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From "Brendan Poole" <>
Subject RE: unique key generation
Date Wed, 09 Feb 2011 08:21:30 GMT

Are you sure about those odds? Winning the UK national lottery has a chance of 13 983 816
to 1 so for just 2 days the odds are
13 983 816^2 = 1.9554711 x 10^14

     Brendan Poole
     Systems Developer
     NewLaw Solicitors
     Helmont House 
     Churchill Way
     029 2078 4283


From: Kallin Nagelberg [] 
Sent: 08 February 2011 03:38
Subject: Re: unique key generation

Pretty sure it also uses mac address, so chances are very slim. I'll check out time uuid too,

	On 7 Feb 2011 17:11, "Victor Kabdebon" <> wrote:
	Hello Kallin.
	If you use timeUUID the chance to generate two time the same uuid is the following :
	considering that both client generate the uuid at the same millisecond, the chance of generating
the same uuid is :

	1/1.84467441 × 1019

	Which is equal to the probability for winning a national lottery for 1e11 days in a row (
for 270 million years).
	Well if you do have a collision you should play the lottery :).
	Best regards,
	Victor Kabdebon
	2011/2/7 Kallin Nagelberg <> 

	> Hey,
	> I am developing a session management system using Cassandra and need
	> to generate uni...

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