Re: CPU being hit hard by a query

From: Mark Bole <makbo_at_pacbell.net>
Date: Wed, 25 Aug 2004 09:57:24 GMT
Message-ID: <8oZWc.12028$JD1.6227@newssvr29.news.prodigy.com>

Ana C. Dent wrote:

> Harry_Boswell_at_deq.state.ms.us wrote in
> news:ihaci0pkeuhsumhgdv3qo7uibim8krmpbo_at_4ax.com:
>
>

>>The instances are configured pretty much the same. 

>
>
> What version of Solaris?
> Which version of Oracle DB?
>
> CBO or RBO?
>
> I bet if you make EXACTLY the same you would see no performance difference.
>
> What about the data in these 3 DBs?
> Same amount?
> All data recently ANALYZEd?
>
> What does the EXPLAIN PLAN show for each DB?

What is the memory configuration on each box? (Odds are the multi-proc boxes have more than the single proc).

CBO can change depending on how much memory is available for sorting, even if everything else is the same.

Is system swap space configured correctly? (typically three to four times physical memory?) Maybe there is some kind of thrashing at the Unix level causing your problem.

--Mark Bole Received on Wed Aug 25 2004 - 04:57:24 CDT