Re: Transaction Gradually Slows to a crawl! (please help)

"Ryan Gaffuri" <rgaffuri_at_cox.net> wrote in message news:1efdad5b.0305291202.657dbf87_at_posting.google.com...
> Sybrand Bakker <gooiditweg_at_sybrandb.demon.nl> wrote in message
news:<pdf8dv0tnk92h7su850a04ij2stmugknh0_at_4ax.com>...
> > On Wed, 28 May 2003 02:16:44 GMT, "Ryan" <rgaffuri_at_cox.net> wrote:
> >
> > >how do you disable redo logs? you can generate no redo? really? i have
a
> > >staging database also.
> >
> >
> > Yes, you can. But the redo log mechanism still will be called, it only
> > won't write. And of course: you render your database in an UNSUPPORTED
> > state.
> > Such act is only for the brave/stupid (cross all that apply), and is
> > usually considered only by people who don't want cures but just
> > figthing symptoms.
> >
> >
> > Sybrand Bakker, Senior Oracle DBA
> >
> > To reply remove -verwijderdit from my e-mail address
>
> if I have an instance failure with this turned off, what happens on
startup?

Your database crashes. And it can never be re-started. An instance failure requires the application of redo from the current redo log. With _disable_logging=TRUE, then that redo won't be available, because it was never written to the current log in the first place. Therefore, you can't do instance recovery. Therefore, the database is toast. (I found this out the hard way once having demonstrated what _disable_logging does, finished the demo, changed my init.ora back to remove the parameter, and then -suffering a complete brainstorm- issued a startup force command to get the new init.ora re-read. Startup force does a shutdown abort... I had just crashed the instance. That wasn't just the end of the demo, but the end of that week's teacher's account!!).

All you can do in such a situation is to delete every single log file, data file and control file, and restore the lot from the closed, consistent backup you took before invoking the _disable_logging=true option.

And if you don't have a closed, whole database backup, you're going to be in deep, deep doo-doo.

(I'm assuming that you'd have switched off archiving if you're going for _disable_logging. But if you've got a hot backup and some archives, you'd probably be able to get the database back to some sort of usable state using that. It would still be very messy, though, and very much an incomplete recovery).

Regards
HJR Received on Thu May 29 2003 - 15:13:40 CDT