Date:         Tue, 5 Mar 2002 10:04:59 -0800
Reply-To:     Cassell.David@EPAMAIL.EPA.GOV
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         "David L. Cassell" <Cassell.David@EPAMAIL.EPA.GOV>
Subject:      Re: tip: copy structure
Content-type: text/plain; charset=us-ascii

Tim and Salene <timandsalene@AARTWOLF.COM> wrote:
> I recently noticed in V8 one can set OPTION OBS=0, then use PROC COPY
to
> copy both a dataset structure and any index definitions.  Resetting
> OBS=MAX and appending obs maintains both the structure and the
> indecies.  Oh, indexes.  Anyway, using PROC COPY to copy the index
> definitions as well as the variable definitions has made it much
easier
> to keep test beds in sync with developing code.

Indices.  The plural is due to the Latin origin.  [So what is the
plural of Windex?  codex?  :-]

> Does anyone know, is it still faster to delete the index before
> appending and rebuild it after?

If you're doing multiple appends, you'll probably find that it is
faster to delete the index, do all the appends, and then rebuild the
index (or indices :-).  Your mileage may vary, but with many appends
the non-sequential I/O becomes a bottleneck.  [At least from my tests
on my machines on my datasets.  Maybe you'll see something different
when you try it.]

David
--
David Cassell, CSC
Cassell.David@epa.gov
Senior computing specialist
mathematical statistician