Re: Enterprise slow, Standard fast?

From: Arska <NaruArska_at_hotmail.com>
Date: Mon, 08 Nov 2004 08:45:25 +0200
Message-ID: <cmn4m4$h89$1@plaza.suomi.net>

Mladen Gogala wrote:
> On Sun, 07 Nov 2004 20:38:32 +0200, Arska wrote:
>
>

>>Now we need to tune every job again, parallel execution in mind. Or deny
>>parallel execution for these jobs. (How?)

>
>
> No! You should just tune the buffer cache hit ratio. When it is close to
> 100%, your performance is good. Make sure that BCHR reports are compiled
> and run every morning. The job of a DBA is to maintain the highest cache
> hit ratio possible. DBAs are the priests of the buffer cache god. You
> shouldn't be tuning applications, but the instance. Users are not running
> applications, they're running instance, so that's what you tune. That
> means that all you have to do is to fiddle and twist the buffer cache
> parameters and everything will be good. Make sure that 99% of cache hit
> ratio is entered into the official company documentation as the ultimate
> performance metrics.
>

Buffer cache is currently 1008 MB, and cache hit ratio is 98.9% after running few heavy update jobs. Are you saying I need to buy more RAM and increase buffer cache? I dont think so.
We only need to add "ALTER SESSION DISABLE PARALLEL QUERY" to all jobs, which was slow with EE, and magically they are fast again.

Parallel query does add some overhead. Usually it is still faster, but not always. In this case it is better not to use it. Received on Mon Nov 08 2004 - 00:45:25 CST