JOG wrote:
> Bob Badour wrote:
>
>>erk wrote:
>>
>>
>>>JOG wrote:
>>>
>>>
>>>>are you telling me that two Cans of Campbell's have no identity without
>>>>an artificial label? If that were true you would not be able to
>>>>distinguish them, yet you can. What, then, is that distinguishing
>>>>property?
>>>
>>>
>>>That's a deep philosophical issue for William Kent to answer, and one
>>>which depends critically on formal definitions of "identity", "same",
>>>"equivalent", "equality", "distinguish," etc. Whether you assign a
>>>number (which may or may not be printed on the can), or an RFID, a
>>>database has no way to distinguish them unless you give it that
>>>artifical label. I agree the cans are distinct in the real world, and
>>>have identity. It makes no real difference for most of the data we care
>>>about. If I spill the pyramid of cans, and hand you an undented one,
>>>will you be able to determine whether it's the one you were eyeballing
>>>before I knocked them down? So when physical location changes, and you
>>>don't track it explicitly, identity is lost - still there, but unknown
>>>to us.
>>>
>>>A database is not the real world. Since a database concerns known
>>>facts, the limits of our knowledge (e.g. whether you can know which of
>>>the nearly-identical cans you want) are direcly reflected in our
>>>ability to design and maintain a database.
>>
>>Not only the limits of our knowledge but the limits of our interest. Do
>>we really care about the identity of individual cans of soup?
>
> It's good soup Campbell's bob.
But it's all good soup if it's Campbell's.
Now, on the other hand, if it were wine or a single-cask single-malt
scotch or a limited edition Andy Warhol print...
Received on Thu Aug 17 2006 - 12:04:41 CDT
