Jeffrey,

In Unidata, I think so.

In Universe the answer is yes.

Actually this is one of the two benefits, the other is selecting a set of ids 
for a given index value.

For example, if you have a CUSTOMER file with the ZIP (postal) code indexed 
then this statement will give you all of your customers sorted by ZIP code and 
@ID: 
SELECT CUSTOMER BY ZIP
and it will be quick.
 

Don




On Thursday, March 13, 2014 2:26 PM, Dave Laansma <dlaan...@hubbardsupply.com> 
wrote:
 
I do not believe so. I believe an index is only used during the SELECT 
statement and then only when the indexed field is the only field in the select 
criteria.

So, if practical, use the indexed field in the first selection of the file, 
then all records will be in sorted order of the indexed field. Then narrow that 
list down by other, non-indexed fields.

Sincerely,
David Laansma
Hubbard Supply Co.
Direct: 810-342-7143
Office: 810-234-8681
Fax: 810-234-6142
www.hubbardsupply.com
"Delivering Products, Services and Innovative Solutions"

-----Original Message-----
From: u2-users-boun...@listserver.u2ug.org 
[mailto:u2-users-boun...@listserver.u2ug.org] On Behalf Of Dave Davis
Sent: Thursday, March 13, 2014 2:19 PM
To: U2 Users List
Subject: Re: [U2] unidata index

Don't know - I wouldn't index a field for that reason alone.

And it probably wouldn't help if you had other fields you were sorting by, or 
other fields you were selecting, in the same select statement.

-----Original Message-----
From: u2-users-boun...@listserver.u2ug.org 
[mailto:u2-users-boun...@listserver.u2ug.org] On Behalf Of Jeffrey Butera
Sent: Thursday, March 13, 2014 2:15 PM
To: U2 Users List
Subject: [U2] unidata index

Stupid index question: does indexing a field help performance when sorting BY 
that field but it's not otherwise involved in the query?

--
Jeffrey Butera, PhD
Associate Director for Applications and Web Services Information Technology 
Hampshire College
413-559-5556

http://www.hampshire.edu
http://www.facebook.com/hampshirecollegeit

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