Re: The term "theory" as in "database theory"

On Jan 26, 10:05 pm, "dawn" <dawnwolth..._at_gmail.com> wrote:
> [snip]
> > > 4. the branch of a science or art that deals with its principles or
> > > methods, as distinguished from its practice: music theory.
>
> > Now we have something, a description of a human pursuit. This makes as much
> > sense as #5 below.
>
> > > 5. a particular conception or view of something to be done or of the
> > > method of doing it; a system of rules or principles.

There you go. A combination of 4 & 5 seems like a definition that might apply best to cdt. Look, its absolutely fine to take an MV view and investigate it - others have discussed it on here without producing mass offence, because they approach the subject theoretically and scientifically because they will back up their analyses with rules and principles, follow them through logically and mathematically, be concise, address the disadvantages they generate, etc. T

hey have no need to fear an uproar, because they keep their arguments free of business politics and crusades! They might distinguish implementations with underlying model clearly. But and most importantly, they steer clear of hand way appeals to woefully unreliable /anecdotal evidence/ (which is like committing discursive suicide without a plethora of caveats attached to it).

After all if anecdotal evidence was of any merit we'd all believe in Ghosts, Telepathy, Martians, Elvis being alive, or that I can look at greasy sodden tea leaves to see if England are ever going to win a cricket match again.

>
> > Sounds the same as 4, generally speaking.OK, that was my impression too. So, one person might have 2VL in their
> theory and another might have 3VL, right? How would one judge whether
> one was better than another? I would think that would be by applying
> each system of rules along with some means of measuring which system
> produces better results in various areas. Judging database theories
> would be much like judging software products - what features does it
> provide, what quality requirements does it meet, etc. Does that make
> sense?

Not to me. Database theory is grounded in the nature of information in a dynamic world, and how it can be communicated and manipulated, and its integrity maintained. Logicians and Linguists have spent centuries addressing these issues, scientifically and diligently. We are far from getting to the truth of what information is, and how it best be handled, but we have progressed and it is through this sort of applied epistimology that advances will continue to be made. Progress does not occur through saying "my mate used this graph thing to organize his wii game collection and it was leet. I don't understand it doesn't 0wnage the world. It must be because all the man has have been lying to us all these years."

>
> > > 6. contemplation or speculation.
> > > 7. guess or conjecture.
> >"Ha! We'll get lots of wise-cracks on these two!Sometimes my statements align with 4 & 5, in which case they could be
> judged by what features are present and which are not. Sometimes I get
> responses or give statements that are more in the 6 or 7 category. But
> if someone guesses that that relational theory is better for xyz in the
> long term and I guess it is not, then a comparison of features (which
> we might do to judge database theory as mentioned above) is not
> sufficient because we can disagree on which approach is more
> feature-rich or meets the requirements best. We actually need to know
> which requirements we are aiming for and then perhaps collect emperical
> data, not just think "hey, it seems to me that relational theory should
> provide us with databases that are easier to maintain with quality data
> over the long term than other databases." But when I bring up
> emperical data, some indications are that this is outside the scope of
> database theory.

Having a 'theory' is not enough. One has to back it up, or develop it with a bit of scientific rigour for it to become worth people's time and consideration (and not embarrassing appeals to anecdotal evidence). Sadly empirical evidence is almost impossible to obtain in the field (as it is such areas as the Biological sciences, and especially in my old field Economics), so people have to appeal to other merits.

>
> So, I'm confused on how others are thinking one judges whether they
> have a good "database theory." There seem to be some who indicate that
> the judgment of whether a theory is good or not lies in the mathematics
> of the theory. I do not understand how this could possibly be the case
> (and that might be why I have been told that I do not appreciate
> theory). The mathematics of a theory could be absolutely beautiful and
> the resulting "database theory" could be awful, right? I do understand
> that some features on our list where we could do comparisons include
> "provability" and "query symmetry" but these are simply items on our
> requirements list, not the only items on the list nor the only measures
> of a theory. The feature list for databases (and DBMS's) is huge, and
> similarly for related database theory, I would think. One requirement
> I have for database theories, for example, is that they lead to
> implementations that are a "big bang for the buck" for companies using
> those products.

No, your "bang for buck" argument is spurious and always makes me cringe somewhat. It misses the fact that productivity wholly depends on the merits of a particular implementation, education levels of its users, what mindset they are used to, and a million an one other external factors. Imho, leave it well alone - it will just generate frustration to those who see it has little to no relevance to how good an underlying theory is.

I hope (perhaps foolishly) that you yet might heed some of these things and who knows, it may even generate real discourse! I still await a post without any agenda, or baiting, or getting drawn into business politics - perhaps a theoretical exploration of grouping and ungrouping aggregates? Regards, Jim.

>
> I also am not sure whether sometimes when a person writes "theory" they
> are referring only to the mathematics portion of the rules. For
> example, are "produce a nightly backup to disk" and "have a real-time
> operational database that is a duplicate of the OLTP database" possible
> statements in a "database theory" or not? Why or why not?
>
> Thanks for the discussion on this. --dawn
>
> > --
> > Kenneth Downs
> > Secure Data Software, Inc.
> > (Ken)nneth_at_(Sec)ure(Dat)a(.com)
Received on Sat Jan 27 2007 - 02:46:11 CET