Re: Views for demoralizing

"Alfredo Novoa" <alfredo_novoa_at_hotmail.com> wrote in message news:8p9s01pqrki6ko46a59ejhdapdij4emtvk_at_4ax.com...
> On Fri, 11 Feb 2005 06:49:43 GMT, Jonathan Leffler
> <jleffler_at_earthlink.net> wrote:
>
>>FP: Do me a favor and post a message in that exchange and say I am
>>asking her to post the link to our exchange from years ago and that I
>>am still waiting for her mathematical proof that MVDBs are relational,
>>which she promised then. :)
>
> I am afraid that her proof would consist in something like this:
>
> MVDBs use functions
> Functions are relations
> ---------------------------
> MVDBs are relational
>
> Ridiculous.

Below is a quote from my response to Date's questions about the MultiValue model. Pascal was mistaken, thinking I was going to say that this model was relational -- it definitely is not by most definitions from the database community.

'by your definition of "relational" as well as by Codds and others who have written on relational theory, the MultiValue model does not meet those definitions - it meets the mathematical definition instead.'

So, your guess was wrong on the one hand, but right on the other -- I did say that MultiValue databases could be modeled with mathematical functions, which are, of course (and surely you agree -- right?) mathematical relations. I'm not trying to pull the wool over anyone's eyes on this. I would like for our definitions to be precise and agreed upon to the extent feasible. If I have to write "mathematical relations" each time so that there is room for some other-than-mathematical-relation definition of "relation" in the database world, so be it -- let's be clear on our terms so we can communicate. Now that "1NF" seems to have been redefined, there seems to be some terminology to resolve in the industry and I'll vote for a return to the original definition of relation used by Codd in his 1970 paper, rathe rthan subsequent definitions that tossed in a variety of other constraints. This does not mean that there should be no term for what Date defines as "relation" in his most recent writings. Just, please, please use a new term -- it will make discussions so much easier. Think of all the time wasted simply trying to agree on a set of terms when we are talking-- it is really a shame, don't you think? --dawn   Received on Sun Feb 13 2005 - 16:58:20 CET