Re: [HACKERS] Patch for UUID datatype (beta)

On Mon, Sep 18, 2006 at 07:45:07PM -0400, mark@mark.mielke.cc wrote:
> I would not use a 100% random number generator for a UUID value as was
> suggested. I prefer inserting the MAC address and the time, to at
> least allow me to control if a collision is possible. This is not easy
> to do using a few lines of C code. I'd rather have a UUID type in core
> with no generation routine, than no UUID type in core because the code
> is too complicated to maintain, or not portable enough.

As others have mentioned, using MAC address doesn't remove the
possibility of a collision.

Maybe a good compromise that would allow a generator function to go into
the backend would be to combine the current time with a random number.
That will ensure that you won't get a dupe, so long as your clock never
runs backwards.
--
Jim Nasby                                    jimn@enterprisedb.com
EnterpriseDB      http://enterprisedb.com      512.569.9461 (cell)