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Re: Constraints and Functional Dependencies

From: Marshall <marshall.spight_at_gmail.com>
Date: 24 Feb 2007 15:38:49 -0800
Message-ID: <1172360329.639706.265030@m58g2000cwm.googlegroups.com>


On Feb 24, 9:28 am, "Carl Federl" <cfed..._at_yahoo.com> wrote:
> <Anyone have any alternate formulas for functional dependencies or
> candidate keys? >
>
> My primary objection to using FOL to define constraints is that it
> would require our theory of data to have two different but similar
> languages, one for defining constraints in the FOL language and then a
> second language for manipulating relations.

It is an interesting objection.

For reasons I can't articulate, I find the RA easier for writing relational equations, and the RC easier for writing constraints. The difference is significant. (Anyone else care to weigh in on this?) If that holds at all widely, then it would be worth it to have both just for ease-of-use considerations.

Marshall Received on Sat Feb 24 2007 - 17:38:49 CST

Original text of this message

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