Re: Handling of archive logs

"Stefan Fournier" <Stefan.Fournier_at_gmx.de> wrote in message news:8FD570E85StefanFourniergmxde_at_130.133.1.4...
> howardjr_at_www.com (Howard J. Rogers) wrote in
> <39f14211$1_at_news.iprimus.com.au>:
>
> >The realist in me says if you think you can get away with it, why not?
> >
> >The purist in me says... the archive logs are the only thing standing
> >between you and data loss, so you play around with them at your peril.
> >Compression to me sounds like a very *bad* idea, since you are rather
> >relying on the compression working correctly, and the decompression to
> >work without a hitch when needed. Anything goes wrong at either end,
> >and you've just lost your logs, and hence the data they were supposed to
> >be protecting.
>
> I think compressing/uncompressing a file with gzip is absolutely reliable.

I'm sure you do, otherwise you wouldn't be doing it. The law of probability, however, not to mention his close cousin, Murphy, (not to mention his maternal niece, common sense) clearly indicates that it *must* be riskier to compress than to do nothing.

> It makes me more headaches to have the logs just on some DLT's, which
> are not as reliable as having files on the disk already.
> And it's also much quicker to decompress files on the disk than restoring
> them from a tape.
>

It's definitely better to have uncompressed archives on disk than to have to go to the bother of loading them off tape, agree absolutely. On the other hand, if you are now saying that your *only* source of archives is from disk, then you are riding for a fall. Ever heard of a head crash? They *do* happen.

>
> >
> >Managerially, it's also suspect: when the database goes down, your job
> >is supposed to be to get it back up and running again as quickly as
> >humanly possible. By compressing your logs, however, you've introduced
> >another stage in the process, and hence meantime to recover will
> >inevitably be longer.
>
> Well, you just have to think of it. If the database wants archived redo
> logs and doesn't find them, don't get nervous but remember that you
> zipped them.

...and spend time unzipping them. Time was my point, not your powers of memory.

> But you're right to say to keep things as simple as possible.
>

But not *so* simple you compromise recoverability -which is what you are, in fact, doing.

Regards
HJR
> Regards,
> Stefan
>
> --
> Stefan.Fournier_at_gmx.de
Received on Sun Oct 22 2000 - 15:57:18 CDT