Re: yipeee!

Holger Baer wrote:

> I'm still wondering how
> the node I failed over to is able to bypass that restriction. It was a
> question
> the teacher of my RAC course couldn't quite answer, but then maybe he just
> knew so much more of the internal mechanics that he needn't to wonder ;-)
>
> Cheer up, that cast on your leg won't last forever ;-)
>
> Holger

Thanks ... just 11 more days.

The way it is done is through something a combination of shared everything ... meaning that each node sees the same database files, the same data, and can also see the same redo logs and rollback segements. Thus if one node fails ... any other node can see everything on disk that was in use by any other node. Add to that cache fusion ... the ability to pass memory caches between nodes and the only thing one node needs to know about another node to fail-over is what failed and where. We routinely see restarts in the <60 second range.

-- 
Daniel Morgan
http://www.outreach.washington.edu/ext/certificates/oad/oad_crs.asp
http://www.outreach.washington.edu/ext/certificates/aoa/aoa_crs.asp
damorgan_at_x.washington.edu
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