Re: Columns without names

dawn wrote:
> JOG wrote:
> > Faced with a data collection something like:
> > Tom is aged 20, Dick is aged 30 and Harry is aged 40
> >
> > I find it apt to view a relation predicate for them as:
> > "There is a people_relationship where name is X and age is Y"

I just see that I mis-read the question a bit.

Wouldn't it be more common to name the predicate people_relationship and have the predicate named people_relationship be: name x is age Y?

> > (Initially this was to stop any urge to think in terms of entities as
> > opposed to assertions, and even though this is now unnecessary the
> > process has stuck)
> >
> > However it struck me that this process may be reversed. Not very
> > interesting, until I started considering domain-defining statements
> > such as:
> >
> > "There is a number, 7." or "There is a letter, b."
> >
> > These are potentially different statements to those such as "There is a
> > person, Sally" because the latter is stating "There is a person where
> > name:Sally". The values held in the former assertions have no
> > discernable attribute name - rather than a tuple such as {
> > (name:Sally), (age:28)} I just have { (7) } or { (b) }.

"There is a number, 7" is analogous to "There is a name, Sally" Each statement is indicating a possible domain (numbers, names) and an element of that set. 7 is an element of numbers and Sally is an element of names.

> > So I would like to offer for discussion the concept of whether it is
> > possible to have a relation with a single column /but no column name/.
> > Granted it is kooky, but is there anything theoretically against this
> > principle, and if not, could it be of value?

I think you are asking about modeling the proposition "There is a number 7"

In this case, the relation, itself, might be named "number" and its domain could be a subset of numbers. So, then the entire proposition is modeled with the relation set being the domain for the attribute values.

I think you have a point here, although I'm not sure I'm getting it yet. The entire proposition you are modeling can be modeled with a single attribute in a single relation and the relation provides the designation for the domain.

In order to conform to current relational theory, you would need to add in a redundant domain for the attribute as if that were different than the domain of the relation itself. Is that your point? --dawn Received on Sat Sep 16 2006 - 19:35:19 CEST