Talk:Domain/key normal form

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[edit] Highest?

Is this a higher normal form truly? The example simply shows a combination of two attributes in one field, something that wouldn't even pass 1NF if you simply rewrote it as an array stored in a field, which it basically is. Gigs (talk) 05:31, 16 December 2007 (UTC)

I agree; based on the First normal form article, it's not 1NF, since evilness and eccentricity are two attributes being stuffed into one column. I wonder, what about a table with an “upper bound” column and a “lower bound” column, with the constraint that the upper bound is greater? That seems to have the same problem as the given example (two columns with an interdependent constraint), but would be much simpler (assuming I'm correct that such a two-column constraint violates DKNF). Also the solution is less obvious in this case. (My guess would be that you'd store the total range — upper bound minus lower bound — instead of the upper bound, and say the range must be positive; that'd pass DKNF now, right?) Luke Maurer (talk) 22:00, 21 May 2008 (UTC)