On Mon, 2006-11-27 at 14:36 -0700, Scott Ribe wrote: > > insert a new address, and update the users table to the new address_id > > Which changes the user's "primary key". My point was that having the address > id be part of the primary key is wrong. As I said, you don't *have* to do it that way. I was just giving an example. You could just as easily grab the address id, insert that into an archive table with a date stamp and then just update the address itself. Thus *not* changing the "Primary Key". Joshua D. Drake > Having it be a part of a key may be > fine for many uses. But it's contrary to the notion of primary key that > something that not only can, but will, change for many records should be > part of the primary key. "Unique" and "primary" are *not* synonyms. > -- === The PostgreSQL Company: Command Prompt, Inc. === Sales/Support: +1.503.667.4564 || 24x7/Emergency: +1.800.492.2240 Providing the most comprehensive PostgreSQL solutions since 1997 http://www.commandprompt.com/ Donate to the PostgreSQL Project: http://www.postgresql.org/about/donate