RE: DB2 Symmetric Multiprocessing (option 26 of 5770SS1) Was: Performance tuning

Rob,

< IBM's tool only readjusts small chunks at a time, spread out over quite
some time period. Which may not be near responsive enough if you've just
dropped QINTER to start your month end, as just one example.

I've seen this behavior, which is not always satisfactory.
IBM auto tune adjusts approximately every 20 seconds, approximately 5k chunks.
What do you recommend?
What are some alternatives?

Paul


-----Original Message-----
From: MIDRANGE-L [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Rob Berendt
Sent: Monday, December 03, 2018 1:24 PM
To: Midrange Systems Technical Discussion
Subject: RE: DB2 Symmetric Multiprocessing (option 26 of 5770SS1) Was: Performance tuning

There are a few of schools of thought on auto tuning.
One is that, in a 'more than light' SQL shop one should not use autotuning
as it forces the sql optimizer to recalculate.
Another is that auto tune at IPL time may be appropriate, to start taking
advantage of new memory added to the system.
Another is that a light to no sql shop could use IBM's autotuning and be
happy.
Another is that IBM's autotuning is too gradual and one should use a more
responsive 3rd party product.

IBM's tool only readjusts small chunks at a time, spread out over quite
some time period. Which may not be near responsive enough if you've just
dropped QINTER to start your month end, as just one example.


Rob Berendt