Re: 1GB Tables as Classes, or Tables as Types, and all that refuted

From: Alfredo Novoa <>
Date: Mon, 13 Dec 2004 17:01:16 GMT
Message-ID: <>

On Mon, 13 Dec 2004 08:16:47 -0600, "Dawn M. Wolthuis" <dwolt_at_tincat-group.comREMOVE> wrote:

>> You can have a class named Relation but you can not define a relation
>> type with an OO language.
>Again, why not?

Because OO languages lack that feature.

>You cannot really think that my argument here was that because OO languages
>permit me to name a type "Relation" that ...

So which is your argument?

>> You can read the pseudocode I posted.
>I've had trouble with my news reader and am getting caught up, so I'll take
>a look.

You replied to that post, but here is again:

var Customers real relation { Code Char, Name Char }

   key { Code };

var Orders real relation { Num Integer, Customer Customers }

    key { Num };

Here I am using a relvar as a type.

"Orders" is not a relvar, it is a bullshit.

>I'll read your psuedocode, but is there any product you can identify that
>has practical problems because of making this great blunder?

That is what D&D say in their book.

>> In the case described by D&D the confusion between types and relvars
>> is evident, but in many OO apps I have seen the mistake seems to be
>> that the programmers think that the SQL DBMS is only a weird
>> transactional file manager and the information must be managed by the
>> application using network (graph if you prefer :) structures, like in
>> the old days.
>You mean the old days when it took a week to write and deploy a new accounts
>payable system?

No I mean the old days when it took many man years to develop a rather simple system. Like with most of the current OO database projects.

>least 6 months now. Yes, I know -- there are problems with those systems
>that we were addressing with DBMS's, but I fear we threw the baby out with
>the bath water (an overly disturbing metaphor, sorry).

The DBMS approach was one of the biggest advances in the computer field, but most programmers are not aware of that.

Regards Received on Mon Dec 13 2004 - 18:01:16 CET

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