Re: Decline of Science: Computer Science and Databases

"Carl Rosenberger" <carl_at_db4o.com> wrote in message news:aqml8a$585$00$1_at_news.t-online.com...
> Alfredo Novoa wrote:
> > var Contract real relation {Contract Char, //30 other attributes
> > typical to all contracts} key {Contract}
> >
> > var ContractPositions real relation {Contract Char, Position Char}
> > key {Contract, Position}
> > foreign key {Contract} references Contract;
> >
> > var BuildingEngineeringContract real relation {Contract Char, // 30
> > building engineering specific attributes}
> > key {Contract}
> > foreign key {Contract} references Contract;
> >
> > Your post reflects a deep ignorance about database theory.
>
> Your posting reflects the incapability to understand a real-world
> problem and to develop a practical solution with existing tools.
>
> Following your approach, one would model all hierarchies into
> relations. Could you please outline, how a query to print out
> all contracts with all positions including all data special to
> all derived classes would look like?
>
> Here is mine:
>
> ObjectSet set = db.get(new Contract());
> while(set.hasNext()){
> System.out.println(set.next().toString());
> }

So, basically you are saying that your approach will print one and only one report, and a programmer must encode all of the logic for formatting that report and for handling report breaks etc. in one or more toString methods.

By omitting all of those toString methods, you dissemble with the clear intention of misleading the reader. You must only want suckers for customers.

> By the way:
> "The Third Manifesto" is very vague in it's recommendation
> for inheritance.
> "OO very strong suggestions":
> "Some sort of type inheritance should be supported."
> What does the term "type" represent in this context?

A type.

> - a domain?

That is a synonym, yes.

> - a tuple?

Tuples are values, which of course have a type.

> - a relation?

Relations are values, which of course have a type.

> - a scalar?

Define scalar. While I don't have the book in front of me, I recall they were very clear that this concept is not particularly well defined.

> - a relvar?

A variable is a variable and not a type. I found the book very clear on this point.

> "Type" has been used for all of the above earlier in the paper.

Really? Where?

> Extremely interesting also:
> "OO Proscriptions":
> "Relvars are not domains"

Of course not. Variables are not types.

> Sure they can't be. Relations match to object members in OO.

Actually, relations match to a logical universe of objects.

> ...or does the above sentence in the third manifesto prohibit
> this use?

I agree. It does proscribe such use.

> Anyhow I think your suggestion violates the principles
> proposed by Darwen/Date, Alfredo. "Domains" (or "the term
> object class as it is sometimes used") are scalar types and
> they miracoulously disappear somewhere in your data machine
> and have nothing to do with relations.

I see what Alfredo meant about your posts reflecting a deep ignorance.

> ...gee, I think I need to write an article about this funny
> manifesto one day.

Well, they did publish the book and the article in SIGMOD to promote discussion. If you think you have something to contribute, I encourage you to do so.

> I pass the word back to the original author and his
> "one upright small Utah company in danger of saving the
> world from the decline of computer sciences and databases".

I guess the original author has not yet learned that "there is no stopping the invincibly ignorant." -DT

> Kind regards,
> Carl
Received on Mon Nov 11 2002 - 05:50:01 CET