RE: unexplained performance problems with SQL after upgrading to V5R4

More queries are going down SQE query engine, which may mean that you have
to do some additional database and SQL performance tuning with that query
engine in mind.
Keep in mind that with the new OS, all access plans on the systems are
recreated. Most for the better, but some for the worse (temporarily
anyway).
Building 'perfect' SQL indexes will do wonders for your database query
access. And it's not just set it and forget it type of activity. As you've
found, things change (i.e. the OS upgrade) and you have to revisit your
indexing strategy.

Elvis

Celebrating 11-Years of SQL Performance Excellence on IBM i, i5/OS and
OS/400
www.centerfieldtechnology.com


-----Original Message-----
Subject: unexplained performance problems with SQL after upgrading to V5R4

Hi, all:

One of our large customers upgraded their production system from V5R3 to
V5R4 last week-end.

They re-initialized all of their DASD and re-loaded all of their data
from back-up tapes, during or after the upgrade to V5R4. They say access
paths were saved (and restored), so they are not seeing index rebuilds
going on.

The problem is, for their applications that use embedded SQL, they are
seeing much slower performance, versus what they saw a week ago, when
they were still running on V5R3.

Does anyone have any ideas about where to look, or what to look for?
Perhaps some values changed in QAQQINI?

Thanks in advance for any suggestions, hints or tips.

Regards,

Mark S. Waterbury