Re: Lucid statement of the MV vs RM position?

From: Jon Heggland <jon.heggland_at_idi.ntnu.no>
Date: Mon, 08 May 2006 09:41:02 +0200
Message-ID: <e3msmd$v07$1@orkan.itea.ntnu.no>

Marshall Spight wrote:
> Jon Heggland wrote:

>> Then I don't know how to convince you. Shall I show you the grammar?
>> http://web.onetel.com/~hughdarwen/TheThirdManifesto/APPXI.pdf

>
> No, I think Bob got it right; I was talking in the abstract, and you
> were speaking specifically of TTM; we were using the same
> words but in a different way.

Well, then I am sorry for not saying explicitly several times that I was talking about GROUP as defined in Tutorial D in the Third Manifesto, leaving open the possibility that you can define "GROUP" to mean something else. But wait, I did!

But I probably should have guessed that your statement:

> (I don't know if D&D consider GROUP an aggregate or not, but
> it certainly meets the definition AFAICT.)

should be interpreted as "I don't know how D&D defines GROUP, but if you define it as an aggregate operator (iterated union), it certainly meets the definition of an aggregate operator."

>> Is that operator the aggregate operator SUM()? Certainly not; for one
>> thing, SUM() produces a numerical value, not a relation. Rather, it is
>> the relational operator SUMMARIZE, *using* the aggregate operator SUM as
>> part of its invocation. Do you agree with this?

>
> Sure.

I take it that you accept that Tutorial D's GROUP is not an aggregate operator, then.

-- 
Jon

Received on Mon May 08 2006 - 02:41:02 CDT