Re: Relational vs network vs hierarchic databases

Dawn wrote:

> Referring only to the structure, not the implementation, the way that
people
> think often aligns better with a graph model than a relation. This
says
> nothing about the implementation, but the high level view of the
data.

I agree, and furthermore a graph like the web lends itself to messy evolution (which was necessary to ensure any evolution in the case of the web). But data to support a business must also support consistency and efficient processing, not just people following the data in a way aligned with their thinking - that's what apps are for.

> If the implementation were identical, then yes, but a business whose
data
> model is based on a graph rather than a set of relations does just
fine.

Not really - why does Pick have files, then, rather than a single graph? And the Pick nested-list model is a rather limited and ridig form of a graph (I mean "degenerate" not in a derogatory sense). Why can't I have an element nested 2 lists deep, like a line item on an order, "point" to a top-level file like Customer?

> I've found the graphs to be far less rigid than relations, but still
haven't
> put my finger on why that is.

To use relational phrasing, that's because changing links between nodes effectively changes the predicate on which that node is based. That's fine, but that has logical consequences.

> I still suspect it has to do with the reasons
> why the web caught on -- it thinks something like people do.

Since AI imploded, I'm suspicious of attempts to make computers "think like" people. I'm especially suspicious given the Access databases end-users like to cook up...

> Back to
> reading -- I'm determined to learn enough that I can understand what
I have
> seen to be either a fluke or to be attributable to xyz.

The Watt book? If so, I'd recommend something by Luca Cardelli - he has plenty of online papers, and while he's a little formal, it's very readable.
> Cheers! --dawn

Not since the election, but thanks anyway.

• erk