On your "Quote of the Week -- 03/30/2003"

Massimo Dentico m.dentico@virgilio.it
Tue, 01 Apr 2003 05:05:27 +0200


[A preceding sending seems aborted, sorry for the evantual duplicate.]

Dear editors of DataBase Debunkings,

I just  noticed your  quote of  the week  from an  e-mail of mine to the
Tunes review mailing list.  I don't know if  you have read the  entire e
-mail or only an excerpt. Anyway the exact reference to an archived copy
of my e-mail is:

  http://lists.tunes.org/archives/review/2002-June/000174.html

You could link directly to this if you mind to take it in context.

I want to be  sure to understand the  fallacies you are pointing  out. A
first  inaccuracy could  be historical,  probably secondary  for you,  I
don't know, but in such case I'll be glad to be corrected.

Instead the most macroscopic fallacy is to call "data model" the "model"
(I lack a better word) of both  network and hierarchic  DBMSs,  which is
inconsistent with my quote of  Fabian Pascal's definition of data  model
in the same e-mail: data types, structure, integrity and manipulation.

I was inadvertently  using a terminology  taken from these  2 books (and
that to my knowledge is in widespread use) which I was referring at  the
beginning of my old e-mail.

One of the 2 is an italian translation of Jeffrey D. Ullman, "Principles
of Database  and Knowledge  - Base  Systems", Volume  I, 1988,  Computer
Science Press, Inc.

In chapetr 2, paragraph  2.1, Ullman defines a  data model as (my,  more
likely inaccurate, translation from Italian):

"[..] a mathematical formalism composed by two parts:

1. a notation to describe data;
2. a set of operations to manipulate such data.

[..]  Another is  the network  model that,  for data  description, uses
oriented graphs. [..]"

With  respect  to  Pascal's  definition,  this  lacks  *at  least*  data
integrity.

Is it correct this retrospective recognition of my errors?

Thanks for your attention.

Best regards.

P.S.: I am sorry  to have added confusion  to this subject (even  when I
was citing  you) and  for the  incorrect links  to your  site in  my old
email. Moreover, I hope that my bad English is comprehensible.

--
Massimo Dentico