Re: Generating Unique ID
Re: Generating Unique ID
- Subject: Re: Generating Unique ID
- From: "Alastair J.Houghton" <email@hidden>
- Date: Fri, 5 Sep 2003 13:07:52 +0100
On Friday, September 5, 2003, at 11:14 am, Bill Cheeseman wrote:
UUIDs, which are governed by a formal specification available on the
Web,
are persistent, and they are guaranteed to be unique across all
machines
using the same algorithm to generate UUIDs, and for more than a
thousand
years into the future.
It's probably worth mentioning that UUIDs also have some limitations,
the most obvious being that there's a maximum rate at which you can
generate them in order to guarantee uniqueness. (I can't remember what
it is, but if you're generating hundreds of them a second, you need to
look it up.)
Historically there was also the issue that some machines didn't have
Ethernet cards (so no MAC address); there are quite a few UUIDs in the
Windows registry that appear to be a bit dodgy because of that problem.
(Windows uses the same UUID algorithm.)
Kind regards,
Alastair.
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