Re: Use control file rebuild to increase log size

"Me" <Big_guy_at_gods.com> wrote in message news:YUMl9.422718$v53.19214482_at_news3.calgary.shaw.ca...
> Thanks for your response, Howard.
>
> In regards to your comments:
> - replacing the control file is the only way (AFAIK) to modify certain
> parameters (maxlogfiles, maxlogmembers, etc.) so it should be a safe
> operation.

True: this is the only way to alter those parameters, but that doesn't make it 'safe' -as I said, provided your trace file is up to date, there shouldn't be a problem. But if it was to be out of date (which, for this one-off exercise, I doubt) then there would be. Nasty ones.

> - I wanted to increase the maxlogfiles setting anyway so this is actually
a
> shortcut
> - I wanted to do this to 6 databases so it's a shortcut *

Fair enough, I guess. Brings home the point I always make though: when you *create* your databases, bung these parameters up to the max. Then they never need fiddling with subsequently. The cost? Oh, about an extra 200K or so of controlfile size. Not exactly worth worrying over. Not that this helps you any!!

>
> So the real question in my mind was whether there was any chance of data
> loss (shouldn't be if I shut down the database using transaction or
> immediate) or whether at some future time, the database would announce
that
> the files are somehow out of sync.
>

No, there's no possbility of data loss (wouldn't be much of a backup of the control file if there was!). Except in the case, as I said, of the trace file being old.

The effect of the resetlogs is to force synchronisation, so you won't get messages about out of sync files as a result merely of doing what you propose to do.

Regards
HJR
>
>
> "Howard J. Rogers" <howardjr2000_at_yahoo.com.au> wrote in message
> news:0rhl9.41755$g9.120510_at_newsfeeds.bigpond.com...
> |
> | "Me" <Big_guy_at_gods.com> wrote in message
> | news:vhal9.426767$Ag2.18093236_at_news2.calgary.shaw.ca...
> | > Hi,
> | >
> | > Everything I have read on the subject to date either implies or says
> | > outright that you can't use "resetlogs" in a control file rebuild to
> | > increase the size of the logs. Yet, I tried this and it worked fine.
> If
> | > I'm running noarchive (and don't care about the logs) and need to
> rebuild
> | > the control file anyway, are there any dangers to this?
> | >
> |
> | Well, the danger is that you are blowing away your existing control
files.
> | And you are putting your database into a new incarnation.
> |
> | The incarnation problem probably doesn't bother you, because you're not
in
> | archivelog mode anyway (it prevents future recoveries using previouos
> | backups and archives if you were). And for the same reason, I can't
think
> | why blowing your controlfiles away would be a major drama (RMAN backup
> | information gets stored in the controlfile, for example, which you'd
> | potentially lose).
> |
> | The only really serious problem is if the trace file that you use
doesn't
> | correctly describe the database you've got: say the trace file was
> generated
> | Monday, on Tuesday you added a new datafile, and you ran the Monday
script
> | on the Wednesday: you'd have lost data and have an unrecoverable
datafile
> on
> | your hands.
> |
> | It is an awfully long way round to achieve a simple redo log re-sizing
> | though.
> |
> | Regards
> | HJR
> |
> |
> | > TIA
> | >
> | >
> | >
> |
> |
>
>
Received on Sun Sep 29 2002 - 20:56:53 CDT