Re: Who first (publicly) asserted 3NF is "good enough"?
From: Jan Hidders <hidders_at_gmail.com>
Date: 19 Sep 2006 01:56:03 -0700
Message-ID: <1158656163.402734.26160_at_e3g2000cwe.googlegroups.com>
> And, as Bob pointed out, for a lot of commercial apps, there is an
> industry standard or internally defined key that you have to use (UPC,
> EAN, VIN, ISBN, etc.), so most of the tables have a simple key. Also,
> if a table is all key, then it is in 5NF.
Date: 19 Sep 2006 01:56:03 -0700
Message-ID: <1158656163.402734.26160_at_e3g2000cwe.googlegroups.com>
-CELKO- wrote:
>
> And, as Bob pointed out, for a lot of commercial apps, there is an
> industry standard or internally defined key that you have to use (UPC,
> EAN, VIN, ISBN, etc.), so most of the tables have a simple key. Also,
> if a table is all key, then it is in 5NF.
What exactly do you mean by "a table is all key"? Is it "every column is by itself a candidate key" or "all columns together are a candidate key"? In the first case you are right, but in the second case your statement would not be correct.
- Jan Hidders