715.dbf recid=2703 stamp=545108268
 deleted archive log
 archive log filename=/opt/oracle/oradata/avatar2/archive/1_2714.dbf recid=2702 stamp=545107659
 Deleted 286 objects


 RMAN> crosscheck archivelog all;
 released channel: ORA_DISK_1
 allocated channel: ORA_DISK_1
 channel ORA_DISK_1: sid=19 devtype=DISK
 specification does not match any archive log in the recovery catalog


5 在rman中用crosscheck检查归档日志,2个归档日志都是失败的:
RMAN> crosscheck archivelog all;
释放的通道: ORA_DISK_1
分配的通道: ORA_DISK_1
通道 ORA_DISK_1: sid=14 devtype=DISK
对归档日志的验证失败
存档日志文件名 =D:ORACLEORADATATESTARCHIVE1_47.DBF 记录 ID=1 时间戳 =572866
683
对归档日志的验证失败
存档日志文件名 =D:ORACLEORADATATESTARCHIVE11_48.DBF 记录 ID=2 时间戳 =57286
6931
已交叉检验的 2 对象
6 试着同步一下,看行不行,结果不行,crosscheck还是失败:

RMAN> resync catalog;
 正在启动全部恢复目录的 resync
 完成全部 resync
 RMAN> crosscheck archivelog all;
 释放的通道: ORA_DISK_1
 分配的通道: ORA_DISK_1
 通道 ORA_DISK_1: sid=14 devtype=DISK
 对归档日志的验证失败
 存档日志文件名 =D:ORACLEORADATATESTARCHIVE1_47.DBF 记录 ID=1 时间戳 =572866
 683
 对归档日志的验证失败
 存档日志文件名 =D:ORACLEORADATATESTARCHIVE11_48.DBF 记录 ID=2 时间戳 =57286
 6931
 已交叉检验的 2 对象
 7 用list expired看看是否有失效的archive log,证明没有失效的archive log:
 RMAN> list expired archivelog all;
 说明与恢复目录中的任何存档日志均不匹配
 8 更改语言环境试试,结果再次crosscheck,2个archive log 都成功了:
 RMAN> exit


 恢复管理器完成。
 C:>set nls_lang=american_america.zhs16gbk
 C:>rman catalogrman/rman@safetarget /
 Recovery Manager: Release 9.2.0.1.0 - Production
 Copyright (c) 1995, 2002, Oracle Corporation. All rights reserved.
 connected to target database: TEST (DBID=1870953724)
 connected to recovery catalog database
 RMAN> crosscheck archivelog all;
 allocated channel: ORA_DISK_1
 channel ORA_DISK_1: sid=9 devtype=DISK
 validation succeeded for archived log
 archive log filename=D:ORACLEORADATATESTARCHIVE1_47.DBF recid=1 stamp=57286
 6683
 validation succeeded for archived log
 archive log filename=D:ORACLEORADATATESTARCHIVE11_48.DBF recid=2 stamp=5728
 66931
 Crosschecked 2 objects


 删除N天以前的归档日志,有两个命令:
 delete archivelog until time 'sysdate-N'
 delete archivelog all completed before 'sysdate-N'

 看下两者的区别:
 RMAN> list archivelog until time 'sysdate-1';
 List of Archived Log Copies
 Key Thrd Seq S Low Time Name
 ------- ---- ------- - ---------- ----
 7 1 5 A 13-7月 -11 +RECOVERY/edu/archivelog/2011_07_13/thread_1_seq_5.259.756405771
 10 1 6 A 13-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_1_seq_6.263.756453607
 16 1 7 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_1_seq_7.268.756467343
 17 1 8 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_1_seq_8.269.756467345
 18 1 9 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_1_seq_9.270.756467399
 19 1 10 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_1_seq_10.271.756467403
 21 1 11 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_1_seq_11.272.756467511
 22 1 12 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_1_seq_12.274.756467515
 23 1 13 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_1_seq_13.275.756467521
 25 1 14 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_1_seq_14.276.756467527
 26 1 15 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_1_seq_15.278.756467635
 27 1 16 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_1_seq_16.279.756484801
 29 1 17 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_15/thread_1_seq_17.256.756576859
 5 2 2 A 13-7月 -11 +RECOVERY/edu/archivelog/2011_07_13/thread_2_seq_2.257.756405175
 8 2 3 A 13-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_2_seq_3.260.756442807
 9 2 4 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_2_seq_4.261.756442823
 11 2 5 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_2_seq_5.262.756453607
 12 2 6 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_2_seq_6.264.756453623
 13 2 7 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_2_seq_7.265.756467273
 14 2 8 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_2_seq_8.266.756467279
 15 2 9 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_2_seq_9.267.756467279
 20 2 10 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_2_seq_10.273.756467511
 24 2 11 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_2_seq_11.277.756467533
 28 2 12 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_15/thread_2_seq_12.280.756566433
 最大sequence为17和12
 再看:
 RMAN> list archivelog all completed before 'sysdate-1';


