RE: SQL RAND function question

Hi Charles

The word "granularity" comes to mind - if multiplying and rounding, the evenness might be compromised. But I would still expect each bucket to have about the same number or elements, given enough iterations.

I've not been completely happy with the SQL RAND() function, but maybe I did something to affect it. All these things ARE pseudo-random, after all, and the algorithm can make a big difference. But now I speak with less than exhaustive experience. ;-)

Regards
Vern

At 07:19 AM 2/13/2008, you wrote:

Probably should have said, "by definition random numbers should be evenly distributed".

The RAND() function does AFAIK provide an even distribution from [0,1]. The problem is what happens
when you multiply that by N.


Charles Wilt
Software Engineer
CINTAS Corporation - IT 92B
513.701.1307

wiltc@xxxxxxxxxx


> -----Original Message-----
> From: midrange-l-bounces@xxxxxxxxxxxx [mailto:midrange-l-
> bounces@xxxxxxxxxxxx] On Behalf Of Wilt, Charles
> Sent: Wednesday, February 13, 2008 8:15 AM
> To: Midrange Systems Technical Discussion
> Subject: RE: SQL RAND function question
>
> Loyd,
>
> Yes it does. BUT if you call it 1000's of times, it doesn't given you an
> even distribution of numbers
> between 0-11.
>
> By definition, RAND() should given an even distribution.
>
> Charles Wilt
> Software Engineer
> CINTAS Corporation - IT 92B
> 513.701.1307
>
> wiltc@xxxxxxxxxx
>
>