Re: foundations of relational theory?

byrmol wrote:
[originally]

 > 1) It has a general theory that has gone unchallenged for hundreds of
 >  years. (Set theory - Georg Cantor 1874, Predicate Logic from
 > Aristotle 322BC to Frege, Peno, Godel and Turing & Church (1936) who
 > prove that it is not "decidable").

 >I assume (and I can stand corrected) that this is set theory,
 > and while  relational theory springs from it, it's a stretch to imply 
 >that relational db theory was somehow even postulated in 1874 or 
 >before. But as I say, the theory may be provena[n]ced there.

Please read original quote. you reference "set theory?" there clearly. And the implication is that relational db theory links to that, and has been unchallenged etc.

somebody wrote:

 >> This model has the advantages of Forced Data Integrity, the
 >> end user does not have to know our data model. Essentially it creates
 >> customized mini-sql engines for our data objects. As I study this
 >> model more and play with it with Microsoft .net, Disconnected
 >> datasets, and XML data sets, I really feel this is the future.

> This quote gave me a good chuckle, because I am currently on a project
> that does this. Nearly the entire enterprise's schemas are replicated
> outside the DBMS's into these XML schema (XSD) for validation before it
> hits the data tier.
>
> Guess what happens... Any DB change HAS to be reflected in the middle
> tier. The middle tier has become a memory hungry, CPU churning pig with
> the added bonus of wiping out all logical/physical separation advantages
> that the DBMS had and for good measure coupling the data tier with the
> middle tier....
>
> "Welcome to the dumb future"

no, "welcome to the real world," is more like it. 3-tier models (even if I also disagree with the philosophy,) will continue to gain acceptance, and the double validations will be a fact of life. The piggishness of the middle tier is just an example of bad implementation and has no relevance.

Come to think of it, if you believe that the middle and upper tier programmers can do a good job, you could remove all data integrity constraints from the db, and let it do what it does best-data storage, retrieval and (physical) data integrity (duck.)

Chandru Murthi Received on Thu Nov 06 2003 - 15:45:54 CET