Re: Recovery Catalog vs Control File

On Fri, 29 Aug 2008 11:17:42 -0700 (PDT), exec_at_chicagorsvp.com wrote:

>On Aug 29, 8:47 am, hpuxrac <johnbhur..._at_sbcglobal.net> wrote:
>> On Aug 29, 9:07 am, e..._at_chicagorsvp.com wrote:
>>
>> > I've read a lot about this concept, Recovery Catalog vs Control File.
>> > I'm just looking for some real life experience comments.
>>
>> > I've always thought that using a recovery catalog only gives you yet
>> > another instance to back up.
>>
>> > What are some of your experiences.......it'd help me make my
>> > decision.  Reading is not the same as getting real life comments......
>>
>> Before 9i if you were using rman ( it was pretty darn unstable at best
>> in the 8x days anyways ) you pretty much had to use a recovery
>> catalog.
>>
>> At 9i level it became somewhat more optional ( having a recovery
>> catalog or not ).
>>
>> At 10g and above the recovery catalog concept may not make a lot of
>> sense unless you have a whole bunch of databases to manage ( whatever
>> a whole bunch means mileage may vary ) ...
>>
>> That's my short summary.
>>
>> There's a bunch of synchronization work needed at times in terms of
>> levels of the recovery catalog and levels of the databases you are
>> backing up and levels of the software to do the rman backups if you do
>> go the recovery catalog way.
>
>What does this mean, and what is the purpose of the different control
>file backup methods?
>
>
>The RMAN behavior when the BACKUP command includes datafile 1 depends
>on the CONFIGURE CONTROLFILE AUTOBACKUP setting. If control file
>autobackups are ON and the backup includes datafile 1, RMAN writes the
>control file and SPFILE to a separate autobackup backup set. If
>control file autobackups are OFF and the backup includes datafile 1,
>then RMAN includes the current control file and SPFILE in the same
>backup set as the datafiles.

The controlfile autobackup is stored in a file including the dbid of the database, the date in the format yyyymmdd and a piece number. It can be restored seperately and it pretty much replaces the ... recovery catalog.

If you know the dbid and controlfile autobackup is on, you can always restore the database.

-- 
Sybrand Bakker
Senior Oracle DBA