Re: No exceptions?

From: paul c <>
Date: Thu, 29 Jun 2006 20:19:33 GMT
Message-ID: <pBWog.109359$IK3.48317_at_pd7tw1no>

J M Davitt wrote:
> paul c wrote:

>> Bob Badour wrote:
>> ...
>>> The way to avoid exceptions is to treat them as compile-time errors.
>> I take it you really mean "ONE way to avoid exceptions ...".  For one 
>> thing, I am interested in being able to express "x join y" in advance 
>> of defining a header for "x" (and I would like to evaluate it as well 
>> if that is logically possible!).
>> p

> This has me scratching my head. Without a heading, there can be no
> parameters. Without parameters, there can be no arguments. Without
> arguments, there can be no quantifiable proposition. Which leads me
> to, "A relation without a predicate is... What?" I find this
> especially curious because you mention the Closed World Assumption
> in the same post. (Don't forget the Excluded Middle!)
> So, Paul, what are you trying to explore?

Maybe instead of saying "defining a header", I should have said "in advance of entering a header". I had in mind that an "empty" header would be assumed.

My peculiar view doesn't require me to ask "what is the predicate of such and such a relation". This will sound ridiculous to most people I think because one would ask "well, what good is a database whose predicates we don't know?". OTOH, one aspect that for me defines a relational engine is precisely that it must not circumscribe even in the most indirect of ways what predicate a particular relation has, its whole value is in being to manipulate relations without knowing that - otherwise it would be an application!

Apologies if this is metaphysical mumbo-jumbo. Will ponder the CWA and excluded middle again.

p Received on Thu Jun 29 2006 - 22:19:33 CEST

Original text of this message