[erlang-questions] Mnesia and autogenerated ids

zambal <>
Fri Aug 8 00:36:44 CEST 2008


On Aug 7, 11:19 pm, "Ulf Wiger" <> wrote:
> Now is guaranteed to be unique on a given node, while that node is
> running. Two different nodes can easily* generate the same now()
> value. That's why {node(), now()} is used.
>
> Of course, if the node is restarted and the system clock is altered,
> you can still have duplication of IDs*. This problem can be addressed
> by using NTP against a reliable time reference.

Thanks for the explanation. So if you would have one node that is
responsible generating new id's and all other nodes in your
application query this node, is there any other reason to not use
now()?

Best,
Vincent



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