Re: Peter Chen and Charles Bachman

"Gene Wirchenko" <genew_at_mail.ocis.net> wrote in message news:htli9017k8k5e5iim1effkbu6f2lon9ldf_at_4ax.com...
> "Laconic2" <laconic2_at_comcast.net> wrote:
>
> >"Dawn M. Wolthuis" <dwolt_at_tincat-group.com> wrote in
>
> [snip]
>
> >Although some ER proponents argue for normalizing data in an ER model,
many
> >others do not. I tend to argue against normalizing data in the ER model.
> >In particular an entity, an order, can contain line item data that is
> >multivalued, or in 1NF parlance a "repeating group". If you implement
in
> >CODASYL you'll do one thing with it, if you implement in relational (or
> >"tabular") you'll normalize by decomposition, and if you implement in
PICK
> >you'll do yet a third thing with it.
>
> <EG> You may really have to implement the Fourth Lie: "Of course
> I'll respect you in the morning.", "I'm here from the government and
> I'm here to help you.", "The cheque is in the mail.", and "I
> denormalised for performance."
>
> I thought PICK was based on the CODASYL way. If not, what is the
> differentiation please?

I am unaware of any connection between the CODASYL designs and PICK, either historically or in looks, although both could likely be "modeled" with di-graphs. A CODASYL enthusiast would likely not consider PICK a DBMS. I have more experience with IMS than IDMS, but if I recall, IDMS also uses (used?) the concept of a schema (as a view) -- I could be wrong about that -- and typically includes DBA's in the mix, where the PICK approach does not. CODASYL was more strongly typed (lengths in particular) than PICK. PICK started out as an OS (then competed with UNIX and DOS and transitioned to residing on top of them). PICK runs within a virtual machine stemming from Wirth's P-machine (which is also the grandfather of the JVM). Writing software applications in COBOL and using IDMS as a DBMS really doesn't bear a lot of resemblence to software development in PICK (using DataBASIC, for example, along with Java or VB or whatever). It is conceivable, however, that the data modeling for each is similar.

> [snip]
>
> >I don't know what people who don't like ERD's do for analysis. When I
first
> >joined this forum, there was a lively debate between the OO enthusiasts
and
> >the regulars about the subject of subject matter expertise. The
prevailing
> >opinion among the OO enthusiasts seemed to be that there wasn't time for
the
> >implementors to learn the subject matter, so the best thing to do was to
> >design data structures that were subject matter independent.
>
> An old saying: "There's never time to do it right, but there's
> always time to do it over." OOP is great, but so is cheddar cheese.
> I use each as appropriate.

But only sharp cheddar -- life is too short to eat mild cheddar or milk chocolate, but that would (also) be a matter of taste ;-)

> >That's even farther from my way of thinking than your way of thinking is.
>
> Having just gotten back to this group, I have reading the last
> month or so in the last few days. Given the current iteration in the
> neverending battle between Good and Evil (relational/SQL vs. PICK (or
> the reverse if that suits your biases), I have an overdose of PICKism.
> Thank goodness that Dawn finds "post-relational" being as stupid a
> term for PICK as most of us do. (If the first thing that someone
> tells me about Their Way is a lie, it does something for their
> credibility, something very bad.)

Sorry for the overdoes of PICKishness, Gene (and glad I didn't ruin my credibility by using clearly-errant terms like "post-relational"). The comments about PICK are more about "NOT RELATIONAL" or "not only relational", but I have found that using PICK as the example is better than using an even more emotion-inducing example such as "XML" or worse yet "XML Database."

I might sound like an old lady stuck in some old technology, but I dont' think that's the whole of it -- I'm just trying to figure out why in the world we still teach relational theory (as it relates todata) as if it were TRUTH and don't teach other approaches that yield high productivity for companies (such as, you guessed it, PICK). Once my book learning and experience align better, I'll be at peace (well, only after the industry starts moving faster in directions I think more effective). smiles. --dawn

<snip> Received on Thu May 06 2004 - 00:20:21 CEST