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Richard,
I think that you are still missing Jared's point.
It is quite right of you to say that a DBA should do a consistent backup
and that
one who does not run his backups properly is committing a sin.
Jared has already explained two examples of why you would want the online
backups
included in a Cold Backup. And I reiterate them here.
I always run a switch logfile or archive log current before backing up archive logs in a Hot Backup but do not backup online redo logs with the Hot Backup. With a Cold Backup I always backup the online redo logs as well. [Tough luck for me if I join an organisation and I am the guy that got hit on that 6th day because the previous DBA's scripts weren't doing a proper shutdown].
Also, although many DBAs know that you can bring up a properly shutdown and backed up cold database without the online redo logs as they know the OPEN RESETLOGS command, not all DBAs know this. Suppose the person is a trainee-DBA or an SA or a Damager. He's going to curse Oracle when he finds that he can't bring up his database although he did a "complete" backup [using the guidance provided in the 9iR2 manual which so helpfully told him not to backup the online logs but he has never read about how and when to run an OPEN RESETLOGS].
Therefore, the advice NOT to backup online redo logs is patently dangerous.
The advice should be to backup online redo logs already on disk before beginning a restore. In fact, that is always a standing instruction in any Oracle Database recovery -- backup what you currently have on disk, no matter how badly "hosed" before you begin the recovery.
Hemant
At 04:56 AM 25-05-03 -0800, you wrote:
> > Richard,
> >
> > You must have missed one. :)
>
>Hi Jared,
>
>I think we're going to have to introduce quotas, no more than two
>contributions per thread ;)
>
> >
> > There have been 2 occasions where someone has
> > sent me 200 gb worth of database on tape, and
> > the database had not been shutdown properly.
> >
> > Since the system datafile needed recovery from
> > the online logs, I was very glad to have them.
>
>I guess my point is that making a backup without shutting down the system
>properly is a sin akin to scratching a rare David Bowie LP, ie. somewhat
>unforgivable (although I admit the second sin is far worse). Make a
>consistent backup and/or have the database in archivelog mode, you then
>don't require the online redo logs ....
>
> >
> > I have encountered this on a very few other
> > occasions, but can't recall the circumstances
> > of those events.
> >
> > They are also useful when cloning a DB (without RMAN),
> > though not required. Depends on how the clone
> > will be used.
>
>I guess my point here is the "though not required" bit. It simplifies the
>process I agree but even in this case, the online logs are not strictly
>required.
>
> >
> > As with many things, this is not a black and white
> > issue. There are shades of gray. While it certainly
> > not necesssary to normally backup the online logs
> > during a cold backup, it is incorrect to say that
> > they are never useful.
> >
>
>I guess we're going to have to agree to disagree. However, getting back to
>the subject of sins, including online redo logs in a cold backup is not
>really an issue that would cause me loss of sleep (unlike scratching DB
>LPs). Like, it doesn't really hurt. But if someone were to accidentally
>incorrectly restore them in a recovery scenario, ouch, that would be a sin
>worth having a chat about ;)
>
>Cheers
>
>Richard
>
>
>--
>Please see the official ORACLE-L FAQ: http://www.orafaq.net
>--
>Author: Richard Foote
> INET: richard.foote_at_bigpond.com
>
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Hemant K Chitale
Oracle 9i Database Administrator Certified Professional
My personal web site is : http://hkchital.tripod.com
-- Please see the official ORACLE-L FAQ: http://www.orafaq.net -- Author: Hemant K Chitale INET: hkchital_at_singnet.com.sg Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).Received on Sun May 25 2003 - 11:21:39 CDT