Re: performance problems

Georg Walk was kind enough to write:
> We have performance problems with a complex system. We use a compaq proliant
> double-processor with a Raid-5 System and Win2000 as database server, 3
> Citrix-server and about 90 clients. The problem is a little bit curious. We
> have some days without problems and than some days we have performance
> problems between 20 minutes and sometimes the hole day is bad.
> We cannot determine any simular situation. The only point is that it looks
> like the applications are waiting for response of the database-server. But
> when we looking to the database server we cannot see more as 30 % of used
> memory and 30% productivity of the main.processors.
>
> Some ideas are welcome
>

It could be many, many things -- intermittent network "storms" caused by periodic, heavy network usage; portions of O/S memory being swapped or paged too often; a RAID member being "weak" and needing periodic refreshes; a slow archiver that can't keep up with log writer; redo logs filling up and not being archived before the cycle comes back around; a Denial of Service attack against your servers; or a host of other problems.

Have you referred to any Oracle performance tuning manuals such as those in the doc set? Have you turned on any monitoring tools to gather db or O/S or network statistics over time (instead of trying to catch the culprit in the act)? Have you checked for errors or strange entries in your Oracle or Windows logs? Do you use shared or dedicated servers?

In fact, please give a few more details about what you have already tried ... for instance, to determine that you are only using a third of your available resources. And while you're at it, don't forget to mention your Oracle version (thanks for including O/S info).

-- 
:%s/Karsten Farrell/Oracle DBA/g