RE: EVI (encoded vector index) question

Michael,

As always, the answer is it depends....

How many EVIs and what's the data like in the columns with the EVIs.

I've used EVIs, before but always just created them once.

Technically, IBM recommends dropping all indexes/logical files before a large data load.

You may just want to run a test.

Do the load without the EVIs.
See how long it tales to create them.

Do the load again with the EVIs already existing.


HTH,
Charles

-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx [mailto:midrange-l-
bounces@xxxxxxxxxxxx] On Behalf Of Michael_Schutte@xxxxxxxxxxxx
Sent: Friday, January 11, 2008 4:44 PM
To: midrange-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=/rza
jq/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 (at night) I wouldn't think would be an excessive
amount of activity. What do you think?

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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