Re: Relation or attribute and why

Bob Badour wrote:
> David Cressey wrote:
>
> > "dawn" <dawnwolthuis_at_gmail.com> wrote in message
> > news:1148432908.908347.174660_at_j55g2000cwa.googlegroups.com...
> >
> >>Gene Wirchenko wrote:
> >>
> >>>On 23 May 2006 15:44:15 -0700, "dawn" <dawnwolthuis_at_gmail.com> wrote:
> >>>
> >>>
> >>>>Gene Wirchenko wrote:
> >>>>
> >>>>>On 23 May 2006 13:44:29 -0700, "dawn" <dawnwolthuis_at_gmail.com> wrote:
> >>>>>
> >>>>>[snip]
> >>>>>
> >>>>>
> >>>>>>In my example, the conceptual data model includes: name, firstName,
> >>>>>>lastName with relationships such that name has-a firstName and name
> >>>>>>has-a lastName.
> >>>>>
> >>>>> That is part of the logical model. The conceptual model is the
> >>>>>business statement.
> >>>>
> >>>>The identification of name, lastName, firstName and the relationships
> >>>>among these terms is not part of the business scope and definition, the
> >>>>conceptual data model? What would the CDM include related to these
> >>>>terms? I put everything that is conceptual and not directed to a
> >>>>particular implementation model (such as the RM) in the CDM. Where do
> >>>>you draw the (possibly fuzzy) line? --dawn
> >>>
> >>> Possibly fuzzy, but nonetheless.
> >>>
> >>> Conceptual might fit on a napkin: "We want an E-commerce Web site
> >>>for selling our products. It has to be able to handle North America,
> >>>but we plan to go international, so have the capability to add other
> >>>languages, etc. easily without rewriting large chunks. We want
> >>>someone able to complete an order quickly. Do not forget good
> >>>security. OtherCorp recently had a bad situation, and they are taking
> >>>a kicking. Now is our chance, if we do it right."
> >>
> >>Those are high level requirements, but not a conceptual data model.
> >>Conceptual, yes; CDM, no. You need at least an ORM, ERD, or a cleaner
> >>list of propositions related to these requirements, I would think.
>
> David,
>
> If you are going to interract with the self-aggrandizing ignorants,
> please, take the time to point out the most fundamental and profound
> points of their ignorance. Failing to do so only serves to reinforce and
> to spread the widespread ignorance and misconception in our industry.

What an adolescent approach to a dialog, Bob. Cut it out. Every time anyone replies to me are you going to insult me in your response to that person? What do you gain by doing this? For what are you trying to compensate? I don't know how to help you with whatever issues you might have, but would appreciate it if you would stop harrassing me in this way.

> A conceptual model deals with information and not solely data per se. As
> such, the term conceptual data model is ignorant nonsense.

I use an approach used by many in the industry (including Date, IIRC) of equating "data" and "information" for the purposes of conceptual and logical modeling. So, I agree that we are talking about an information model both when discussing a CDM and an LDM.

> The self-aggrandizing ignorant further confuses pretty pictures with
> what they represent. ORM and ERM are diagraming tools one uses to draw
> pretty pictures of conceptual models. (ERD is a diagramming tool to draw
> pretty pictures of logical designs.) The diagrams are not the models any
> more than a tabular picture of a relation alters its degree.

A tabular picture of a relation might be a model for that relation, right? Models can take many forms. Both a blueprint and a miniature building could be models for a particular building. Similarly, an ORM diagram, an entity-relationship diagram, and a set of propositions can all be models for capturing the data (information) requirements for a system. Each of these might be considered a model for the data model, a way of representing it.

> >>> Logical gets into the details, but not the implementation.
> >>
> >>A typical use of the term would allow for a conceptual data model to go
> >>from high level to detailed (in the end). [Although if a decision is
> >>made earlier that the requirements have been captured sufficiently to
> >>do flesh it out using common sense in a transition to an LDM, I can
> >>live with some agility.]
>
> See what I mean? Here the self-aggrandizing ignorant once again pretends
> that ignorant nonsense like 'conceptual data model' has meaning.

As with any other terms, it has meaning if it is defined. I have described such terms before, including in my blog at http://www.tincat-group.com/mewsings/2006/01/naked-model.html and others have also defined and described them similarly. If your definition differs from mine or your term for the same definition differs from mine, there is no reason to continue with the name calling -- simply explain your terms and definitions if you are not flexible enough to expand your glossary or adjust to the language used by someone else.

