Re: Why all the max length constraints?

Note: there is no answer to the OP question nor even advancing of it below, just banter out of frustration, for what it's worth.

David Cressey wrote:
> "mAsterdam" <mAsterdam_at_vrijdag.org> wrote in message
> news:4479af0b$0$31647$e4fe514c_at_news.xs4all.nl...
> > dawn wrote:
> > > Keith H Duggar wrote:
> > >
> > >>dawn wrote:
> > >>
> > >>>... Why give a max length to
> > >>>an attribute that doesn't conceptually require such? Why
> > >>>can't the DBMS handle that for you (efficiently, of
> > >>>course)?
> > >>
> > >>Who says they cannot? Do you realize that even if no DBMS
> > >>implementation has yet done so, this is not evidence of
> > >>impossibility.
> >
> > > That would be the reason for my question. I am asking what is the
> > > reason that all of the implementations of the RM work with a max length
> > > constraint on attributes. So I should have written "why couldn't the
> > > DBMS...", perhaps, but most would understand the rhetorical technique,
> > > I would think.
> >
> > Even better:
> > "Why don't the DB designers let the DBMS handle it."
> > (Summary of my answer your OP: Because they trust
> > specifying it from earlier solutions.)
> >
> > As soon as you say "can't" in relation to a pet tool or model
> > you are waving a red cloth in front of a bull.

Yes, and I should have said "couldn't" instead of "can't". I will try to be more cautious.

> > Not unlike Neo's unfounded "prolog can't do this" or
> > "RM can't do that" statements repeated ad nauseam.
> >
> > This gives room to responses like:
> >
> > >>This is a classic example of argument from
> > >>ignorance or the burden of proof logical fallacy.
> > >
> > >
> > > You seem to think I'm arguing something when I think I am asking
> > > something.
> >
> > You shouldn't have waved the red towel :-)

If it had been a verbal face-to-face discussion, my choice of terms would not have been a problem. I write with a speaking style but will try to be more aware of where someone might jump to such an incorrect conclusion if they are thinking the worst of me.

> > >>And yet
> > >>you imply this fallacious claim from the start of the
> > >>thread. Do you understand this is a logical fallacy?
> >
> > [snip etc. etc.]
> >
> > > I have no answer I'm driving at, but am trying to understand. I have
> > > worked from the user to the app-implementation of many varied "data
> > > processing" systems, but have never written a DBMS tool. I do not have
> > > enough understanding of what is under the covers of any dbms to know
> > > what the reason would be for the max length constraints on attributes.
> >
> > Here you are suggesting again they aren't part of
> > the database design but part of the dbms.
> > They are not - another red towel. You could easily make
> > your statement in a way which shows you understand
> > that difference.
> >
> > [snip]
> >
> > > I could read numerous papers and learn enough so that I could produce
> > > an implementation of the RM myself, at which point I would know why I
> > > wanted those attribute length constraints.
> >
> > The db designer determines attribute length constraints, not the dbms.
> > Why do you ignore this difference?
> >
> > [snip]

>

Yes, I try to put smilies or other clues in so people know if I'm aware of joking or pushing buttons on purpose. One friend told me years ago that I had a U of M(ichigan) sense of humor (and I was around U of M until the age of 6 so maybe that's true).

However, I do not knowingly state things that I don't agree with. I'm not playing devil's advocate. I have a perspective which I know comes more from the "programmer" than "dba" perspective. While I doubt I state many opinions where I'm the only IT professional holding such an opinion, I might sometimes be the only one stating it on cdt. I know I'm not all-knowing nor 100% accurate, and I learn a lot and have refined my own thinking considerably from hearing the perspective of you and others. I have not changed every opinion I have, however, perhaps because they are not all wrong ;-)

> However, she claims to be a well seasoned programmer on all kinds of
> systems ranging from IMS to Oracle,

Seasoned (I prefer that term to "mature"), yes, but I try not to make claims, just provide anecdotes where I think relevant. I have seen successes and failures and have had enough experiences to form some opinions, again, some of which might be incorrect and skewed by my experiences, so I like knowing what others think too. This would be the case for anyone, I would think.

> a technical leader, a manager, and a
> college professor.

You missed "mom" and a few other important roles I'll skip. While I will claim to have done plenty of coding with IMS (quite some years ago), I have done only a little programming with Oracle, MySQL, and PostgreSQL, and none of that very recently, having more experience in mgmt with SQL-DBMS's as well as Pick. I don't have a Ph.D. and have only taught during 5 years of my career to date, while spending more than 25 as a practitioner in one role or another. These are simply facts. It bothers me when you or anyone says I'm claiming something since it is very unlike me to try to flex any muscle or even want to do such. The primary thing I've claimed is ignorance, which means that my detractors and I agree on at least that.

> Yet she claims to be ignorant of things that any of the
> rest of us would expect EVERY such person to know.

If people want to tell me how ignorant I am, I don't mind agreeing. I have anecdotal, but not scientific, evidence that men are less inclined to admit ignorance or even to show it with their questions. If you would prefer that I tell you that I know a lot more than some people around here give me credit for, then I can do that, but I've never met a person who was not ignorant and I'm no exception.

Do you have an example of something that I have said I do not know that EVERY person who has been in the software development profession for a quarter of a century does know or should know? I don't doubt I've missed something, but I suspect everyone has.

> We're never going to be able to check out her knowledge base.

Since I'm writing here to learn and not teach, I guess that would be difficult since I ask questions for which I don't know the answer. However, I suspect there are a few clues, whether here or in my blog, that might lead you to believe that I'm not completely ignorant in the area of s/w development, right?

[BTW. I'm headed to the Seattle area (where I have never been before) and speaking at a little gathering there on the 15th. If anyone is out that way and wants to chat with me in person (some exceptions may apply) or hear me speak (2 talks, one on AJAX and the other on data modeling, to a Pick audience), let me know (I think they charge a small fee for the meeting to cover expenses).]

> Not even if
> she were imprisoned in Guantanamo Bay with Bob Badour as a guard.

Laughing.

> So we're just going to have to take if for granted that she is who she says
> she is, and doesn't know what she claims not to know.

More laughter. I was unaware of claiming anything outside of telling stories, and I don't mean to be claiming I'm anything or anyone, brother David, just a human being with questions and opinions.

> The beauty of having these conversations is that you can have the same
> conversaion a couple of years later, try another tack, and see where that
> leads. It reminds me of "Groundhog Day".

Me too. Maybe I'm forgetting things, but I think I'm asking different questions or at least seeking the answer to a different question each time. Someone once pointed out in cdt that I was repeating a question a year later. I can only claim middle age, hormones, or whatever reason for such a brain failure. My memory is sometimes fuzzy, perhaps the first stages of alzheimers (no, I shouldn't joke about that, my mother-in-law died of it). Do you know women over 45 who do not have such memory lapses? Tips are welcome, but I do my best.

If this particular question (max length constraints) has been asked and answered before, my apologies, but then it should be really easy to provide a logically convincing answer the second time around. I don't completely know the answer now (in spite of all of the responses), so maybe I'm not just ignorant but brain dead. Thanks for putting up with me in spite of that, David. Cheers! --dawn Received on Sun May 28 2006 - 23:52:57 CEST