Michael,
As I understand EVI's, they are generating a lot of statistical
information about the data in your file so the optimizer can make better
decisions. Even down to how many occurrences of a field value there are
in the file. Based on that it kind of makes sense that there might be a
performance hit of some kind if the table is updated frequently.
You might try posting to the midrange list. A lot of SQL threads happen
there.
Rick
-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx
[mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of
Michael_Schutte@xxxxxxxxxxxx
Sent: Friday, January 11, 2008 2:35 PM
To: rpg400-l@xxxxxxxxxxxx
Subject: EVI (encoded vector index) question
Anybody experienced in creating EVIs (encoded vector index)? I'm
reading the IBM help site but I have a couple of questions.
http://publib.boulder.ibm.com/infocenter/iseries/v5r4/index.jsp?topic=/r
zajq/whatareevi.htm
I have a new table that's going to have records added to it monthly.
The IBM site says to create EVIs on Read-only tables or tables with
minimum of INSERT, UPDATE, DELETE activity.
Once a month activity I wouldn't think would be an excessive amount of
activity. What do you thing?
If you agree with me, the site also states When Loading Data...
1. Drop EVIs, load data, create EVIs.
Is that true? It sounds like to me that before the monthly updating...
I'll need to drop the EVIs, then add my new records... then recreate the
EVIs.
That kinda sounds right, but also it doesn't. It sounds right so that
the information can be regathered. but then again, shouldn't that happen
on it's own?
If I have to drop the EVIs and recreate then I'm not going to be able to
do this. All though this table is only going to add new monthly records
every month, it's going to contain a lot of records. I'm not sure if we
can afford to have the recreation to run every month.
Any help will be appreciated.
Michael Schutte
Admin Professional
Bob Evans Farms, Inc.
"The Secret's the Sauce! Enjoy our new Bob-B-Q Pulled Pork Knife & Fork
Sandwich!"
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