Re: Diff between "controlfile autobackup" and "snapshot controlfile"

According to the fine manual, that isn't quite it either. :)

You can back up the control file when the database is mounted or open. RMAN uses a snapshot control file to ensure a read-consistent version. If CONFIGURE CONTROLFILE AUTOBACKUP is ON (by default it is OFF), then RMAN automatically backs up the control file and server parameter file after every backup and after database structural changes. The control file autobackup contains metadata about the previous backup, which is crucial for disaster recovery.

If the autobackup feature is not set, then you must manually back up the control file in one of the following ways:

• Run BACKUP CURRENT CONTROLFILE
• Include a backup of the control file within any backup by using the INCLUDE CURRENT CONTROLFILE option of the BACKUP command
• Back up datafile 1, because RMAN automatically includes the control file and SPFILE in backups of datafile 1

A manual backup of the control file is not the same as a control file autobackup. In manual backups, only RMAN repository data for backups within the current RMAN session is in the control file backup, and a manually backed-up control file cannot be automatically restored.

On Thu, 03 Feb 2005 11:48:58 +0100, Koen Van Langenhove <Koen.Van_Langenhove_at_siemens.com> wrote:
>
>
> Mladen Gogala wrote:
>
> >Sam Reddy wrote:
> >
> >
> >
> >>Why there are two of these options ?
> >>
> >>
> >>
> >>
> >>
> >There is no difference. Those two options both produce a backup of
> >controlfile which
> >can be used to recover database using backup controlfile. The two
> >options are here
> >to confuse the enemy.
> >
> >
> >
> Well, I had this slightly different opinion .. the snapshot controlfile
> is a backup creates before the actual backup starts in order to have a
> 'read consistent' view of the controlfile during the backup. The
> controlfile autobackup is the 'regular' backup of the controlfile and it
> is created after the datafile and eventually archivelog backups. I read
> this in R. Freeman's book 'RMAN backup and recovery' ..
>
> So I agree with Mladen that both can be used in recovery operations, but
> I think there's more to it than just confusing the enemy ;)
>
> --
> Regards,
> Koen
>
> Siemens ICM/ICN
> IC MN D IS
>
> Phone : +32 14 25 3000
> Email : Koen.Van_Langenhove_at_siemens.com
> - - - - - - -
> Unix IS user-friendly .., it's just quite picky about its friends.
>
> --
> http://www.freelists.org/webpage/oracle-l
>

-- 
Jared Still
Certifiable Oracle DBA and Part Time Perl Evangelist
--
http://www.freelists.org/webpage/oracle-l