Re: How to apply archive logs on an cold backup

From: Frank van Bortel <fvanbortel_at_netscape.net>
Date: Mon, 06 Sep 2004 12:05:36 +0200
Message-ID: <chhccd$556$1@news1.tilbu1.nb.home.nl>

Howard J. Rogers wrote:
> Frank:
>
> I'm not heated or itchy. This isn't a matter of personalities. And it is
> disappointing that you attempt to make it so. If you must search for an
> adjective to apply to me personally, try 'passionate', because I am very
> passionate about not misleading newbies with dangerous and misleading
> advice constructed on nothing more than wild assumptions.

I know you're passionate. And you started accusing me of hinting you were wrong.

>
> Bob posted simplistic and dangerous advice. He didn't like it when I called
> him on it. He can't justify his post on any technical grounds. I have
> talked about nothing but the technicalities of the matter since. Or at
> least tried to.
>
> If you wish to get thoughtful and musing to the world in general, be my
> guest. But don't start speculating wildly about things that are not
> factual, in a post made physically in reply to one of mine, including an
> apparent accusation that I said things I never did, and expect me to be
> totally neutral about it, OK?

So you do take it personal - good; so do I. I don't like being accused of things that never happened, either.

You said:
 > Just don't start saying my answer is wrong when what you've actually done is
 > completely change the question!
 >

And my reaction to that was:
This (part of this) thread was not solely intended for you (I just had to reply somewhere...) to start with, so do not feel spoken to when not.
And don't put words in my mouth, either. There is not one sentence in the -admiringly crappy- english I wrote, that could let you believe I was saying your answer was wrong - where did you read that?!?

So where's the "apparent accusation"?
>
> On that last specific issue, here is what you wrote:
>
> Howard - why would this scenario never arise?

You wrote in a reply to Tim, on Sep, 1st, 10:02AM: <quote>
...
You've effectively just cloned your database.

 >> 2)  In the same scenario as above, assuming you have archive logs
 >> available from the time of the cold backup up to "now", how would you
 >> roll that cold backup forward?  It was in this case that I thought you
 >> had to use a RECOVER .... USING BACKUP CONTROLFILE, after creating a
 >> new control file from a script?

Of course. You're wanting to perform recovery with a backup controlfile. Strangely enough, that requires the use of the 'using backup controlfile' command.

If you're trying to say, 'That's the OP's situation!', I'd remind you of the point I made at the beginning of this post: if you're in archivelog mode, you shouldn't be taking backups of your online redo logs in the first place, meaning that this entire scenario would never actually arise.

</quote>
>

>>What scenario? Using backup controlfile?

>
> The scenario I tried to depict in the previous thread.
>

>>When did I ever say it never would arise??

>
> Just reread your contributions to this thread
>
> Here is what is in the fourth post (according to my newsreader) in this
> thread:
>
> "The 'using backup controlfile' clause should only be specified if that's,
> strangely enough, actually what you're using. Unless he restores his
> control files from backup, it would be lunacy to use the clause."
>
> Here is my first post to Tim:
> "ONLY if (1) you are in archivelog mode and (2) you have a backup
> (temperature irrelevant) and (3) you lose EVERY copy of your control file
> and (4) you only have a binary backup of the control file
>
> ...only then do you issue the command 'recover database using backup
> controlfile'."
>
> Here is another post I made in reply to Tim:
> "Of course. You're wanting to perform recovery with a backup controlfile.
> Strangely enough, that requires the use of the 'using backup controlfile'
> command."
>
> Here is my penultimate reply to Tim:
> "The correct recovery procedure for this sort of scenario is simply to
> restore the control files and data files from your backup, and issue the
> command 'recover database until cancel using backup controlfile'. You could
> do an 'until time' if you know those sorts of detail, but usually it's an
> until cancel when lost redo logs are involved."
>
> And I could go on.
>
> I have repeatedly said, using backup controlfile is a valid command to use
> under the right circumstances.
>
> So, I did what you asked, and re-read my contributions to this thread. Will
> you now therefore acknowledge that your hint that I said otherwise was
> inappropriate?

Where did I hint that?!? I never did; there's no comments on the technical details from my side in any of this threads' messages. Your hinting that I was
>
> And as a specific explanation of what was wrong with your 'scenario', please
> see my response to Tim, because it is (as far as I can tell) exactly the
> same scenario he came up with.
>
> "AFAICT, the OP wants to recover (PITR), but only happens
> to have a cold backup, and all online, and off-line
> redo log files.
> Now, you can restore your cold*) backup, and everything
> is honkey-dorey; however, you lost 2 days of data."
>
> Now, your asterisk indicated that the OP would have restored
> "Controlfile(s), online redolog files, datafiles, (S)PFILE(s),
> directory structures, password file"
>
> And if that's the case, all bets are off because he's just performed a wrong
> restoration.

You lost me here - isn't this the restore of a cold backup?!? On sep, 1st, 10:02AM you wrote:
<quote>
If you restore the binary control files, all data files and all online redo logs from a closed, whole backup (ie, cold), then recovery will not be required, because indeed everything agrees as to SCN.

You've effectively just cloned your database. </quote>
Looks like we're in agreement on this one, but I just don't seem to get that across - and I'll take the blame for that.

 > If he'd just restored the controlfile, the datafiles, the
> directory stuctures and so on, and NOT the online redo logs, then recovery
> is possible up to the point of the last log switch. No sweat, no worries,
> and no concerns whatsoever about the temperature of his backup.
>
> And as I also said to Tim, could we please stop positing scenario after
> scenario, with rusty tapes and God knows what else? It rarely helps. The
> fundamentals never change, whatever the scenario. Don't backup your online
> logs; Restore what is broken; Construct a recovery command.
Couldn't agree more with that. Don't panic, think, [your 3 points]

I did -intentionally!- not post a scenario; on the contrary, I stated the discussion would be academic - the OP did NOT reveal his problem, so all else is guessing and imagination. As I did. As I admitted earlier.

-- 

Regards,
Frank van Bortel

PS I do not wish to take this any further:
* technically speaking I agree with you
* personally, passionate or itchy, I see no proof for
   your accusations of any hints or accusations I made,
   but I'll make my excuses for them, here and now.
* no one would be interested in this part of the thread for
   the right reasons.

Received on Mon Sep 06 2004 - 05:05:36 CDT