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

From: Dmitry A. Kazakov <mailbox_at_dmitry-kazakov.de>
Date: Thu, 1 Jun 2006 10:02:16 +0200
Message-ID: <12sh1oeeq72os$.1cm06guz61xq9.dlg_at_40tude.net>


On Thu, 01 Jun 2006 01:48:55 GMT, J M Davitt wrote:

> Using file systems to make your point is a very poor choice. Take a
> file, copy it over there. Identical content, different paths. Which
> is "real?" Which is a copy? Which one should I modify if I want
> my changes to persist? How do Suzie and Bob and Joey and Ron know
> which is the one I scribbled in? What's keeping track of that? A
> file system? No way!

Let you have copied an INTEGER from one table to another. Which one is real?  

(None, both are integers! (:-))

> These, and other, questions become de minimis in the relational model.

It is strange to hear talks about identity from RM side. I thought RM overcame that disease. There is no identity. Files are same, neither is real. Paths aren't same. Identity is a relation, isn't it? Now if you'd consider objects like (path,file), these could have identity defined as id((path,file))=path.

-- 
Regards,
Dmitry A. Kazakov
http://www.dmitry-kazakov.de
Received on Thu Jun 01 2006 - 10:02:16 CEST

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