From: Jochen Theodorou <blackdrag@...>
Date: 2007-03-30T21:55:06+09:00
Subject: Re: Object/Relational Mapping is the Vietnam of Computer Sci

Sebastian Hanigk schrieb:
[...]
>>> As Austin already has mentioned, object modeling can be seen as a
>>> special form of ER modeling - which explains the plethora of
>>> dysfunctional and outright ugly object hierarchies one encounters in
>>> software engineering because those people do not understand the
>>> fundamental mathematics.
>> I don't agree with austin and the resulting ugly class hierarchy is
>> prove enough for me. Not in all cases of course ;)
> 
> Ah, I think I have been misunderstood: ugly object models are mostly
> produced by 損software engineers束 who have no knowledge about the
> fundamentals of ER modeling.

ER modeling is good when you want to store your objects in a database in 
the end, but that's all. Nearly any other more formal design method is 
as good as ER.

>> Why not consider OODB mathematics as part of graph theory and others?
> 
> There is no such thing as OODB mathematics in a usable, formal sense.

If I extend the relational algebra for the OO world and if I define all 
the basic functions the relational algebra does have, then I get a 
usable and formal expression. But not all that is usable for a 
mathematician is usable for real life.

bye blackdrag