Re: OO and relation "impedance mismatch"

From: Laconic2 <laconic2_at_comcast.net>
Date: Fri, 15 Oct 2004 14:29:00 -0400
Message-ID: <5qadnW5UX_5ni-3cRVn-pA_at_comcast.com>


"Bernard Peek" <bap_at_shrdlu.com> wrote in message news:RV4eU7bFGAcBFwcf_at_shrdlu.com...
> In message <iz%7d.409134$8_6.338269_at_attbi_s04>, Marshall Spight
> <mspight_at_dnai.com> writes
>
>
> >Limiting classes to only be applicable to relational domains would be
> >hamstringing them.
>
> I've been thinking about this impedance mismatch for a while. One of the
> things that I think contributes is the assumption that classes are
> prescriptive rather than descriptive. That's a given if you approach the
> problem using the existing OO languages that I'm aware of. The impedance
> mismatch seems to be between OO languages and OO data storage systems.
>
> I'm visualising a system where a piece of code might be something like:
>
> CREATE CLASS REDTHINGS AS SELECT COLOUR = "RED"
>
> Thus classes would all be created dynamically as sets of objects meeting
> a selection criterion.

One of the things that I'm perplexed about is why the people who think about this impedance mismatch focus so much on the "class".

The few formal descriptions of object oriented modeling I've seen say that the "class" is an OPTIONAL construct in object oriented modeling, while the "object" is fundamental. Maybe I'm missing something. Can you clarify? Received on Fri Oct 15 2004 - 20:29:00 CEST

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