Re: Has E/R had a negative impact on db?
From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Sun, 23 Apr 2006 13:11:17 GMT
Message-ID: <V1L2g.64571$VV4.1222924_at_ursa-nb00s0.nbnet.nb.ca>
>
> the enemy of good
>
>
> I honestly believe that this long discussion has lost sight of the idea that
> the E/R model is an analysis model, and not a design model. Arbitrary
> choices made during the analysis phase can be useful, in order to come up
> with a conceptual model that is easily communicated from one person to
> another. That's the main usefulness of an E/R model, IMO. If the E/R model
> were a design model, then arbitrary choices would be far more costly.
Date: Sun, 23 Apr 2006 13:11:17 GMT
Message-ID: <V1L2g.64571$VV4.1222924_at_ursa-nb00s0.nbnet.nb.ca>
David Cressey wrote:
> "JOG" <jog_at_cs.nott.ac.uk> wrote in message
> news:1145759385.737434.153510_at_t31g2000cwb.googlegroups.com...
>
>>Neo wrote: >> >>>>Just a thought. I don't like entities. In fact I despise entities, as
>
> the enemy of good
>
>>>information philosophy. >>> >>>What is your definition of an entity? What steps would one go through >>>to verify something is an entity? >> >>I refer to them as they are specified by Chen. I've already pointed out >>I believe their specification is impossible above simply being >>arbitrary so your second question makes no sense to me.
>
> I honestly believe that this long discussion has lost sight of the idea that
> the E/R model is an analysis model, and not a design model. Arbitrary
> choices made during the analysis phase can be useful, in order to come up
> with a conceptual model that is easily communicated from one person to
> another. That's the main usefulness of an E/R model, IMO. If the E/R model
> were a design model, then arbitrary choices would be far more costly.
Perhaps, our experiences differ. I have found the NIAM/ORM methods of constructing english sentences to describe the concepts more useful for communicating with domain experts.
Programmers like pretty pictures, but users' and business experts' eyes glaze over. This usually precedes: "That's good. When will the software be ready?" ;) Received on Sun Apr 23 2006 - 15:11:17 CEST