Re: Mixing OO and DB

On Feb 7, 12:35 pm, Victor Porton <por..._at_narod.ru> wrote:
> I know both object oriented programming and DB (SQL). But it seems
> that these are incompatible.

I suggest that OO ideas are too naive to continue influence programming. Formal Concept Analysis (FCA) is much more theoretically sound method how to organize things into taxonomies.

Here is an example -- a hierarchy of living things, restricted to the set {Lamprey, Trout, Lungfish, ..., Human}. FCA starts with feature matrix like this:

	           Jaws	Limbs	Hair	Lungs	Tail	Shell
Lamprey	0	0	0	0	1	0
Trout	            1	0	0	0	1	0
Lungfish	1	0	0	1	1	0
Turtle	            1	1	0	1	1	1
Cat	            1	1	1	1	1	0
Gorilla	            1	1	1	1	0	0
Human	            1	1	1	1	0	0

Then, the objects and the attributes (aka concepts) organize themselves into a lattice like this

Lamprey -> Trout -> Lungfish -> Cat -> Gorilla

                       |         |
                       |         ---> Human
                       |
                       ----> Turtle

which is more powerful concept than OO hierarchy of classes. Each FCA concept is essentially a limited form of a relation.

There are some reasons why FCA methods never enjoyed a success comparable to OO and Relational Model. They are simply more restrictive sets of relations which obey distributive property, why relations in general don't. Received on Thu Feb 07 2008 - 22:00:15 CET