RE: Using an SQL index over DDS file? -- MIDRANGE-L

Subject: RE: Using an SQL index over DDS file?
From: "DeLong, Eric" <EDeLong@xxxxxxxxxxxxxxx>
Date: Mon, 26 Jul 2010 16:01:10 -0500
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Loyd,

DISTINCT is a post result set operation. The initial result set is
created, then DISTINCT eliminates duplicate rows from that result set.
I doubt if it factors into the access plan...

-Eric DeLong

-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Loyd Goodbar
Sent: Monday, July 26, 2010 3:20 PM
To: Midrange Systems Technical Discussion
Subject: Re: Using an SQL index over DDS file?

Success!

Apparently DISTINCT and GROUP BY indeed act differently under the
covers,
because DISTINCT took ~60-90 seconds while GROUP BY was 100ms. VE
reports
using an index scan with the new index. Perhaps DISTINCT does not take
advantage of indexes? It seems unlikely.

Thanks everyone for the help and suggestions!

--Loyd

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