"Tom Lane" <[EMAIL PROTECTED]> writes: > Mark Mielke <[EMAIL PROTECTED]> writes: >> Kless wrote: >>> [1] http://www.mysqlperformanceblog.com/2007/03/13/to-uuid-or-not-to-uuid/ > >> That's a general page about UUID vs serial integers. > > AFAICT the author of that page thinks that UUIDs are stored in ASCII > form (32 hex digits), which would indeed be inefficient.
Well he does say "In fact if you store UUID in binary form you can bring it down to 16 bytes so size is not really the problem." Though I'm unclear why he thinks a 4x increase in space usage is "not really a problem". If you have a highly relational database you can easily have half or more your columns in large tables consisting of foreign keys. If your database is i/o bandwidth limited that would be a huge effect. > I have no idea whether he knows what he's talking about with respect to > mysql, but it's certainly 100% irrelevant to the Postgres datatype. The rest of it seems to be pretty mysql-specific. Some of the problems are universal such as making index inserts especially random and making clustering impossible, but how much they hurt on different databases is going to be very different. -- Gregory Stark EnterpriseDB http://www.enterprisedb.com Ask me about EnterpriseDB's Slony Replication support! -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
