-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Mon, 26 Nov 2007 10:28:03 -0800 (PST) Richard Broersma Jr <rabroersma@xxxxxxxxx> wrote: > --- On Mon, 11/26/07, Joshua D. Drake <jd@xxxxxxxxxxxxxxxxx> wrote: > > > In "theory" the item that would be a natural key > > in this instance is the VIN. You would of course have > > to make some kind of allowance for cars that don't > > have a VIN (nothing in the last what... > > 50 years?). > > So this is why the service stations always record my cars VIN number > when I show up for oil changes. ;) Ofcourse, there is a whole > industry built around auto theft where they restamp the stolen car > with a differnt vin number. I wonder if these stolen cars end up > with duplicated VIN numbers or if the VIN's they are given do not > pass the the VIN check-sum (if such a think exists). They may end up with duplicate VINs but that isn't really relevant as at that point we know that one of the two (or six or whatever) cars are invalid, thus the "natural" key is still valid and designed to alert us if there is any potential problem :) Sincerely, Joshua D. Drake > > Regards, > Richard Broersma Jr. > > ---------------------------(end of > broadcast)--------------------------- TIP 1: if posting/reading > through Usenet, please send an appropriate subscribe-nomail command > to majordomo@xxxxxxxxxxxxxx so that your message can get through to > the mailing list cleanly > - -- === The PostgreSQL Company: Command Prompt, Inc. === Sales/Support: +1.503.667.4564 24x7/Emergency: +1.800.492.2240 PostgreSQL solutions since 1997 http://www.commandprompt.com/ UNIQUE NOT NULL Donate to the PostgreSQL Project: http://www.postgresql.org/about/donate PostgreSQL Replication: http://www.commandprompt.com/products/ -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) iD8DBQFHSxTtATb/zqfZUUQRAoDbAJ9h+NcHeyj7b1dmFAXl5uSWUbHzJwCfVOSW vBFs5lpCXrgeCwOu0wud9S8= =9AfY -----END PGP SIGNATURE----- ---------------------------(end of broadcast)---------------------------TIP 2: Don't 'kill -9' the postmaster