Re: SUPPORT FOR DECLARATIVE TRANSITION CONSTRAINTS

On Sep 20, 12:42 pm, paul c <toledobythe..._at_oohay.ac> wrote:
> On 20/09/2010 1:40 AM, Brian wrote:
> ...
>
> > Please go back to school and take an introductory course in logic.
>
> > Tuples are supposed to represent propositions.  Propositions refer to
> > objects in the universe of discourse.  In the context of database
> > updates, it is a gross oversimplification to assume that the universe
> > is nothing but a collection of arbitrary objects that are independent
> > of time....
>
> Actually, much, if not all, of db and computing in general depends on
> gross oversimplification, no matter that some theorists might prefer the
> more expensive word, abstraction.  But there's nothing gross about it if
> the resulting application is deemed useful.
>
> In the context of this particular application it's an out-of-context
> non-sequitur to mix up 'the universe' with 'universe of discourse', what
> I would call an act of high mysticism.  

Excuse me, but are you trying to say that propositions don't refer to objects in the universe of discourse?

<snip>

> All the original post shows is that it is possible to paint oneself into
> a corner with rigid preconceptions.  The supervisor doesn't need to
> muddle two different situations/relation values in one database
> transaction.  He could just as easily amend the 'first' work order in
> one transaction and amend the 'second' one in another transaction, or he
> could be provided with an interface to do that.  Nothing in the given
> schema relates or 'pairs' the two work order numbers. There might well
> be an application requirement that needs to be stated, for the
> supervisor to make such corrections.  In fact, given the stated
> requirements such as they are, there would be nothing illogical in the
> supervisor amending the 'second' one first and the 'first' one second or
> a different supervisor amending one or the other.

This is completely incoherent. To what exactly are you referring when you say that he could easily amend the 'first' work order in one transaction and amend the 'second' one in another. Are you saying that some constraints should be enforced by the application? That's what it sounds like you're saying. Received on Mon Sep 20 2010 - 21:44:06 CEST