Re: The wisdom of the object mentors (Was: Searching OO Associations with RDBMS Persistence Models)

From: Mikito Harakiri <>
Date: 1 Jun 2006 09:45:29 -0700
Message-ID: <>

Cimode wrote:
> In a word, I am
> under the impression that SQL (which was not initially thought of as it
> is now) is becoming a limitation of the relational model.

This is urban myth. SQL is widely criticised for its NULL and duplicate treatment. There is several more little annoying inconsistencies. That's about it. On practice, I fire SQL query and rarely get a surprising result that can be attributed to SQL deficiency.

This is what makes SQL hard to replace by a superior language. Keep in mind that some widely sucessful SQL features like "group-by" are ad-hock and are not part of the relational model.

> Which is why
> a question may be asked which is: can OO bring something to that? I
> kept hearing about OO fuss about so many years that I am interested now
> as what it may concretely bring to relational implementation... For
> instance inheritance is something that may prove extremely useful in
> the implementation of subtype/supertype RTables.

I doubt naive OO method would contribute anything. If you want in-depth theory of inheritance, classification then check up formal concept analysis (Uta Priss has written a nice survey article). Formal concept analysis provides a nice set-theoretic model for many OO artifacts such as multiple inheritance, for instance. Received on Thu Jun 01 2006 - 18:45:29 CEST

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