Wednesday, 13 February 2013

When Controlfile Autobackup is generated, Why autobackup controlfile is not generated


Database Backup and Recovery User's Guide says 'The autobackup occurs whenever a backup record is added. If the database runs in ARCHIVELOG mode, then an autobackup is also taken whenever the database structure metadata in the control file changes"
http://docs.oracle.com/cd/E25178_01/backup.1111/e10642/rcmconfb.htm#i1017907

Out of curiosity to see how exactly it works,  just added a tablespace and checked my control file autobackup location to see the auto generated backup of controlfile. When i did 'ls' it was not showing any recent controlfile autobackups.

I rechecked all my configuration to make sure all setup is done right. After about 10 minutes i listed again  autobackup location, now i can see a new autobackup file is generated.

I spent sometime searching on google to see how long it takes and if the time it takes is configurable. I did not get much on its time lag .

Spending sometime on MOS searching for auto controlfile backup generation time gave me the answer to my question. With 11g 2 control file autobackup is implemented in a differed mode

RMAN CONTROLFILE AUTOBACKUP NOT CREATED DURING DB STRUCTURE CHANGE [ID 1068182.1]