Re: Multiple-Attribute Keys and 1NF

From: JOG <jog_at_cs.nott.ac.uk>
Date: Thu, 30 Aug 2007 20:13:36 -0000
Message-ID: <1188504816.047712.171390_at_z24g2000prh.googlegroups.com>


On Aug 30, 8:12 pm, Bob Badour <bbad..._at_pei.sympatico.ca> wrote:
> Yes. If you prefer, "logical addressibility".

Identity has a very specific meaning in set theory, hence the confusion. Addressibility makes a lot more sense to me.

> The term I have known for
> quite some time is "logical identity", but if you prefer, we can call it
> "logical addressibility".

The simple answer to your question is that allowing multiple attributes would break the guaranteed access rule. (Its probably worth pointing out that its seen a lot of contention anyhow).

To me the point of the rule is to preclude non-logical access via pointers and OID's, and in that I agree with it wholeheartedly. It was also aimed at proscribing set based values, and I agree with that too. Wouldn't change a thing there - and relaxing 1NF doesn't affect that as far as I can tell.

What negative impact do you envision? An insert it unaffected, as is delete, and an update still just replaces one proposition with another. The only real consequence I can see would be to where-clauses which would require a tweak. Received on Thu Aug 30 2007 - 22:13:36 CEST

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