Date:         Tue, 17 Dec 1996 15:15:15 PST
Reply-To:     Melvin Klassen <KLASSEN@UVVM.UVIC.CA>
Sender:       "SAS(r) Discussion" <SAS-L@UGA.CC.UGA.EDU>
From:         Melvin Klassen <KLASSEN@UVVM.UVIC.CA>
Subject:      Re: Sorting huge datasets: SAS 6.08 under wfwg.

jk93 <jk93@EROLS.COM> writes:
>I'm using SAS 6.08 (wfwg3.11). I'm sorting huge datasets (almost 2 million
>cases, 30 variables), though only sorting on one variable (like ID), using
>Proc Sort. But it seems that SAS makes NO use at all of extended memory when
>sorting. I have 32 meg (with an 8 meg vcache), but the disk is just
>constantly crunching (heavily) during the sort. (I'm wondering, also, how bad
>this is for the disk, during these hour-long sorts). But even with much
>smaller datasets, the disk acts the same way, with seemingly no use of
>memory. Any ideas?
 
Buy more RAM.  How much?
 
Assuming you have 8 bytes per variable, and 30 variables, and 2 million cases,
and you are sorting on 1 variable, you will need at least:
 
     (30*8 + 1*8) * 2 million
 
i.e., 496 million bytes of RAM, to store your file.
 
About 500MB of RAM will only cost about $5,000. -- assuming that you have
enough empty SIMM-slots on the computer's motherboard to hold the RAM.
 
It might be easier/cheaper/quicker to tell SAS to "index" the dataset,
and then use the index to access the cases.