Most Internet references about defining the ArchiveLog Deletion Policy relate to the necessity to preserve ArchiveLogs for Standby databases.
For example, the configuration here prevents deletion unless an ArchiveLog has been applied on a Standby :
But it is possible to also configure it differently. For example, thus for a database without a Standby, I can configure it to prevent deletion unless a Backup of the ArchiveLog has been made (to disk in this case) :
Let's see how this plays.
RMAN raised a WARNING that indicates that deletion of the ArchiveLog is not permitted until a Backup has been taken. Thus, you can protect your ArchiveLogs from deletion by RMAN commands if they have not been backed up.
NOTE : This does NOT prevent non-RMAN commands (e.g. cron jobs with shell scripts) from deleting ArchiveLogs !
Let me backup and then delete the ArchiveLogs.
Now, I am able to delete the ArchiveLogs as I have at least 1 backup (on disk) of each.
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For example, the configuration here prevents deletion unless an ArchiveLog has been applied on a Standby :
RMAN> show all; RMAN configuration parameters for database with db_unique_name ORCL are: CONFIGURE RETENTION POLICY TO REDUNDANCY 1; # default CONFIGURE BACKUP OPTIMIZATION OFF; # default CONFIGURE DEFAULT DEVICE TYPE TO DISK; # default CONFIGURE CONTROLFILE AUTOBACKUP ON; CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '%F'; # default CONFIGURE DEVICE TYPE DISK PARALLELISM 2 BACKUP TYPE TO BACKUPSET; CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default CONFIGURE MAXSETSIZE TO UNLIMITED; # default CONFIGURE ENCRYPTION FOR DATABASE OFF; # default CONFIGURE ENCRYPTION ALGORITHM 'AES128'; # default CONFIGURE COMPRESSION ALGORITHM 'BASIC' AS OF RELEASE 'DEFAULT' OPTIMIZE FOR LOAD TRUE ; # default CONFIGURE ARCHIVELOG DELETION POLICY TO APPLIED ON ALL STANDBY; CONFIGURE SNAPSHOT CONTROLFILE NAME TO '/home/oracle/app/oracle/product/11.2.0/dbhome_2/dbs/snapcf_orcl.f'; # default RMAN>
But it is possible to also configure it differently. For example, thus for a database without a Standby, I can configure it to prevent deletion unless a Backup of the ArchiveLog has been made (to disk in this case) :
RMAN> configure archivelog deletion policy to backed up 1 times to device type disk; old RMAN configuration parameters: CONFIGURE ARCHIVELOG DELETION POLICY TO APPLIED ON ALL STANDBY; new RMAN configuration parameters: CONFIGURE ARCHIVELOG DELETION POLICY TO BACKED UP 1 TIMES TO DISK; new RMAN configuration parameters are successfully stored RMAN> show all; RMAN configuration parameters for database with db_unique_name ORCL are: CONFIGURE RETENTION POLICY TO REDUNDANCY 1; # default CONFIGURE BACKUP OPTIMIZATION OFF; # default CONFIGURE DEFAULT DEVICE TYPE TO DISK; # default CONFIGURE CONTROLFILE AUTOBACKUP ON; CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '%F'; # default CONFIGURE DEVICE TYPE DISK PARALLELISM 2 BACKUP TYPE TO BACKUPSET; CONFIGURE DATAFILE BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default CONFIGURE ARCHIVELOG BACKUP COPIES FOR DEVICE TYPE DISK TO 1; # default CONFIGURE MAXSETSIZE TO UNLIMITED; # default CONFIGURE ENCRYPTION FOR DATABASE OFF; # default CONFIGURE ENCRYPTION ALGORITHM 'AES128'; # default CONFIGURE COMPRESSION ALGORITHM 'BASIC' AS OF RELEASE 'DEFAULT' OPTIMIZE FOR LOAD TRUE ; # default CONFIGURE ARCHIVELOG DELETION POLICY TO BACKED UP 1 TIMES TO DISK; CONFIGURE SNAPSHOT CONTROLFILE NAME TO '/home/oracle/app/oracle/product/11.2.0/dbhome_2/dbs/snapcf_orcl.f'; # default RMAN>
Let's see how this plays.
RMAN> sql 'alter system archive log current '; sql statement: alter system archive log current RMAN> delete archivelog all; released channel: ORA_DISK_1 released channel: ORA_DISK_2 allocated channel: ORA_DISK_1 channel ORA_DISK_1: SID=35 device type=DISK allocated channel: ORA_DISK_2 channel ORA_DISK_2: SID=52 device type=DISK RMAN-08138: WARNING: archived log not deleted - must create more backups archived log file name=/NEW_FS/oracle/FRA/ORCL/archivelog/2015_06_13/o1_mf_1_623_bqrjp5gx_.arc thread=1 sequence=623 RMAN-08138: WARNING: archived log not deleted - must create more backups archived log file name=/NEW_FS/oracle/FRA/ORCL/archivelog/2015_06_13/o1_mf_1_624_bqrjpsb3_.arc thread=1 sequence=624 RMAN-08138: WARNING: archived log not deleted - must create more backups archived log file name=/NEW_FS/oracle/FRA/ORCL/archivelog/2015_06_13/o1_mf_1_625_bqrjq8kj_.arc thread=1 sequence=625 RMAN-08138: WARNING: archived log not deleted - must create more backups archived log file name=/NEW_FS/oracle/FRA/ORCL/archivelog/2015_06_13/o1_mf_1_626_bqrjqfdq_.arc thread=1 sequence=626 RMAN>
RMAN raised a WARNING that indicates that deletion of the ArchiveLog is not permitted until a Backup has been taken. Thus, you can protect your ArchiveLogs from deletion by RMAN commands if they have not been backed up.
