Re: foundations of relational theory? - some references for the truly starving

"Costin Cozianu" <c_cozianu_at_hotmail.com> wrote in message news:bn3nbs$seug1$1_at_ID-152540.news.uni-berlin.de...
> > It's late and I no idea whether these are known to anyone or everyone,
> > but I remember this, commissioned by Unidata, now an IBM db: maybe it's
> > of use?
> >
> > http://www-3.ibm.com/software/data/u2/pubs/whitepapers/nested_rdbms.pdf
>
> That's a marketing hogwash containing blatant inaccuracies and downright
> idiotic claims:
>
> "
> 2) Normalization of the tables requires the order number and the
> customer number attributes be stored twice for each order
>
> 3) Producing a report to show the data as in (Figure 1) requires thatb
> the three tables be joined. Joined are highly compute intensive
operations.
> "

Well, maybe I AM "ignorant AND stupid", but I went looking for definitions of 1st, 2nd and 3rd Normal Form and I didn't find anything to contradict the above statements. Maybe you can explain to me:

1. How to define relationships without some sort of tag field to point back to the main table. "Where tbl1.id = tbl2.tbl1ID" (2 above). Seems like SOMETHING has to be stored twice. What would be the relationship between an order header and an order detail, if not order number? Between the order header and the customer master? And wouldn't those relationships require some data to support them?
2. How to do joins without making multiple jumps into the database? The columns of data may be stored on different machines. But of course, theorists aren't concerned with the trivia of reality. Seems to me kike saying "All people can fly, theoretically. As long as you ignore the reality of gravity."

I'd always heard that a Science major says "Why does it work? (theory)", an Engineering major says, "How does it work? (practice)" and a Liberal Arts major says, "Would you like fries with that? (reality)" Maybe it applies to databases too.

Mark Brown Received on Tue Oct 21 2003 - 19:44:13 CEST