Re: Concurrency in an RDB

On Dec 23, 10:49 pm, "David" <davi..._at_iinet.net.au> wrote:
> Marshall wrote:
> > David wrote:
>
> > > > Sigh. Regardless of the logical data model, a dbms is a formal logic
> > > > system. The folks who spend money to build databases expect some return
> > > > for their investment in the form of correct and useful answers.
>
> > > That's a good characterisation of an RDB. Not particularly relevant
> > > to a DB used to store the content for a newspaper.
>
> > While I am sore tempted to agree that newspapers run in a logic-free
> > environment, I cannot.
>
> > Why praytell are newspapers not in a position to benefit from
> > the relational model?
>
> I can imagine an extent over the submitted articles being useful, but
> not using the RM to represent the text itself.

Why not? Certainly that is not the way things are done now, but that doesn't really say much.

> Out of interest, do you see a benefit in representing a book
> relationally, assuming it is only comprised of hierarchical chapters of
> paragraphs of text?

Oh yeah. In a big way.

When I open J. Random Math book, I see that most everything in math can be built from a foundation of set theory. I have never run across a math book that builds all of mathematics out of trees or hierarchies. It seems unlikely given that trees cannot express many-to-many relationships.

Your particular example, a list of chapters each of which consists of a list of paragraphs, is an example of what I call a static hierarchy, which is something that the relational model handles particularly well.

And looking at an individual paragraph, what is that? It is a string, which is to say a sequence of characters, which is a map from the natural numbers to the target set characters, which is a relation. How would you go about representing the paragraph as a tree? A right-heavy binary tree of characters?

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Marshall Received on Sun Dec 24 2006 - 10:44:06 CET