Re: Examples of SQL anomalies?

On Jul 1, 1:29 pm, -CELKO- <jcelko..._at_earthlink.net> wrote:
> >> What does that mean? <<
>
> The Greeks had a paradox:
> 1) A cat has one more tail than no cat.
> 2) No cat has 12 tails.
> 3) Therefore a cat has 13 tails.
>
> The word "no" is used two different ways. In the (1) "no" is a zero
> and in (2) it is non-existence.

This is totally irrelevant to the question at hand. You are raising a red herring.

> >> [But there are no members to add!] So what? <<
>
> ab nilo, ex nilo -- from nothing comes nothing.

You can quote irrelevant latin phrases at me all day long. "Semper fidelis tyrannosausus," as #21 yelled. This won't change the fact that the empty set has zero members.

Or see this:

http://en.wikipedia.org/wiki/Empty_sum

or this:

http://en.wikipedia.org/wiki/Empty_product

> >> That this is completely a non-problem is most evident with count. Start with a bag containing three bananas. Remove three bananas. How many bananas remain? How is that the least bit hard? <<
>
> But I have to have a bag first and it has to make sense to put bananas
> in that bag.

And you have to have a good breakfast before you start your day. How many bananas in an empty bag? Ask any four year old, and they'll tell you; as I said it's not a hard question.

I will anticipate your response and point out that bananas get overripe rapidly when left on the shelf for a few days.

> >> False! It's not from nothing, and it's not simply a convention. It's the identity of the operator being aggregated. <<
>
> Yes, zero is the additive identity. But this is a convention used to
> get rid of the empty set problem and preserve easy computations.

If you think that zero is the additive identity by convention, then you clearly do not understand what a convention is. There is no problem to get rid of.

After that, you said a bunch of irrelevant stuff which I'm just going to ignore.

Marshall Received on Wed Jul 02 2008 - 01:13:44 CEST