Re: Database design, Keys and some other things

>> A VIN, a bank account number, and an SSN are all surrogate keys. <<

No; read Codd's definiiton of a surrogate key. These are all industry-standard, externally verifiable keys with known validation rules. Honking BIG difference!! The big part of this is that they are EXTERNAL to the database.

When you use (longitude, latitude) for a location, is it also a surrogate? If so, wouldn't every key be a surrogate? I verify a location with a GPS; I verify a VIN, a bank account number, and an SSN by computers or phone calls. Just a different device .. Received on Wed Sep 28 2005 - 02:14:28 CEST