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Re: Decline of Science: Computer Science and Databases

From: Alfredo Novoa <alfredo_at_ncs.es>
Date: 3 Dec 2002 07:19:14 -0800
Message-ID: <e4330f45.0212030719.68f2221d@posting.google.com>


"Carl Rosenberger" <carl_at_db4o.com> wrote in message news:<as5gf4$u0n$07$1_at_news.t-online.com>...

> The "cheap trick" is called object orientation.

It is not object orientation. It is only a very bad use for some OO techniques.

> It uses "network style datadesign" all over to handle and modify
> data, not just for generating reports.

Then it is even worse.

Don't you know that the network data model was discarded several decades ago?

> All I wanted to show is
> that it's a pain to set up a simple query for a high level class in an
> inheritance hierarchy

A query for a class?

Something like: select * from Integer?

>, if your class structure is scattered across
> multiple tables.)

Something like this?:

var Types real relation { Name Char }

    key { Name }
    foreign key { Name } references Identifiers;     

var SuperTypes real relation { Name Char, Parent Char }

    key { Name, Parent }
    foreign key { Name } references Types     foreign key { rename Parent as Name } references Types;

var PossReps real relation { Name Char, PossRepName Char }

    key { Name, PossRepName }
    foreign key { Name } references Types;

var PossRepComponents real relation

      { Name Char, PossRepName Char, ComponentName Char, TypeName Char }

    key { Name, PossRepName, ComponentName }     foreign key { Name, PossRepName } references PossReps;

> > Only unthinking hackers wants to store class hierarchies in a
> > database.
 

> Only unthinking theoreticians produce generalisations like this one.

Well, I meant the kind of class hierarchies you proposed.

I think storing a class hierarchy like:

                              shape
                                |
                              ellipse
                                |
                              circle

in a database could be a good idea.

> Your generalisation certainly is false for usecases where
> - a network model is used to hold data

Network models are totally obsolete.

> - only a hierarchical access path is necessary

Then you are talking about simple toys, not complex business applications.

> - time to market is essential

Then you should use a good SQL DBMS.

> - the class model may be constantly refactored and reducing

I don't think that class models like this:

                      shape
                        |
                      ellipse
                        |
                      circle

are very prone to be constantly refactored.

> maintenance work to do so is a must

A RDBMS would be very good for this.

> - navigation solves all issues perfectly and queries aren't needed

Again toy systems, but it is trivial to do it with a SQL DBMS and a RAD tool like Delphi, Oracle Forms or Visual Basic.

Regards,
  Alfredo Received on Tue Dec 03 2002 - 09:19:14 CST

Original text of this message

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