Re: Newbie question about db normalization theory: redundant keys OK?

> There are two ways I would answer this. The first says that email
> address isn't a natural key -- it doesn't uniquely define a person any
> more than hair color does. The second is that the natural key hasn't
> changed, the entity -- a mailbox on a mail server -- has changed.

Absolutely - so we need to use something that won't change - an artificial key.

-- 
Tony Rogerson, SQL Server MVP
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