Re: Lookup Tables, the right way?

Frank Hamersley wrote:

> michael_at_preece.net wrote:
> > In the Pick environment you can use the Pick DBMS to persist data or
> > you can use the host OS's file system - or any other physical media,
> > including that accessible through a relational database. Sometimes it
> > makes sense to organise data into a two-dimensional matrix with, say,
> > columns represting one dimension and columns the other. Sometimes it
> > doesn't. The designer is free to choose whichever model is most
> > logical. A willingness to be constrained to a two-dimensional model is
> > what we call adherence to the illogical model.
>
> What makes you so sure it (the RM to be explicit) is two-dimensional?
>
> Cheers, Frank.

This is your ball-park, your level playing field, not mine, but...

Why do you need "nulls" to represent "missing values"? Isn't it because there can sometimes be no known value for a "cell", which we can think of as the intersection of a "column" (one dimension) and a "row" (t'other one)? In other words, every "n-dimensional tuple" (row) must have the same number of atomic values as every other "n-dimensional tuple" in the same table. Don't we then have a value to ascribe to "n"? Isn't "n" equal to the number of "columns"?

Mike.

Mike. Received on Wed Mar 15 2006 - 23:52:14 CET