Re: row vs row.column level locking

Mladen Gogala wrote:
> On Sat, 17 Dec 2005 06:44:17 -0500, Mark C. Stock wrote:
>
> > technically speaking, if there's any FK-PK path between tables, columns are
> > related -- that's where the term 'relational' comes from. you're referring
> > to dependence/identity
>
> Actually, the term "relational" comes from "relational algebra",

Not quite. The name was suggested by Codd in his 1970 article "A Relational Model of Data for Large Shared Data Banks". His model is based on n-ary mathematical relations, hence the name.

> which is
> another name for the naive set theory

"Relational algebra" can in no way be used as a synonym for "the naive set theory". Relational algebra is a language whose expressive power is equivalent to that of the first-order logic.

>(excludes the axiom of choice,
> discussions of the cardinalities, well-ordering theorem, transfinite
> induction and Zorn's lemma).

It depends on what you mean by "naive" Halmos used the word to describe "axiomatic set theory from the naive point of view." His exposition certainly included AC.

>

That is what Ted Codd and Chris Date
> implemented and developed once upon a time in the galaxy of Milky Way.
>
> --
> http://www.mgogala.com
Received on Wed Dec 21 2005 - 09:00:26 CST