Re: Help recovering from hotbackup

> Howard,
>
> Go easy, please.
>
> What happens if you lose all the online redo logs (yes I know they are
> supposed to be multiplexed)?

Actually, there's only ever one online log (OK, maybe briefly two, whilst one's being checkpointed). The other 'online logs' have of course already been backed up. That's what ARCH does.

> Yes, you can recover the database, but surely you lose the last few
minutes
> worth of updates?
>

Entirely true. But so what? That's not an argument for backing up the online logs, is it? It's rather an argument for multiplexing.

Suppose you backup the online logs, against all Oracle's advice, RMAN's in-built capabilities, and my repeated entreaties not to. That was last night. How is restoring a 9-hour old 'online log' going to help you *not* lose the last transactions that were contained in the real-life online logs?

If you lose your online logs, you have absolutely no alternative but to do a 'recover until cancel', cancel when it prompts you for what you know to be the missing logs, and then open resetlogs. At which point you get your online logs back... but, yes, missing the last dollop of redo, and hence with some lost transactions.

The *only* thing you can do to prevent that is multiplex.

Backing up the online logs doesn't help at all.

Cheers
HJR
> Regards,
> Paul
>
>
>
Received on Fri Dec 20 2002 - 17:21:00 CST