Date: Mon, 10 Apr 2006 14:45:54 -0400
Reply-To: "Fehd, Ronald J" <rjf2@CDC.GOV>
Sender: "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From: "Fehd, Ronald J" <rjf2@CDC.GOV>
Subject: Re: Efficiency of Proc sort with out =
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> From: Sarah Gollin
> Just trying to settle an argument. My colleague believes
> that it is more
that depends on your definition of 'efficient'
> to use an out = statement on a proc sort as opposed to
> overwriting the original dataset. I have googled this but
> have been unable
> to come up with a definite answer. Can you help?
generally it is Highly Recommended
to -always- use an out= for proc Sort,
most especially when you are reading
from a two-level data set name
for a one-level name: i.e. work.DataX
then it is not definite.
Using out= leaves your data= data set
in its original order
and, of course, then you have a/your copy
in the order of the by variables.
you might want to subset as you sort:
PROC Sort data = Lib.X(keep = ...
where = (...))
out = Y;
which would be another reason
that this topic would discussed under efficiency.
Ron Fehd the optimization
or macro maven CDC Atlanta GA USA RJF2 at cdc dot gov