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

From: Steve Kass <skass_at_drew.edu>
Date: Mon, 24 Feb 2003 19:46:14 -0500
Message-ID: <b3ee99$4aj$1_at_slb9.atl.mindspring.net>


I quite agree.

SK

Bob Badour wrote:

>Steve,
>
>It's hopeless. You are completely missing the point.
>
>Bob
>
>"Steve Kass" <skass_at_drew.edu> wrote in message
>news:b3dfa7$lnq$1_at_slb5.atl.mindspring.net...
>
>
>>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 http://www.pgro.uk7.net/x_duplicates.htm
>>>
>>>regards,
>>>Lauri Pietarinen
>>>
>>>
>>>
>>>
>
>
>
>
Received on Tue Feb 25 2003 - 01:46:14 CET

Original text of this message