|Date: ||Wed, 4 Apr 2007 16:10:40 -0400|
|Reply-To: ||Michael Raithel <michaelraithel@WESTAT.COM>|
|Sender: ||"SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>|
|From: ||Michael Raithel <michaelraithel@WESTAT.COM>|
|Subject: ||Re: OT: Chance to Make SAS-L History: Did You Know That...|
|Content-Type: ||text/plain; charset="us-ascii"|
Arthur Tabachneck posted the following "did you know that":
> Did you know that: There is something you can do to improve
> the performance of using count(distinct xxxx) in proc sql?
> Came across the following this morning:
Art, well, I for one, _DID_ know about this particular option. IBUFNO
is covered in my award-winning book, The Complete Guide to SAS Indexes,
in Chapter 5, Index-Related Options, The IBUFNO System Option, pp 66 -
67. This option can help PROC SQL-ers as well as DATA steppers. So, I
would urge the SAS index-using public to look at this way-cool option.
Hey, as long as we are at it; check out IBUFSIZE, which sets the size of
the index pages, themselves. Larger index pages allow more index
entries to be transferred per I/O and can reduce the number of levels of
an index. This double-whammy can also be good for performance.
Of course, both of these tools require more computer memory than would
be used with the SAS-supplied defaults, so the usual caveats apply.
Best of luck to you in all of your SAS endeavors!
I hope that this suggestion proves helpful now, and in the future!
Of course, all of these opinions and insights are my own, and do not
reflect those of my organization or my associates. All SAS code and/or
methodologies specified in this posting are for illustrative purposes
only and no warranty is stated or implied as to their accuracy or
applicability. People deciding to use information in this posting do so
at their own risk.
Michael A. Raithel
"The man who wrote the book on performance"
Author: Tuning SAS Applications in the MVS Environment
Author: Tuning SAS Applications in the OS/390 and z/OS Environments,
Author: The Complete Guide to SAS Indexes
Food is an important part of a balanced diet. - Fran Lebowitz