Re: Redo's with cold backup

In message <337A94E2.3AF7_at_teldta.com>

        "Brian P. Mac Lean" <brian.maclean_at_teldta.com> writes:

> Adrian Beane wrote:
> >
> > In message <3378859E.7F99_at_teldta.com>
> > "Brian P. Mac Lean" <brian.maclean_at_teldta.com> writes:
> >
> > > Also, understand that if you know your stuff, you can get to the
> > > point that a cold backup is not necessary. You can do recovery
> > > using only hot backups providing you have all the pieces (think 7X24).
> >
> > I already run 7x24 with hot backups, archived redo logs and control
> > file backups. It had never occured to me that you could (would want
> > to) use archived redo logs with a cold backup of the database.
> >
> > I was thinking in terms of a full database recovery which brings up a
> > consistent day day old Oracle database which leaves you with a day's
> > worth of redo logs that need applying.
 

> --
 

> The point/issue of your last comment is "consistent".
> You can restore any datafile from a hot or cold backup and roll it
forward to > the current point in time if you have all redo's + the current redo log, or
> roll it forward to the point you run out of archives.
> The key is in the control file you use and what that control file
 thinks > is "consistent".
> If you didn't loose the "current" control files in the crash, use
them. They will > get that cold/hot datafile back to "current". If you lost the "current" control
> files in the crash, use the output from the "alter database backup
controlfile > to 'filename'" command (you doooooooo run one with each hot and cold backup don't
> you?!!!) as your control file.

Yes indeed. Infact I do one at the start of the session and one at the end to a different file. I even used to keep the files on two separate sources of backup media ie a disk as well as on a tape.

> This control file allows you to do what I call an
> open ended recovery. The control file doesn't know the highest
scn/archive# so it > will prompt you for archives until you run out, cancel the recovery,
> and open the database resetting the redo's. The use of the "backup
 controlfile"
> is more or less the same as what Oracle now calls a standby
 database. In 7.3
> they added a few commands to jazz it up, but it's still the same game.
 

> I hope this helps, if not, e-mail me your phone#, I'll call, we'll talk.

No need. That answers the question exactly. I just wish I had asked it a bit more clearly in the first place. Thanks. Received on Thu May 15 1997 - 00:00:00 CDT