Dawn May has written some interesting blogs on this subject
From: "Lowary, Jim" <jlowary@xxxxxxxx>
Sent: Wednesday, September 5, 2012 7:14 AM
Subject: Performance tuning
We are a v6.1 and it's been a long time since I was into performance
tuning so I just wanted check on this.
Right now our system has a # of jobs in system of 12,033 yesterday it
was 13,345. It used to be in days of long ago (if I remember correctly)
that QTOTJOB and QADLTOTJ had an effect on performance when their table
had to be expanded. Our values are QTOTJOB = 3250 and QADLTOTJ = 200
with our QACTJOB = 700 and QADLACTJ = 50 and the active # of job
bouncing around 1200 to 1300.
My question is are these values as important as I think I remember them
being? Long time ago when I was heavy into tuning the system could come
to a halt for a few seconds while it expanded these tables and until
that happened no new jobs would start and ones running we adversely
effect. Does that still hold true?
Given what I'm seeing on this system, if I was using my old rule of
thumb I would be setting these to around QTOTJOB = 13000 and QADLTOTJ
= 500 and QACTJOB = 1300 and QADLACTJ = 100, just as a rough guess.
Do these values come into play as much as they use to? I'm going back
to getting the last drop of oomph! out of a B70, so I know the playing
field has changed tremendously, and I've been working in programming
side since then.
Thanks for any suggestions,
-- Jim Lowary