Re: Embedded SQL Logical file use -- RPG400-L

I spoke to the DB2 developers at Common on this specific question.
The use of a logical file in a select in a sqlrpgle will cause the "classic"

sql optimizer to evaluate that logical first, but the optimizer may or maynot select that view.I have been able to demonstrate at v5r3 that in one instance, using thelogical in a select

did greatly boost performance. Logical did not have select/omit criteria.

Check the use of the QAQQINI query options to see if anything fits yourneeds. I have

not explored this, but it was a recommendation from the developers.

For another thread - some very interesting new performance features inv5r4....


Jim Franz

----- Original Message -----From: "Mark Allen" <scprideandms@xxxxxxxxx>

To: "RPG programming on the AS400 / iSeries" <rpg400-l@xxxxxxxxxxxx>
Sent: Thursday, March 30, 2006 8:27 AM
Subject: Re: Embedded SQL Logical file use

check the archives , seems there weas a discussion while back on a setting
for the Optimizer to "fix" this?

On 3/29/06, Kyle Collie <kcollie@xxxxxxxxx> wrote:


We have an SQLRPG module that is opening a cursor based on a S/O
logical. Everytime the program is run the query optimizer is checking
for a better file to use and is eventually just coming back and using
the initial S/O logical that we specified in the select statement. Is
there a way to force the logical and prevent that processing time that
is wasted when it tries to find a better index?

The time it takes up is about 1 minute 20 seconds.

Thanks in advance,

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