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

From: Marshall <>
Date: 2 Jun 2006 00:06:56 -0700
Message-ID: <>

Robert Martin wrote:
> On 2006-05-31 12:44:04 -0500, "Marshall" <> said:
> > Wow, I missed that one completely. "Isolate the data management
> > mechanism from the data model." How in tarnation is the data
> > manager doing to manage the data if it is isolated from the
> > data model?
> It's called decoupling. Generally it's based on dynamic polymorphism
> which is a lot of syllables that really mean function pointers. The
> idea is that you write the application program in such a way that it
> can manipulate the data in the data model without coupling it directly
> to the DBMS, or the details of the schema. The decoupling mechanism is
> very similar to the mechanism used to create device independence in
> operating systems like Unix.

That's a complete non-sequitur from the sentence I took issue with. You said, "Isolate the data management mechanism from the data model." This has a very clear denotation: it means the dbms should not know the schema of the data it is managing. This is clearly self-contradictory. Perhaps you didn't mean that? Perhaps the later "it's called decoupling" paragraph is more like what you really meant to say?

Marshall Received on Fri Jun 02 2006 - 09:06:56 CEST

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