 List of Archived Log Copies
 Key Thrd Seq S Low Time Name
 ------- ---- ------- - ---------- ----
 7 1 5 A 13-7月 -11 +RECOVERY/edu/archivelog/2011_07_13/thread_1_seq_5.259.756405771
 10 1 6 A 13-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_1_seq_6.263.756453607
 16 1 7 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_1_seq_7.268.756467343
 17 1 8 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_1_seq_8.269.756467345
 18 1 9 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_1_seq_9.270.756467399
 19 1 10 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_1_seq_10.271.756467403
 21 1 11 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_1_seq_11.272.756467511
 22 1 12 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_1_seq_12.274.756467515
 23 1 13 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_1_seq_13.275.756467521
 25 1 14 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_1_seq_14.276.756467527
 26 1 15 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_1_seq_15.278.756467635
 27 1 16 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_1_seq_16.279.756484801
 5 2 2 A 13-7月 -11 +RECOVERY/edu/archivelog/2011_07_13/thread_2_seq_2.257.756405175
 8 2 3 A 13-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_2_seq_3.260.756442807
 9 2 4 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_2_seq_4.261.756442823
 11 2 5 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_2_seq_5.262.756453607
 12 2 6 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_2_seq_6.264.756453623
 13 2 7 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_2_seq_7.265.756467273
 14 2 8 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_2_seq_8.266.756467279
 15 2 9 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_2_seq_9.267.756467279
 20 2 10 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_2_seq_10.273.756467511
 24 2 11 A 14-7月 -11 +RECOVERY/edu/archivelog/2011_07_14/thread_2_seq_11.277.756467533

 详细看下 这些日志的区别:
 QL> select THREAD#,sequence#,FIRST_TIME,NEXT_TIME,COMPLETION_TIME 
 2 from v$archived_log order by thread#,sequence#;
 THREAD# SEQUENCE# FIRST_TIME NEXT_TIME COMPLETION_TIME
 ---------- ---------- ----------------- ----------------- -----------------
 1 1 20110713 14:57:58 20110713 14:58:42 20110713 14:58:49
 1 2 20110713 14:58:42 20110713 14:59:00 20110713 14:59:18
 1 3 20110713 14:59:00 20110713 15:02:31 20110713 15:02:36
 1 4 20110713 15:02:31 20110713 16:32:50 20110713 16:32:57
 1 5 20110713 16:32:50 20110713 16:41:40 20110713 16:42:51
 1 6 20110713 16:41:40 20110714 06:00:07 20110714 06:00:08
 1 7 20110714 06:00:07 20110714 09:26:57 20110714 09:49:04
 1 8 20110714 09:26:57 20110714 09:46:55 20110714 09:49:04
 1 9 20110714 09:46:55 20110714 09:49:58 20110714 09:50:06
 1 10 20110714 09:49:58 20110714 09:50:02 20110714 09:50:09
 1 11 20110714 09:50:02 20110714 09:51:49 20110714 09:51:59
 THREAD# SEQUENCE# FIRST_TIME NEXT_TIME COMPLETION_TIME
 ---------- ---------- ----------------- ----------------- -----------------
 1 12 20110714 09:51:49 20110714 09:51:55 20110714 09:52:05
 1 13 20110714 09:51:55 20110714 09:52:01 20110714 09:52:10
 1 14 20110714 09:52:01 20110714 09:52:07 20110714 09:52:13
 1 15 20110714 09:52:07 20110714 09:53:54 20110714 09:53:59
 1 16 20110714 09:53:54 20110714 14:40:01 20110714 14:40:05
 1 17 20110714 14:40:01 20110715 16:14:19 20110715 16:14:20
 1 18 20110715 16:14:19 20110715 16:15:46 20110715 16:15:47
 2 1 20110713 15:14:43 20110713 16:15:41 20110713 16:17:14
 2 2 20110713 16:15:41 20110713 16:32:50 20110713 16:32:54
 2 3 20110713 16:32:50 20110714 03:00:07 20110714 03:00:12
 2 4 20110714 03:00:07 20110714 03:00:23 20110714 03:00:27
 THREAD# SEQUENCE# FIRST_TIME NEXT_TIME COMPLETION_TIME
 ---------- ---------- ----------------- ----------------- -----------------
 2 5 20110714 03:00:23 20110714 06:00:06 20110714 06:00:11
 2 6 20110714 06:00:06 20110714 06:00:22 20110714 06:00:27
 2 7 20110714 06:00:22 20110714 06:00:37 20110714 09:47:56
 2 8 20110714 06:00:37 20110714 09:26:56 20110714 09:48:05
 2 9 20110714 09:26:56 20110714 09:47:56 20110714 09:48:05
 2 10 20110714 09:47:56 20110714 09:51:51 20110714 09:51:52
 2 11 20110714 09:51:51 20110714 09:52:12 20110714 09:52:12
 2 12 20110714 09:52:12 20110715 13:20:33 20110715 13:20:37
 区别已经很明显:
 list archivelog until time 'sysdate-1'; 此时是按照归档日志开始时间即fisrt_time作为截止时间
 list archivelog all completed before 'sysdate-1' 是按照归档日志完成时间即completion_time作为截止时间
 试想如果删除归档日志,还是采用delete archivelog all completed before 'sysdate-N'