Re: Oracle performance issue

On Tuesday 02 October 2001 22:59, Mauro Minomizaki wrote:

> Hi there,
> It is my first post here, and I hope I'm posting this message in the
> right forum.
> I have an IBM AIX server machine running Oracle 8.0.6.3 and AIX
> 4.3.3-ML08 update.
> When running several select count(*) in parallel I noticed a
> performance degradation that is pretty unusual.
> Taking a look at the processes table, I see that asynchronous I/O
> servers (aioserver) are consuming all CPU available on this server
> (12-way SMP) and the strange thing is that there is very little I/O
> really running to the disks.
> I am sysadmin of this server, so, I have very little knowledge in DB
> performance side. But, I have already done some AIX tuning in
> aioserver and vmtune that improved some performance.
> Does anyone have any hint or suggestion to make in order to improve
> select performance?
> Just one more question, I know that this Oracle version is a little
> old, upgrading it to 8.1.7 or 9i will improve performance as well?
> Thank you for your attention!

Well, you have told us virtually nothing about your environment, so all I can give is a general response.

According to IBM, 80% of a database's performance is determined by the database design and the application programming.

Of the remaining 20%, the factors affecting performance are machine memory, Oracle SGA size, aio configuration, disk speed, channel speed, and processor speed.

If you want to share some more info with us, maybe we can offer more practical suggestions based on your configuration.

I would recommend upgrading to 8.1.7. There have been significant improvements with how Oracle uses aio servers under AIX in the last few releases. Received on Tue Oct 02 2001 - 18:27:46 CDT