RE: Excessive library cache latch contention

Neil,

A followup on JL's indication of CPU usage. You can use the following script on most *nix platforms to determine the top CPU consumers - either across all processes, as well as for a specific string such as a DB SID ($1).

#!/bin/ksh
uptime
echo "PID %CPU RUSER CPUTIME ELAPSED COMMAND" if [ $# == 1 ]; then

        ps -eo pid,pcpu,ruser,time,etime,args | grep $1 | sort -nr +1 | head -20 | awk '{print substr($0,1,80)}' else

        ps -eo pid,pcpu,ruser,time,etime,args | sort -nr +1 | head -20 | awk '{print substr($0,1,80)}'
fi

The interesting aside is that you can quickly identify a CPU-hungry process by comparing the CPUTIME and ELAPSED time - if they are close, you have found a possible culprit. Remember that the 'get-miss-spin-sleep' cycle is going to consume a lot of CPU in the spin phase. If you aren't able to fix the Forms, then you could alleviate the pain little bit by reducing the _spin_count. (I had tried this in desperation on a Sequent box many moons ago.) Basically, you are facilitating more CPU bandwidth at the risk of inducing more occurences of sleep for 'bad' sessions, and that may be good overall as this might help in reducing the 'waits holding' occurrences. I believe this parameter has been obsoleted in the later versions, but I am suggesting this as you did not mention a specific version.

As ever, YMMV!
John Kanagaraj
Oracle Applications DBA
DBSoft Inc
(W): 408-970-7002

What would you see if you were allowed to look back at your life at the end of your journey in this earth?

• The opinions and statements above are entirely my own and not those of my employer or clients **

> -----Original Message-----
> From: Harvey Neil [mailto:Neil.Harvey_at_sx3.com]
> Sent: Friday, January 31, 2003 9:25 AM
> To: Multiple recipients of list ORACLE-L
> Subject: RE: Excessive library cache latch contention
>
>
> Jonathan,
>
> I think you've got a point on all three counts. I am seeing
> an imbalance of

-- 
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-- 
Author: John Kanagaraj
  INET: john.kanagaraj_at_hds.com

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