Re: MV Keys (was: Key attributes with list values)

mAsterdam wrote:
> dawn wrote:
> > ... What does it mean that a list is a key? If
> > I change one value in the list, does that make it a new key? I would
> > think so.
>
> If I change the order of the items in the list,
> does that make it a new key? I would think so. (See below)

Yes, I too often mix sets & lists when I think in terms of the MV data model, which has only list attributes in which conceptual sets & lists are both implemented.

>
> > It might model a proposition something like
> >
> > The team with people whose ID's are 112233 and 123456 has a best run of
> > 38 seconds in the potato sack race.
>
> The team with people whose ID's are 123456 and 112233 has a best run of
> 38 seconds in the potato sack race.
>
> Would be the same proposition, right?
>
> So, in this example we have a set-key, not a list-key.

Yes, unless we add to the proposition so that it matters who's on top -- perhaps that person is the lead person, the one we want to contact, the one whose left leg is in the sack, the parent...

Cheers! --dawn Received on Sun Feb 26 2006 - 15:21:52 CET