Re: Oracle 8 Tuning Question

>>
>>I am fairly new to the Oracle game and I'm having a tuning problem. I am
>>running a query on a fairly large table (1M records) and it seems to be
>>taking much longer than it should. I'm running Oracle 8 on and NT4.0
>Server
>>box. What I've noticed is when the query is being executed, the total CPU
>>usage rarely (if ever) goes above around 16-18% and never above 25%, but,
>>the query can take several minutes (3-10 minutes depending on result set)
>to
>>execute. Why would the CPU usage remain so low? Why not use all of the
>CPU
>>time? The box has no other tasks running simultaneously that should
>prevent
>>it from taking what it needs.
>>
>>I believe that I have all of the tables indexed properly and the query is
>>optimized, but, like I said, I'm new enough to not be 100% sure.
>>
>>Any suggestions on this would be greatly appreciated.
>>
>>Doug
>>
>>dpeel_at_mindspring.com
>>

Doug, presumably, you are using NTs Performance monitor to determine the CPU usage, As Brian said, you are probably IO bound. This can be due to no appropriate index (use explain plan to check this out), or simply slow disk drives. If you go into performance monitor, you can monitor the disk activity. However, you need to go to a command prompt window and run the the command DISKPERF (I think..maybe DISKMON....). Then after you reboot the server, you can collect disk performance info. I have found Bytes Written and Bytes Read to be the most useful. On occasion, I have also looked at %Drive busy.

Hope these hints help a little...

Dan Hekimian-Williams Received on Tue Jun 08 1999 - 03:22:24 CEST