Date:         Fri, 7 Nov 2008 11:23:54 -0500
Reply-To:     "Lane, Jim" <jim.lane@RBC.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         "Lane, Jim" <jim.lane@RBC.COM>
Subject:      Re: what is the most effective way to remove observation with
              duplicate key?
Comments: To: kwu0914 <kwu0914@GMAIL.COM>
In-Reply-To:  A<gf1jh6$5fo$1@aioe.org>
Content-Type: text/plain; charset="iso-8859-1"

Kevin: I'm not sure that it's logically possible to remove duplicates
without sorting data somewhere along the line. You can use SELECT
DISTINCT in PROC SQL but that will sort the data under the covers if it
isn't sorted already. If you try to use SET BY and FIRST.key in a DATA
step SAS will require you to have the data sorted beforehand.

In general sorting is either expensive or inexpensive depending on how
much data you have. Sometimes it's just a cost of doing business.

FWIW

Jim Lane

-----Original Message-----
From: SAS(r) Discussion [mailto:SAS-L@LISTSERV.UGA.EDU] On Behalf Of
kwu0914
Sent: 2008, November, 07 9:32 AM
To: SAS-L@LISTSERV.UGA.EDU
Subject: what is the most effective way to remove observation with
duplicate key?

All SAS_L users, what is your commom way to do that?
Is there a effective way without requiring sorting to do it since we all
konw sorting is a expensive operation?

or can you refer any paper which is foucs on this aspect?

Thanks!

Kevin
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