Re: Relation Schemata vs. Relation Variables
From: paul c <toledobythesea_at_oohay.ac>
Date: Fri, 25 Aug 2006 01:55:13 GMT
Message-ID: <5MsHg.464543$IK3.366035_at_pd7tw1no>
>
> I think there is a subtlety here that eludes you.
>
>
>
> Let's look at it a different way. Let's specify the candidate key
> as a functional dependency constraint.
>
Date: Fri, 25 Aug 2006 01:55:13 GMT
Message-ID: <5MsHg.464543$IK3.366035_at_pd7tw1no>
Marshall wrote:
> paul c wrote:
>> There must be a subtlety here that eludes me.
>
> I think there is a subtlety here that eludes you.
>
>
>> If a candidate key, k, of
>> a relation has a value of 1 in some tuple and a tuple in that relation
>> has a value of {k 1, x 2} then I would say that the value k = 1
>> certainly identifies that tuple.
>
> Let's look at it a different way. Let's specify the candidate key
> as a functional dependency constraint.
>
different? what else could it be, given the usual lingo/intent?
p Received on Fri Aug 25 2006 - 03:55:13 CEST