Austin Ziegler schrieb:
[...]
> Please, please, *please* read more about relational theory before you
> make statements like this, because it's technical nonsense. There *is*
> no "object model."

of course there is none as you define it. Who said I am using the same 
definition? Is your definition a common definition for "model" in 
general? If so please point me to a reference. I don't know all the 
correct UK/US terms used for this.

> Part of the problem, of course, is that a lot of terms are used and
> reused imprecisely.
 >
> 1. The Relational Model of Data is the combination of set theory and
>   relational algebra. There is no corresponding theory or mathematical
>   basis for object orientation. That is, there's no "Object Orientation
>   Model of Data".

never said something different, or?

>   Object orientation is, in fact, an implementation technique -- a
>   refinement of procedural programming that more tightly ties data with
>   operations related to that data.

I usually define what should be done and how to change the state, yes. 
How is that related to the problem?

>   That's an important point, too:
>   object orientation is about *programming*. It is not about data and
>   the storage of data.

I agree partially. It is a data structure, it is not more about 
programming as a binary tree is. So it is about structuring your data to 
fit your needs of computation... but that fits so much that is a useless 
statement

> 2. When *implementing* something, you will model the data. This can be
>   your data model that can be extended into an object model for
>   programming purposes. These "models" are better considered "schema";
>   they describe the layout of the data.

What you want to say is, that a schema is no model? Or at last not all 
schemata are models. I think.. I am not sure yet ;)

> Just because one *can* create something that works without a
> mathematical theory behind it does not mean that one *should* do so.

or should not do so.

> One
> certainly shouldn't claim that the thing without a mathematical theory
> behind it is superior to the thing with -- because that's something you
> should be able to demonstrate with, well, another theory. Performance
> metrics are not evidence of superiority of concept; just of
> implementation.

I have never done that. So I guess you don't mean me, because I am well 
aware of the problems of OODBs

>> And of course you can apply the theories of that area for that part of
>> the implementation.
>>
>> Why not consider OODB mathematics as part of graph theory and others?
> 
> There are no OODB mathematics, and that's part of the point that I've
> been trying to make.

ah, yes, ok.

> If you can point to OODB mathematics papers and
> theories, I'll retract or clarify that statement, but I have a
> reasonably high level of confidence that object orientation isn't
> expressed in terms of mathematics or theory the way that the relational
> model is.

ok, see "A Query Algebra for Object-Oriented Databases (1989)" on 
citeseer http://citeseer.ist.psu.edu/shaw89query.html

Found after searching 2 minutes in google. And 1989 isn't very new. The 
papers citing that paper are also quite interesting.

The nice thing in mathematics is, that I can use it to define very much 
things... even if they are useless in the end. I guess you should give 
more constraints.

> Sure, an object store can be set up to allow for smart loading and such,
> but that *doesn't* mean that it's a good idea. It might be the "right
> now" idea, but it is something you'll have to pay the piper for using at
> some point in the future.

depends on my goals, or not?

bye blackdrag