NOTE : This does NOT prevent non-RMAN commands (e.g. cron jobs with shell scripts) from deleting ArchiveLogs !
Let me backup and then delete the ArchiveLogs.
RMAN> backup as compressed backupset archivelog all;
Starting backup at 13-JUN-15
current log archived
using channel ORA_DISK_1
using channel ORA_DISK_2
channel ORA_DISK_1: starting compressed archived log backup set
channel ORA_DISK_1: specifying archived log(s) in backup set
input archived log thread=1 sequence=623 RECID=9 STAMP=882312517
channel ORA_DISK_1: starting piece 1 at 13-JUN-15
channel ORA_DISK_2: starting compressed archived log backup set
channel ORA_DISK_2: specifying archived log(s) in backup set
input archived log thread=1 sequence=624 RECID=10 STAMP=882312537
input archived log thread=1 sequence=625 RECID=11 STAMP=882312552
input archived log thread=1 sequence=626 RECID=12 STAMP=882312557
channel ORA_DISK_2: starting piece 1 at 13-JUN-15
channel ORA_DISK_1: finished piece 1 at 13-JUN-15
piece handle=/NEW_FS/oracle/FRA/ORCL/backupset/2015_06_13/o1_mf_annnn_TAG20150613T225210_bqrjwtfd_.bkp tag=TAG20150613T225210 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
channel ORA_DISK_1: starting compressed archived log backup set
channel ORA_DISK_1: specifying archived log(s) in backup set
input archived log thread=1 sequence=627 RECID=13 STAMP=882312730
channel ORA_DISK_1: starting piece 1 at 13-JUN-15
channel ORA_DISK_2: finished piece 1 at 13-JUN-15
piece handle=/NEW_FS/oracle/FRA/ORCL/backupset/2015_06_13/o1_mf_annnn_TAG20150613T225210_bqrjwtg3_.bkp tag=TAG20150613T225210 comment=NONE
channel ORA_DISK_2: backup set complete, elapsed time: 00:00:01
channel ORA_DISK_1: finished piece 1 at 13-JUN-15
piece handle=/NEW_FS/oracle/FRA/ORCL/backupset/2015_06_13/o1_mf_annnn_TAG20150613T225210_bqrjwvp1_.bkp tag=TAG20150613T225210 comment=NONE
channel ORA_DISK_1: backup set complete, elapsed time: 00:00:01
Finished backup at 13-JUN-15
Starting Control File and SPFILE Autobackup at 13-JUN-15
piece handle=/NEW_FS/oracle/FRA/ORCL/autobackup/2015_06_13/o1_mf_s_882312732_bqrjwwsc_.bkp comment=NONE
Finished Control File and SPFILE Autobackup at 13-JUN-15
RMAN> delete archivelog all;
released channel: ORA_DISK_1
released channel: ORA_DISK_2
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=35 device type=DISK
allocated channel: ORA_DISK_2
channel ORA_DISK_2: SID=52 device type=DISK
List of Archived Log Copies for database with db_unique_name ORCL
=====================================================================
Key Thrd Seq S Low Time
------- ---- ------- - ---------
9 1 623 A 07-JUN-15
Name: /NEW_FS/oracle/FRA/ORCL/archivelog/2015_06_13/o1_mf_1_623_bqrjp5gx_.arc
10 1 624 A 13-JUN-15
Name: /NEW_FS/oracle/FRA/ORCL/archivelog/2015_06_13/o1_mf_1_624_bqrjpsb3_.arc
11 1 625 A 13-JUN-15
Name: /NEW_FS/oracle/FRA/ORCL/archivelog/2015_06_13/o1_mf_1_625_bqrjq8kj_.arc
12 1 626 A 13-JUN-15
Name: /NEW_FS/oracle/FRA/ORCL/archivelog/2015_06_13/o1_mf_1_626_bqrjqfdq_.arc
13 1 627 A 13-JUN-15
Name: /NEW_FS/oracle/FRA/ORCL/archivelog/2015_06_13/o1_mf_1_627_bqrjwt3k_.arc
Do you really want to delete the above objects (enter YES or NO)? YES
deleted archived log
archived log file name=/NEW_FS/oracle/FRA/ORCL/archivelog/2015_06_13/o1_mf_1_623_bqrjp5gx_.arc RECID=9 STAMP=882312517
deleted archived log
archived log file name=/NEW_FS/oracle/FRA/ORCL/archivelog/2015_06_13/o1_mf_1_624_bqrjpsb3_.arc RECID=10 STAMP=882312537
deleted archived log
archived log file name=/NEW_FS/oracle/FRA/ORCL/archivelog/2015_06_13/o1_mf_1_625_bqrjq8kj_.arc RECID=11 STAMP=882312552
deleted archived log
archived log file name=/NEW_FS/oracle/FRA/ORCL/archivelog/2015_06_13/o1_mf_1_626_bqrjqfdq_.arc RECID=12 STAMP=882312557
deleted archived log
archived log file name=/NEW_FS/oracle/FRA/ORCL/archivelog/2015_06_13/o1_mf_1_627_bqrjwt3k_.arc RECID=13 STAMP=882312730
Deleted 5 objects
RMAN>
Now, I am able to delete the ArchiveLogs as I have at least 1 backup (on disk) of each.
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4 comments:
Good one
How abt retention policy required by replication software like golden gate
You'd have to ensure that there is enough space for Oracle to retain enough ArchiveLogs for GoldenGate and not automatically purge them.
...or you can set alternative archivelog destination in goldengate with altarchivelogdest parameter and by coping(with manualy or with script) archivelogs before deletion policy occurs to this alternative location.
...or you can set altarchivelogdest parameter in GoldenGate as your secondary archivelog location and by manually/automatically copy archivelogs to this location.
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