Re: Extending my question. Was: The relational model and relational

From: Bob Badour <>
Date: Mon, 24 Feb 2003 12:25:57 -0500
Message-ID: <rZs6a.296$>


It's hopeless. You are completely missing the point.


"Steve Kass" <> wrote in message news:b3dfa7$lnq$
> Lauri,
> Date's argument is this:
> What does AS mean by "/a/ penny"? Suppose I give him
> two pennies but assert I am giving him just one. How does
> he know I am wrong? The answer has to be: by counting!
> Thus, I submit that he /has to be able count pennies in order
> to be able to execute the first step of his algorithm/.
> Date is saying that multisets are invalid because they
> can't determine whether or not he is lying about what a
> penny is. If that is a requirement, then I fully agree that
> multisets don't meet that requirement. If at some point I
> need to design a database with such characteristics, I'll
> use a more suitable model.
> If Date gives AS two pennies, asserting that it is one,
> AS should first ask Date whether he has a question
> or is perhaps just trying to buy two cents worth of
> information (assuming Date equates penny with cent).
> If Date does ask how many pennies there are, AS
> should use Date's definition of a penny. If the database
> is currently in a state representing a multiset of 71 pennies,
> AS should report back to date that there are 35.5 pennies.
> No one is wrong. In many cases databases provide
> contextual answers. Many a database will report today's
> day of the week as Monday to an New Yorker, as lundi
> to a Parisian, and as ??? to a resident of Beijing. There's
> no reason the database can't report a numerical quantity
> in units, pairs, dozens or gross as well, on demand.
> SK
> Lauri Pietarinen wrote:
> >>All I need is to distinquish -- rather than count -- one can, then
> >>make the assumption that this separate entity has "the weight of one
> >>can" and that all cans in the bag have the same weight -- basically,
> >>the inductive hypothesis, but for unordered collections. Distinction
> >>is a more primitive operator than counting.
> >>
> >>
> >
> >I think Date has a valid point in that in order to weigh one
> >can you _have_ to be able to count it!
> >
> >see
> >
> >regards,
> >Lauri Pietarinen
> >
> >
Received on Mon Feb 24 2003 - 18:25:57 CET

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