Alan McCollough
Web Programmer
Allaire Certified ColdFusion Developer
Alaska Native Medical Center
> -----Original Message-----
> From: Max Paperno [SMTP:[EMAIL PROTECTED]]
> Sent: Friday, December 15, 2000 1:26 PM
> To: Fusebox
> Subject: Re: inserting your own UUID into a db table
>
>
> Hi Alan,
>
> Wondering if you've considered this... From SQL7 BOL:
>
> "A GUID is a binary number that is guaranteed to be unique" and
Oh yeah, I forgot. This clause, "guaranteed to be unique" is IMHO a
lame and untrue assertion made by UUID fans, of which I am not; although I
do use it in some instances, hence the CF_UUID tag.
Unless there is an international clearinghouse for UUIDs, such as
for MAC addressess or IP addresses, there is no way to assure that a UUID is
in fact unique. The odds are waaaay against creating a duplicate UUID, but
it sure isn't a guarantee... You could ask Al Gore about odds, but I think
he's working on his resume...
Imagine this actual real scenario. You can look for yourself and see
that the createUUID() produces lousy randomness. Now, say you've got a nice
clustered CF server going, with, oh, 5 nodes. You fire the whole wad up at
the same time, so their tickcounts are within a few of each other. I'm sure
that if you ran a CFLOOP from 1 to 1000, on all 5 boxes simultaneously,
you'd either get at least one match, or a darn close.
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