Re: system performance

This gets much more complicated than we've stated so far. The key part of what
I was saying is "index if it has select/omit".
All of this will be dependent upon

What release and ptf level
The QAQQINI settings (ignore_derived_index)
Any other indexes built (not logicals, but sql indexes).

Recent thread all about QAQQINI is worth reading.
Jim Franz


----- Original Message ----- From: "Dennis Lovelady" <iseries@xxxxxxxxxxxx>
To: "'RPG programming on the IBM i / System i'" <rpg400-l@xxxxxxxxxxxx>
Sent: Saturday, August 29, 2009 12:43 PM
Subject: RE: system performance

If you are doing any SQL or Query, I believe the sql engines will not
use an
index if it has select/omit. That can cause the sql engine to have to
build
it's own index to use.
Jim Franz

Sorry, Jim, that's incorrect. The SQL engine will use indexes for the WHERE
clause. I cannot speak for QUERY, but OPNQRYF also uses any index for the
WHERE clause.

Dennis

--
This is the RPG programming on the IBM i / System i (RPG400-L) mailing list
To post a message email: RPG400-L@xxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit: http://lists.midrange.com/mailman/listinfo/rpg400-l
or email: RPG400-L-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
at http://archive.midrange.com/rpg400-l.