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Re: help recovering archives when all files in sync

From: Howard J. Rogers <howardjr_at_www.com>
Date: Sat, 21 Oct 2000 17:40:55 +1000
Message-ID: <39f13ae9@news.iprimus.com.au>

"frank" <fbortel_at_home.nl> wrote in message news:39F0915F.B8FE219D_at_home.nl...
>
> Syltrem wrote:
>
> > Hello!
> >
> > I was following this conversation and it raised a question:
> >
> > If I always do online backups (never offline), how do I restore my
 entire
> > database (let's say the whole place blew up)?
> >
> > Specifically:
> > Do I need to restore my redo log files from tape, or will the ALTER
 DATABASE
> > OPEN RESETLOGS create them?
>
> Of course you need them from tape, where else from? You just
> blew up your production server!
>
> >
> > Do I need to recreate the controlfile from a script (create controlfile
> > reuse...)
>
> reuse *what*?
>
> > or should I use the actual controlfiles that I saved to tape
> > during the backup?
>
> Interesting one: could it depend on time of the backup?
> I.e. if you backed up your control files last, you would
> do a recover database, if your datafile(s) are more recent, you
> would do recover using backup controlfile.
> Comments (Howard, Niall, Sybrand,...), please?
>

Hi Frank... The time of backup is irrelevant, because you have to include the keywords 'using backup controlfile' as part of the process, and that instructs SMON not to rely on the SCN in the Control File as the timestamp to which the rest of the database should synchronise. So it doesn't particularly matter one way or another as far as I can work out -myself, I'd still use the trace file script, suitably modified for the fact that the lack of Redo Logs means it can't successfully complete the recover and open commands it usually contains.

Regards
HJR
> >
> >
> > Thanks!
> >
> > "Howard J. Rogers" <howardjr_at_www.com> wrote in message
> > news:39f057ef$1_at_news.iprimus.com.au...
> > > Yes, don't restore the Control Files or online Redo Logs.
> > >
> > > If you restore everything from a cold backup, you have a perfectly
> > > synchronised database as at the time of the cold backup.
> > >
> > > What prompts the application of Archives is when SMON spots that the
> > > timestamps on the Control Files don't agree with the timestamps on
> > > everything else. So make sure you leave the Control Files at the
 point in
> > > time in the future, and bring back only the 'old' datafiles. The same
 goes
> > > for the Redo Logs (since you'll need their content to bring the
 database
> > > bang up to date -overwrite them with last night's backup, and you've
 just
> > > lost data).
> > >
> > > The rules of backup and recovery are really very simple -and the
 simplest
 of
> > > them all is, if you have archives, you only ever restore the files
 which
 are
> > > causing the problem, not the whole lot.
> > >
> > > Regards
> > > HJR
> > > --
> >



> > > Opinions expressed are my own, and not those of Oracle Corporation
> > > Oracle DBA Resources:

 http://www.geocities.com/howardjr2000
> >


> > >
> > > "Joe Gulla" <jgulla_at_erols.com> wrote in message
> > > news:8siobp$nb7$1_at_bob.news.rcn.net...
> > > > I was trying to recover data from point of a full cold backup to a
 time
 in
> > > > future. I have all archives
> > > > but since I replace all of database files from time of backup when I
 do
 a
> > > > recover all instance is in ssync.
> > > > Is there a way around this?
> > > > Joe G
> > > >
> > > >
> > >
> > >
>
Received on Sat Oct 21 2000 - 02:40:55 CDT

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