I still do that all the time in heavy SQL environments where auto tune is
not a good thing.
Why? Every time auto tune changes the environment, SQL is forced to
re-optimize every query. Sometimes that optimization is not optimal, versus
what it was before, and performance issues start to crop up. So to allow
SQL to optimize a query only one time, we turn off auto tune, and then let
it run. Then we run the Day/Night changes as needed.
--
Jim Oberholtzer
Agile Technology Architects
-----Original Message-----
From: MIDRANGE-L [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Rob
Berendt
Sent: Friday, December 15, 2017 9:47 AM
To: Midrange Systems Technical Discussion <midrange-l@xxxxxxxxxxxx>
Subject: RE: Subsystem and memory pools
There are others who spend more time in this stuff...
Back when we had AS400's we used to have two job schedule entries. NIGHT
and DAY. These basically changed the pool sizes to change the optimization
between interactive and batch.
Rob Berendt
--
IBM Certified System Administrator - IBM i 6.1 Group Dekko Dept 1600 Mail
to: 2505 Dekko Drive
Garrett, IN 46738
Ship to: Dock 108
6928N 400E
Kendallville, IN 46755
http://www.dekko.com
From: "Steinmetz, Paul" <PSteinmetz@xxxxxxxxxx>
To: "'Midrange Systems Technical Discussion'"
<midrange-l@xxxxxxxxxxxx>
Date: 12/15/2017 10:40 AM
Subject: RE: Subsystem and memory pools
Sent by: "MIDRANGE-L" <midrange-l-bounces@xxxxxxxxxxxx>
I'm a firm believer in auto adjustment. QPFRADJ = 2.
Agree, memory is moved in small chucks, little at a time, which sometimes
is bad.
Also a firm believer in a fewer number of pools, I only have 5.
My paging numbers (from MPG) are good, so I feel the configuration is
good.
Majority of our batch work runs off shift, after 5, before 8, *SHRPOOL1.
If no batch work is running, that memory is released back to *BASE, which
then in turn is available for *INTERACT.
From 8 to 5, *INTERACT for 5250 takes the memory from *BASE, as needed.
These rules have been in place for decades.
But now we have more background jobs, (IVR, Interfaces, Credit Card
system, DOMO Replication, Halcyon monitoring, Robot Scheduler), that are
constantly running, serving both batch and/or interactive.
How should these be considered,
batch-*SHRPOOL1
interactive-*INTERACT
or leave in *BASE.
Paul
-----Original Message-----
From: MIDRANGE-L [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Rob
Berendt
Sent: Friday, December 15, 2017 10:17 AM
To: Midrange Systems Technical Discussion
Subject: Re: Subsystem and memory pools
The classic answer "it depends".
Do you have auto adjustment set on your pools? Some argue that it's a
good thing, why waste memory in a pool that's currently under utilized.
Some might argue that IBM's auto adjuster is not robust enough and
cautiously only moves small chunks at a time.
Some might argue that changing your pool sizes too often forces the query
optimizer to notice the environment changed and reoptimize your queries.
Some might say that if you're going to do this they you really need to
look at
WRKSHRPOOL
F11=Display tuning data
and set a minimum size to keep others from stealing too much from a
pool.
Where do activities fall in priority? For example, are you still using a
bunch of 5250 applications? Should they get priority over the
application? Do you lump 5250 in with "interactive" work performed by the
application?
Are there other tuning considerations which may cause consideration to
other pools? For example, fixed vs calc paging, max active, faulting
settings, etc.
Rob Berendt
--
IBM Certified System Administrator - IBM i 6.1 Group Dekko Dept 1600 Mail
to: 2505 Dekko Drive
Garrett, IN 46738
Ship to: Dock 108
6928N 400E
Kendallville, IN 46755
http://www.dekko.com
From: "Steinmetz, Paul" <PSteinmetz@xxxxxxxxxx>
To: "'Midrange Systems Technical Discussion'"
<midrange-l@xxxxxxxxxxxx>
Date: 12/15/2017 10:03 AM
Subject: Subsystem and memory pools
Sent by: "MIDRANGE-L" <midrange-l-bounces@xxxxxxxxxxxx>
Reviewing some subsystems that were created by 3rd party applications.
By default, they run system pool 2, *BASE.
Normally I have *BASE for system usage only.
All my interactive work runs in system pool 4, *INTERACT.
All my batch work run in system pool 5, *SHRPOOL1
3rd party applications, which are constantly running, where should they
reside, *INTERACT or *SHRPOOL1?
System Pool Reserved Max
Pool Size (M) Size (M) Active Pool
1 17344.7 2872.0 +++++ *MACHINE
2 65406.2 14.5 1346 *BASE
3 1576.7 2.5 51 *SPOOL
4 30376.1 .1 3141 *INTERACT
5 42975.9 <.1 30 *SHRPOOL1
Thank You
_____
Paul Steinmetz
IBM i Systems Administrator
Pencor Services, Inc.
462 Delaware Ave
Palmerton Pa 18071
610-826-9117 work
610-826-9188 fax
610-349-0913 cell
610-377-6012 home
psteinmetz@xxxxxxxxxx
http://www.pencor.com/
midrange.com
