Re: Performance problem?

what kind of activity are you showing on the other hard drives ?

there are oracle background processes other than DBWR that also perform write operations, like LGWR and ARCH.

one key to tuning disk performance is understanding the nature of the i/o activity, and effectively distributing that i/o load across multiple hard disks, preferrably on multiple controllers.

the disk device vendor should be able to provide you with specs.

"Little Prince" <milan1810_at_geocities.com> wrote in message news:9ir6ek$h5322_at_ctmsun0.macau.ctm.net...
> I meet a problem recently. I use Oracle ver. 8.0.6 and IBM RS6000 (AIX)
 v.4.
> The performanc of my oracle server sometimes is very poor. At that time, I
> querey 'SELECT * FROM V$SESSION_WAIT'. I have started three DBWR. I found
> that there are three 'DBWR PARALLEL WRITE' and several 'WRITE COMPLETE
> WAITS' events. These events continuously appear in V$SESSION_WAIT. Then, I
> use UNIX command 'iostat /hdisk1' to check the hard disk. The % activity
 if
> 98%, 99%, 100%, etc. But, only several transactions are existed at that
> time.
>
> I made a conclusion that the poor performance may be due to IO bound
> because Oracle may continuously write data from buffer pool to data files
 on
> disk. How can I tune the Oracle server? How can I know the throughput of
> harddisk1?
>
> Anyone can give me a comment?
>
> Regards,
> Andrew
>
>
>
Received on Sun Jul 15 2001 - 00:32:55 CDT