Re: Re: 7.2 items

Tom Lane <tgl@sss.pgh.pa.us>

From: Tom Lane <tgl@sss.pgh.pa.us>
To: Franck Martin <franck@sopac.org>
Cc: Hannu Krosing <hannu@tm.ee>, "'Lincoln Yeoh'" <lyeoh@pop.jaring.my>, Bruce Momjian <pgman@candle.pha.pa.us>, PostgreSQL-development <pgsql-hackers@postgresql.org>
Date: 2001-05-14T14:39:34Z
Lists: pgsql-hackers
Franck Martin <franck@sopac.org> writes:
> The  uuidgen  program creates a new universally unique identifier (UUID)
> using the libuuid(3)
>        library.  The new UUID can reasonably be considered unique among all
> UUIDs  created  on  the
>        local system, and among UUIDs created on other systems in the past and
> in the future.

"Reasonably considered"?

In other words, this is a 64-bit random number generator.  Sorry, I
think the odds of collision would be uncomfortably high if we were to
use such a thing for OIDs ... certainly so on installations that are
worried about running out of 32-bit OIDs.  It sounds to me like uuidgen
is built on the assumption that only relatively small numbers of IDs
will be demanded from it.

			regards, tom lane