Date:         Wed, 18 Dec 2002 17:08:13 -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: is there a way to compress indexes in SAS? are theyever
              compressed?
Content-type: text/plain; charset=us-ascii

Jack Hamilton <JackHamilton@firsthealth.com> replied:
> Why would the index have to be rebuilt regularly?  Does SAS not
> rebalance the index tree when it updates the data set?

I'm sorry.  I didn't state my point well.  I mean that
under many circumstances, such as appending new records to a
data set, or updating the data set (when the values of the
index fields get changed), it may be significantly faster to:

1) delete the index;
2) perform the data set manipulations; and
3) re-build the index.

So, if the index was going to have to be re-built anyway, saving
the old index and trying to compress it might not be optimal...

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