Re: A different definition of MINUS, part 4

From: Bob Badour <>
Date: Fri, 09 Jan 2009 23:20:41 -0400
Message-ID: <49681419$0$5499$>

paul c wrote:

> Bob Badour wrote:
> ...

>> The notation may also have some name scoping issues, but I think we 
>> are both on the same page about the relation equality comparison 
>> providing both quantifiers to the algebra.

> I suspect so too. It's been many years since I used any SQL products
> much, maybe some of them have a relation comparison operation now, but I
> don't remember any. My hunch is that any implementation language that
> doesn't have such an op is not likely to be defined on much formal logic.

I strongly doubt any SQL dbms supports table comparison. I have no doubt the vendors would say "That would be too slow and expensive" instead of doing their jobs. Received on Fri Jan 09 2009 - 21:20:41 CST

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