Re: Object-relational impedence

From: TroyK <>
Date: Mon, 3 Mar 2008 10:26:33 -0800 (PST)
Message-ID: <>

On Mar 3, 10:41 am, Bob Badour <> wrote:
> JOG wrote:
> > On Mar 3, 2:07 pm, Thomas Gagne <> wrote:
> >>All attempts by applications to access a DB's tables and columns
> >>directly violates design principles that guard against close-coupling.
> >>This is a basic design tenet for OO.  Violating it when jumping from OO
> >>to RDB is, I think, the source of problem that are collectively and
> >>popularly referred to as the object-relational impedance mismatch.
> > I wondered if we might be able to come up with some agreement on what
> > object-relational impedence mismatch actually means. I always thought
> > the mismatch was centred on the issue that a single object != single
> > tuple, but it appears there may be more to it than that.
> > I was hoping perhaps people might be able to offer perspectives on the
> > issues that they have encountered.  One thing I would like to avoid
> > (outside of almost flames of course), is the notion that database
> > technology is merely a persistence layer (do people still actually
> > think that?) - I wonder if the 'mismatch' stems from such a
> > perspective.
> It's pretty obvious to me: object-relational mismatch is to relations as
> assembler-object mismatch is to objects.- Hide quoted text -
> - Show quoted text -

Very well put. I'm filing this away in my brain for future reference. Received on Mon Mar 03 2008 - 19:26:33 CET

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