Re: Decline of Science: Computer Science and Databases
Date: 3 Dec 2002 07:19:14 -0800
Message-ID: <e4330f45.0212030719.68f2221d_at_posting.google.com>
"Carl Rosenberger" <carl_at_db4o.com> wrote in message news:<as5gf4$u0n$07$1_at_news.t-online.com>...
> The "cheap trick" is called object orientation.
It is not object orientation. It is only a very bad use for some OO techniques.
> It uses "network style datadesign" all over to handle and modify
> data, not just for generating reports.
Then it is even worse.
Don't you know that the network data model was discarded several decades ago?
> All I wanted to show is
> that it's a pain to set up a simple query for a high level class in an
> inheritance hierarchy
A query for a class?
Something like: select * from Integer?
>, if your class structure is scattered across
> multiple tables.)
Something like this?:
var Types real relation { Name Char }
key { Name }
foreign key { Name } references Identifiers;
var SuperTypes real relation { Name Char, Parent Char }
key { Name, Parent }
foreign key { Name } references Types
foreign key { rename Parent as Name } references Types;
var PossReps real relation { Name Char, PossRepName Char }
key { Name, PossRepName }
foreign key { Name } references Types;
var PossRepComponents real relation
{ Name Char, PossRepName Char, ComponentName Char, TypeName Char }
key { Name, PossRepName, ComponentName } foreign key { Name, PossRepName } references PossReps;
> > Only unthinking hackers wants to store class hierarchies in a
> > database.
> Only unthinking theoreticians produce generalisations like this one.
Well, I meant the kind of class hierarchies you proposed.
I think storing a class hierarchy like:
shape | ellipse | circle
in a database could be a good idea.
> Your generalisation certainly is false for usecases where
> - a network model is used to hold data
Network models are totally obsolete.
> - only a hierarchical access path is necessary
Then you are talking about simple toys, not complex business applications.
> - time to market is essential
Then you should use a good SQL DBMS.
> - the class model may be constantly refactored and reducing
I don't think that class models like this:
shape | ellipse | circle
are very prone to be constantly refactored.
> maintenance work to do so is a must
A RDBMS would be very good for this.
> - navigation solves all issues perfectly and queries aren't needed
Again toy systems, but it is trivial to do it with a SQL DBMS and a RAD tool like Delphi, Oracle Forms or Visual Basic.
Regards,
Alfredo
Received on Tue Dec 03 2002 - 16:19:14 CET