RE: IO wait

From: DENNIS WILLIAMS <DWILLIAMS_at_LIFETOUCH.COM>
Date: Tue, 23 Jul 2002 11:44:39 -0800
Message-ID: <F001.0049FF21.20020723114439@fatcity.com>

Jack - Is your load process CPU-bound (high CPU utilization), or I/O-bound (high I/O statistics)? My guess is that from waits you want to confirm that I/O is your high wait statistic, to rule out any other problems that may be slowing down your load time. Then you may want to make a list of ideas that may speed your load and benchmark them (run the same load multiple times under the same circumstances) and see what change or combination of changes reduces the load time. Once you have a new approach that is yielding better load performance, you may want to check the wait times again to confirm that another problem isn't slowing your load.

Dennis Williams
DBA
Lifetouch, Inc.
dwilliams_at_lifetouch.com

-----Original Message-----
Sent: Tuesday, July 23, 2002 10:58 AM
To: Multiple recipients of list ORACLE-L

All,

We are tuning a new vital process on our data warehouse, and it is IO intensive - lots of parallel direct reads and writes. During our testing we are driving IO wait to ~60% (per top).

questions:

1. is top a valid measure of IO wait?
2. Is a high io wait an issue to be concerned about?
3. how else can it be accurately measured?
4. How can I link IO wait to what is happening inside the database?

Thanks,

Jack

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Author: Jack Silvey
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Author: DENNIS WILLIAMS
  INET: DWILLIAMS_at_LIFETOUCH.COM

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To REMOVE yourself from this mailing list, send an E-Mail message to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB ORACLE-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing). Received on Tue Jul 23 2002 - 14:44:39 CDT