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

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