RE: Same query runs slowly after 4.3 - 4.5 upgrade

I am not sure if this is what is causing you the problem or not, but it
might be worth looking into.  We use JDEdwards software and after going to
4.5 we had a lot of jobs run longer than they did before.  JDE and IBM both
said it is due to the query optimizer and IBM changing the access path size
for all files to be *max1tb.  It was suggested that we change all of our
files to be the *max1tb.  Apparently all files associated with each of the
files you are using need to be the same access path size of *max1tb.  If the
query needs to create an access path on the fly as a temporary file, it will
create it as the *max1tb.  I would look at changing the PF's you are using
and all of the logicals associated with these PF's to be *max1tb and then
try running the query. The only other thing would be to try and build
logical files that would be the same access path or keys as the query would
need, so the optimizer would not have to try and create one on it's own.

Jim Rubino



-----Original Message-----
From: chrisw@bluechip.co.uk [mailto:chrisw@bluechip.co.uk]
Sent: Thursday, December 12, 2002 3:23 AM
To: midrange-l@midrange.com
Subject: Same query runs slowly after 4.3 - 4.5 upgrade


Hello All,

We have a QM query which runs over 2 files and uses the group function and
concatenates fields etc, this query takes about 40 minutes to run under
4.3, after upgrading to 4.5 recently the query takes about 20 hours.
We have loaded the last database group package (number 12)

I have been trying to create logical files and the debug messages suggest
that they are being used although this hasn't improved the query time .

Has anyone else had similar problems and what did you do to overcome them?

Regards,
       Chris Walton

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