Re: Does Codd's view of a relational database differ from that ofDate&Darwin?[M.Gittens]

Alfredo Novoa schrieb:
> On Tue, 21 Jun 2005 19:02:20 GMT, Jan Hidders
> <jan.hidders_at_REMOVETHIS.pandora.be> wrote:
>
>

>>>>If you restrict yourself to the structural side of the data model, i.e., 
>>>>how data is structured, then they are the same. (With the additional 
>>>>remark that we are looking at the pure OODB data model
>>>
>>>Such a thing does not exist.
>>
>>Jan Van den Bussche , Jan Paredaens, The expressive power structured 
>>values in pure OODB's (extended abstract), Proceedings of the tenth ACM 
>>SIGACT-SIGMOD-SIGART symposium on Principles of database systems, 
>>p.291-299, May 29-31, 1991, Denver, Colorado, United States

There exists everything that has a reference. And vice versa: no reference - no object (even if it "really" exists). Once OODB has a reference then we assume that such a thing exists (even if it does not "really" exists).

> Why “The Object Model' is Not a Data Model, RELATIONAL DATABASE
> WRITINGS 1994-1997
>
> and:
>
> http://www.dbdebunk.com/page/page/622923.htm

That's a biased opinion of those who prefer some other approach about what they do not like. If somebody does not like, say, "Theory X" then it does not mean that this theory does not exist.

The whole discussion is probably about the term "model" which is going to be privatized and exploited by only one group with the permission to be used only in one context. For example, if I propose to use 3 boxes with paper documents identifed by real numbers for storing my data then is it a data model? I can store my data, I can retrieve and manipulate it. I can update it. Is it a data model? I mean that independent of OODB usefulness and our opinion it can be qualified as existing. (But maybe it is obvious and nobody doubts.)

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