Re: Re: Create unique non-autoincrement key for 700,000records?

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On Tue, 2008-12-16 at 09:21 +0100, Ondrej Kulaty wrote:
> I think he knows how to use it, he didn't show us a certain example where 
> and how he wants to use it, i just posted the way how i do generate an 
> unique identifier, if he use the first mentioned way - 
> AutoIncID+unix_timestamp - there can be a collision, when two users will 
> attempt to perform this task on the same id at the same time. yes, it's not 
> very probable but if you have system with many users it can happen

No it's impossible. Auto increment guarantees a unique auto incremented
ID. Adding the value returned by unix_timestamp() to this unique ID can
only create unique sums since both the auto increment ID and the time
are increasing. There cannot be a collision.

Cheers,
Rob.
-- 
http://www.interjinn.com
Application and Templating Framework for PHP


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