Re: By The Dawn's Normal Light

From: Bill H <wphaskett_at_THISISMUNGEDatt.net>
Date: Tue, 26 Oct 2004 20:12:56 GMT
Message-ID: <cdyfd.310369$MQ5.86568_at_attbi_s52>


Marshall:

"Marshall Spight" <mspight_at_dnai.com> wrote in message news:ZMxed.303809$D%.296516_at_attbi_s51...
> "Dawn M. Wolthuis" <dwolt_at_tincat-group.comREMOVE> wrote in message
news:clc0k2$ed1$1_at_news.netins.net...
> >
> > There are two types of collections -- "files" and "nested lists". The
> > nested lists may have one or more attribute types and zero to many
attribute
> > values. Whether the user cares about the ordering or not, the database
> > orders these, while the files are keyed, and therefore logically
ordered.
> > So, both top level structures (files) and their substructures are
logically
> > ordered.
>
> It's funny: the RM has no facilities for handling lists; the Pick model
> has no facilities for handling relations.

If I'm not mistaken the definition that started this thread was corrected to state:

"A relation is in 1NF if and only if all underlying domains contain atomic values only."

I must say, a "relation" certainly exists in the Nelson-Pick model. There are tremendous facilities to handle both "relations" and "lists".

> Sometimes you have ordered data, and sometimes you have unordered
> data. Which primitive operations you want depends on which one
> you have. Each model handles one well and ignores the other.

Everything I've seen in the Nelson-Pick model showed me there are facilities to handle ordered and unordered data and provide functions to move between "relations" and "lists". Their method reminds me of "piping" on other O/Ss: create a list and "pipe" each item to another process.

> I propose that the ideal model would handle both, and have
> relatively simple ways of transforming one into the other.
>
> Lists are simpler and sometimes therefore the better choice.
> Relations are more powerful, but that can mean more
> complexity than you need.

Jeeze, and to think, all I'm looking for is what works and doesn't take me 3 IT staff to keep it going. :-)

Bill Received on Tue Oct 26 2004 - 22:12:56 CEST

Original text of this message