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Re: Query Database while shutdown in progress

From: Andrew Kerber <andrew.kerber_at_gmail.com>
Date: Wed, 27 Jun 2007 14:12:45 -0500
Message-ID: <ad3aa4c90706271212q7c1e1d2ds5dca8a21a3c0a5ed@mail.gmail.com>


The last time I checked, admittedly in the 8.1.7 world, oracle stated that you could end up with file corruption on a shutdown abort (note that is could, not would, I never had it happen), If they have changed this and now say that a shutdown abort is as safe as a shutdown immediate, I have not heard it. Does anyone have a statement from oracle to that effect?

What happens if you have datafiles in backup mode and you try and do a startup force?

On 6/27/07, Robert Freeman <robertgfreeman_at_yahoo.com> wrote:
>
> On 6/27/07, Andrew Kerber <andrew.kerber_at_gmail.com> wrote:
>
> > Sometime shutdown abort is necessary. However, its not recommended. I
> > would rather not risk having to recover a database w/o a good reason. If
> > all that is needed is to monitor a shutdown immediate. there are a lot of
> > ways to handle that. If nothing else, you can tail the alert log, and see
> > the id thats keep the instance form shutting down, then kill that session.
> > That would be much safer than an abnormal termination of the instance.
> >
>
> I agree with Jared, whats up with this? Yes, a shutdown abort assures that
> you will be doing crash/instance recovery, but so what? If you are truly
> concerned about that, do a checkpoint before you do the shutdown abort
> (assuming that does not take forever). In what cases will a shutdown require
> media recovery? I know of none unless you are planning on rm'ing a bunch of
> datafiles afterwards.
>
> One of the beauties of Oracle, and a fact that seems little known, is the
> rule with regards to checkpoints and redo logs. Everyone knows that a redo
> log can not be reused in ARCHIVELOG mode until the archived redo log is
> created. What seems less known is the rule that an online redo log can not
> be reused until all dirty blocks associated with that online redo log have
> been checkpointed and written to the datafiles. Thus, shutdown abort should
> NEVER lead to a media recovery.
>
> I will say, as a point of caution, that back in the 7.x days, there was a
> bug that I discovered that would cause you to have to do media recovery
> after a shutdown abort. So if you are running 7.x then be careful about a
> shutdown abort.
>
> RF
>
> Robert G. Freeman
> Oracle Consultant/DBA/Author
> Principal Engineer/Team Manager
> The Church of Jesus Christ of Latter-Day Saints
> Father of Five, Husband of One,
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> !
> Sig V1.1
>
>
>
>

-- 
Andrew W. Kerber

'If at first you dont succeed, dont take up skydiving.'

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Received on Wed Jun 27 2007 - 14:12:45 CDT

Original text of this message

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