RE: SMP experiences

["Elvis Budimlic" <ebudimlic@xxxxxxxxxxxxxxxxxxxxxxxxx>]

Rick,

SMP will help Query Optimizer a great deal so if you are using lots of
SQL or OPNQRYF in your processing, you should see a notable performance
improvement. 
On the native I/O side of things, the only benefit I could think of with
SMP is parallel index maintenance, which in itself may give you a boost
in performance if your processing is update intensive and you have a lot
of indexes (LFs) being maintained. 

As for drawbacks, the only one I heard a customer mention is the
aggressive utilization of system resources.  What I mean is, if you have
some really intensive query app, optimizer will try to use 100% of CPU
to fulfill its requests, which may slow down your interactive
throughput.  It doesn't sound like that would be a problem on your
system though, as you say you have 16 processors and you plan to use SMP
to help nightly batch processing.  And even if it was a problem, there
are ways (and products) that can help you deal with resource allocation
management.
Another thing that you'll notice jump up is disk arm utilization, but
that's what you want to see as that'll help performance as well.

<VENDOR ON>
If you are narrowly focused on helping the nightly batch processing,
company I work for has a product we are about to GA, batch/Accelerator.
If your job is I/O bound and works on database files, this product is
likely to bring down the elapse time of your batch job.
 
http://www.centerfieldtechnology.com/tools/batchaccelerator.asp

<VENDOR OFF>

Elvis

-----Original Message-----
 
I am looking at our use (or lack of use) of Symmetric Multiprocessing on
our
production iSeries.  Specifically I am researching how SMP may be used
to
improve our nightly batch processing.  We have an 8xx with 16
processors.