> Then
> she demonstrates profound ignorance and confusion between a logical
> design and a logical data model, among which one finds the relational
> data model, the network data model and the hierarchic data model,
> themselves.

A logical design of a system includes a logical data model by my use of the terms, whereas a data model might be the RM, a network model or a hierarchic data model. I think my use of these terms aligns with many in the industry.

> The surest sign that Dawn is a crank is her ignorant parroting of
> fashion statements like 'agility'.

Yes, a sure sign that I haven't a clue about anything would be the use of terms commonly used in discussions regarding software development ;-(

> You do no service by repeating such ignorant nonsense without challenge
> on the most fundamental level.

Interesting tactic to take your abuse of me to each person who talks with me. This intimidation technique might fall into the "make it so unpopular or risky for anyone to talk to her that none will have the courage to do so and she will be driven out of the community" pattern (yes, it needs a shorter name, perhaps simply "bully"). Thanks to David and others who are not intimidated by Bob's approach. Yes, he causes me a certain amount of pain, but I try not to let his continued intimidation strategies get to me (although I'll admit they do).

> >>I once considered the LDM to be implementation-independent, but after
> >>reading other definitions the logical data model appears to be data
> >>model dependent to most who use the term. In that case, you would not
> >>have the same logical data model for an RM implementation as an MV
> >>implementation, for example.
>
> Here, again, the self-aggrandizing ignorant shows her profound ignorance
> regarding logical data models. The relational data model is, itself, a
> logical data model.

I think even Pascal would disagree with your use of the terminology this way. The RM is a data model, a specific logical data model would relate to a specific problem domain. If your terminology is different, feel free to write it up and explain it as I have with the terms I am using. Perhaps we can add some of these to the cdt glossary.

> A logical data model is a formalism for the symbolic
> manipulation of data. A specific set of base relations and views is not
> a logical data model nor is a specific set of records and pointers.
>
> Of course! A logical design depends on the logical data model one
> targets! How could it not? The whole point of a logical design is to
> describe the represention of some subset of the information

A logical design in my terminology would include all of the design to implement all use cases identified in the analysis of a system. It might include workflow design as well as data/information design as found in a logical data model. I can understand that those who might not work with any aspect of software other than DBMS's might remove the term "data" from the LDM, but that doesn't work well in the broader context.

> in a form
> suitable for symbolic manipulation, which necessitates one represent the
> data according to the structures and operations of the formal system. Duh!
>
>
> > Agreed.
> >
> > The LDM is data model dependent.
>
> See the trap? By failing to recognize that Dawn is nothing more than a
> self-aggrandizing ignorant spouting volumes of ignorant nonsense, you
> fall into the trap of repeating the ignorant nonsense yourself.

David seems to be well able to think for himself. If his terms and mine align, perhaps yours are the ones in need of being clarified.

> What point were you really trying to communicate when you wrote the
> tautology above? The relational model depends on the relational model?
> The network model depends on the network model? I think such simple
> tautoloties go without saying because saying them conveys no information
> whatsoever.
>
> Presumably, you meant to say something different.

I doubt it.

> It's also a design model, not an analysis
> > model. Elements of the LDM pertain to the solution domain, not the problem
> > domain.
>
> Once again, you repeat her ignorant nonsense. A logical data model is a
> formalism for symbolic manipulation, and formalisms are domain independent.

An LDM by my definition as well as that of others is related to a specific domain. A data model is domain independent.

> People who insist that there is only one viable data model tend to
> > nerge the LDM with either the PDM or the CDM. Most of the RM "catholics" in
> > c.d.t. merge the LDM with the CDM, because they think that selecting a data
> > model is a choice with only one answer.
>
> Now, that is just insulting horseshit. Are you projecting your own
> limitations onto others? Or are you just assuming that, because people
> contributing to a theory newsgroup primarily discuss the formalism and
> the theory, they are ignorant of all else?
>
> I find the statement both backhanded and ignorant. It insults all of the
> legitimate contributors here. Shame on you!

Give it a rest, Bob. You are doing yourself no favors with this approach. Sure, you have some disciples, just like any bully has, but this isn't really who you want to be, is it? For whatever is going wrong in your life that drives you to being a bully even as an adult, I hope you are able to attend to it and I wish you well in spite of yourself.

--dawn Received on Wed May 24 2006 - 21:49:58 CEST