Re: no names allowed, we serve types only

Bob Badour wrote:
> Jan Hidders wrote:
> ...

...

>>>>> C.Date presents this argument very well in section 20.9 of an
>>>>> Introduction to Database Systems where he claims that a coloured
>>>>> circle is not a subtype of circle (or vice versa).
>>>
>>>> The tuple that represents the circle is not the same thing as the
>>>> circle itself. I find Date's argument rather unconvincing, to put it
>>>> very mildly. He is by no means an authority in this area, and those
>>>> that are mostly disagree with this position.
>>>
>>> Since when do you find argumentum ad verecundiam convincing? Hmmm?
>>> [peers over rim of eyeglasses]
>>
>> I don't, nor do I think it is without any meaning whatsoever.

Has Date ever said that a tuple is the same as a circle? That would surprise me.

Personally, I have a great deal of trust in what he writes. In large part my reason is that he is pretty thorough about examining the statements of other authors (not to say 'author' means authority, nor 'academic' for that matter), whereas he's pointed out that a number of them have declined to correspond with him. His body of writing is pretty large and I would say it deserves respect and public examination by all serious academics. I don't always agree or understand what he says but it is usually thought-provoking. Actually his dogmatic positions seem rather few, for example I don't think he advocates that every relational technique must be founded on mathematical principles that weren't necessarily originated for the purpose of information theory or a practical dbms.

Many of the people who have publicly argued with him struck me as hand-wavers.

Can't comment much on type theory (in fact I don't even understand how this thread crossed into that territory). This is a young field. It might be useful to remember that many medical 'authorities' of the 18th-century are not remembered that way today. Received on Wed Feb 24 2010 - 22:34:24 CET