Re: Periodic restart plusses and minuses?

Howard J. Rogers wrote:

> Hans Forbrich wrote:
>
> Good luck with finding that sort of material.
>
> Personally, and I realise this is not what you were after, I would simply
> ask "*what* automatic tuning benefits actually exist in 9i R2??". Because
> apart from the PGA, there aren't any that I can think of!
>
> DBMS_SHARED_POOL.KEEP and a suitable after startup trigger will "pre-warm"
> the library cache.
>
> The buffer cache will be cold, so physical reads will be needed to
> re-populate it, true enough. But we know that a 100% buffer cache hit
> ratio means nothing, and so a 0% hit ratio won't mean much either. And
> there's LOTS of information out there on that particular topic!!
>
> Ultimately, the only thing they can really do to sort this argument out is
> to run some performance tests after one or two shutdowns, and compare with
> normal "after several hours, even months" performance.
>
> And the guy advocating cold backups should be asked why he wants to do
> cold backups in the first place, given that he's in archivelog mode and
> has the choice... is it just a convenience thing? A lack of skills thing?
> A "I don't really know RMAN too well" thing? Or what??
>
> Regards
> HJR
Bingo - I think you hit it. I think the 'shutdown detunes' DBA want to use ratio-based tuning. (The other DBA ... 'we have always done it that way'!)

<sigh>
/Hans Received on Wed Oct 06 2004 - 08:00:51 CDT