Re: Backup Oracle ? Online Redo Log.

Thomas Kyte <tkyte_at_us.oracle.com> wrote in message news:<a1kl7s011fm_at_drn.newsguy.com>...

> > Howard J. Rogers wrote:

> You do not backup online redo log, it is never necessary, even with a cold
> backup (cold backups should be done after a shutdown immediate or normal, redo
> logs are not necessary to recover).
>
> >> when it comes time to recovery. Without doubt, the current redo log is
> the
> >> Achilles' heel of the entire Oracle architecture -which is why they
> invented
> >> redo log mirroring (or, more accurately) multiplexing so that total loss
> of
> >> the current log should be a very rare occurrence -making attempted backups
> >> of it even more of a waste of time than they otherwise would be.

OK Guys, what do you make of the metalink Note 1034098.6 where they explain you do want to if you want to restore from a cold backup without applying archive logs?

• Begin inclusion ------------------------

If a full restore of the database to the point in time of the backup is
intended, both the control file and redo logs can be restored with the datafiles. This will allow the database to open from the point it was shutdown for the backups. This is the only time that recovery of the redo
logs can assist recovery.

If the redo logs were not recovered, the recovery to a point back in time
would require a resetlog to open the database.

Explanation

By default, the online redo logs are not backed up in the scripts. This is
documented in the EBU manual. If roll forward is not performed, or in noarchive mode, the backup and restore of online redo logs will eliminate the
need for resetlogs when opening the database.

• End inclusion

  ---

Personally, I think the idea of having a backup that can be restored from with minimal DBA work is pretty attractive, especially in cases of non-online-production instances like reporting or development or pseudo-DW IAS where archive logging is just a waste of resources or important-point-in-time breakpoints (like before a huge app upgrade) where any restoration wouldn't be to something working. Maybe take exports to help out klutzy developers.

jg

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