Re: Clean Object Class Design -- What is it?

On Thu, 19 Jul 2001 D_at_B.A wrote:

> In article <Ua057.81$YH1.29301777_at_radon.golden.net>, Bob Badour says...
> >
> >Why should vendors provide support for declarative integrity constraints
> >when they can fool customers into thinking that triggers and stored
> >procedures solve the problem?
>
> Do you really know all the performance, concurrency and other problems of
> implementing, say, subqueries in check constraints?
>
> >Why should relational DBMS vendors provide adequate support for domains when
> >the markets that demand them most scoff at the idea of using a relational
> >database?
>
> Is implementing user defined domains straightforward? Why then relational
> vendors come up with cludgy object/relational implementations instaed of just
> implemnting java type based domains? Why today java in RDBMS is just calling
> static methods?

If I have read what Bob has said before, his view is that current ORDBs do a bad job of supporting domains. I heard once that Ted Codd used to go around the world marking commercial systems as to how well they supported the Relational Model. No vendor did particularly well as I remember.

>
> >Why should vendors provide adequate physical independence when the markets
> >accept the status quo? Or even worse, when the markets assume that physical
> >independence harms performance?
>
> Do you really know how many conflicting goals query optimiser have? I know, you
> tell me that SQL is deficient, but what query language do you suggest?
>
> Note, that during long product history, users listen to the buzz, and vendor has
> to react, otherwise, it would loose competitive advantage. Yesterday, everybody
> thought CORBA interfaces are silver bullets, so vendor have to implement CORBA
> in the database. Today it's not hot anymore, so they scrap it. Tomorrow,
> everybody want's XML database, so vendor goes ahead and implements it as just
> another ugly addendum to relational database. Issues like why optimiser plan
> doesn't have monothonic selectivity on "where NAME like 'AAAA%'" are secondary,
> which only couple of users are aware of. And in order to get your query to
> perform you have to write it a certain way. So much for physical independence.
> In short, we have a product that users deserve.
>

Like you said, commercial issues often dictate.

akmal

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