Date:         Sun, 13 May 2001 15:36:33 +0000
Reply-To:     Puddin' Man <pudding_man@POSTMARK.NET>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         Puddin' Man <pudding_man@POSTMARK.NET>
Subject:      Re: Improve performance through  physical placement of indexes?
Comments: To: Jay Stevens <jay@WHITEHURST-ASSOCIATES.COM>
Content-Type: text/plain; charset="iso-8859-1"

Three questions re SPDS (just curious):

 1.) At what cost (license and otherwise)?

 2.) On what platform(s)?

 3.) Have you actually _used_ SPDS to get SAS to
     store/use an index on one device with the
     dataset stored on another? Got an example
     of code that accomplishes this??

  Skoal,
  Puddin'

*******************************************************
*** Puddin' Man     *** Pudding_Man@postmark.net  *****
******************************************************;


Jay Stevens wrote:

> SAS Scalable Performance Data Server allows you to place Datafiles,
> Index files, and Metadata files on completely separate/independent
> drives/volumes.... and yes, it does dramatically increase performance
> when using the index.
>
> Jay L. Stevens
> Whitehurst Associates, Inc.
> http://www.whitehurst-associates.com
>
>
> On 11 May 01 16:16:39 GMT, pudding_man@POSTMARK.NET (Puddin' Man)
> wrote:
>
> >Lewis, Dan BGI SF wrote:
> >
> >> I'd like to improve the performance of a WHERE clause that uses an
index.
> >In
> >> the ancient olden days I could sometimes get dramatic performance
> >> improvement by putting the index of a (non-SAS) file on a physically
> >> separate drive from the data portion of the file. This could result in
huge
> >> performance improvements because it reduced the movement of the disk
heads.
> >
> >This is a good example of "thinking hardware" (to improve
> >performance) on the part of the poster. Most commendable ...
> >
> >> I wonder if I can do the same thing with SAS indexes under the Solaris
OS?
> >
> >I can't say for sure, but everything I've seen _suggests_
> >that SAS won't let you do this.
> >
> >You've had several potentially helpful responses.
> >
> >I'll only add that the onliest thing better than storing
> >the index in memory is maybe storing both the index _and_
> >the data in memory.
> >
> >If you are running SAS 8.1 or higher, I _think_ you
> >_may_ be able to use the SASFILE statement, which is
> >designed to load an entire SAS dataset into memory
> >(if it's not too large).
> >
> >I ran a simple test with Win2k/8.1: SASFILE _appears_
> >to make proper use of the index _and_ dataset in
> >memory. "Quite speedy", it was.
> >
> >Of course, you wouldn't wanna use SASFILE where the size
> >of the index + dataset exceeds available physical memory.
> >
> >Just another possibility ...
> >
> >  Zalut,
> >  Puddin'
> >
> >*******************************************************
> >*** Puddin' Man     *** Pudding_Man@postmark.net  *****
> >******************************************************;
> >
> >"Rob the average man of his life illusion and you
> > rob him of his happiness at the same stroke."
> >     - from "The Wild Duck", Henrik Ibsen, around 1885