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Re: OODB query interface

On Fri, 11 Aug 2000, Jacob Martin wrote:
> >
> > >   Therefore, I suggest that the prime query language is the language of the
> > > API in an object oriented fashion, and that different graphical and natural
> > > language interfaces are implemented on top of that.
> >
> > I perfectly agree here.
> >
> > To be real object oriented the query interface has to provide a language
> > dependent API. This has to implement the query model (which we will have to
> > specify) into the underlying programming language. Front ends for that API may
> > be developed on top of that.
> >
> > >
> > >   But let's skip the skin and dive into the gore: what types of operation does it need to support?
> > >
> > >   I have come up with three kinds, two of which operates on sets (or bags) of objects, and one that operates on objects:
> > >
> > >   1) Normal set algebra on objects (joins etc)
> > >
> > >   2) Filtering, that is selecting subsets of objects that meet certain criteria (like WHERE clauses)
> >
> > Exactly. We need a way to define sets (subsets) of objects (filtering) and set
> > algebra functions to be used with these sets.
> >
> > >   3) Following references.
> > Why? Can you explain more?
> 
> I think he means:
> 
> Class A {
>     private B b_ref;
> }
> 
> Class B {
>     private int i;
> }
> 
> 
> select * from A where A.b_ref.i = 1
> 
> 
> Maybe?
Yes. I just wasn't sure how this fits into the S.O.D.A. model since there is no
"select X from Y where Z" in soda.

Anyway, a new mail list (http://www.egroups.com/group/oodb) has been started by
Carl to discuss all things regarding this new object query system
specification. Current working name of the specification is S.O.D.A - Simple
Object Database Access. Akmal Chaudhri, who some of you may know as one of the
OODBMS gurus today, has already joined the list. He will help with the
specification and build a bridge to the industry.

People, if you are interested in a query interface for ozone (and other
OODBMSs;), then subscribe the soda list and follow the discussion or, even
better, throw in your ideas. This would help to keep the S.O.D.A spec ozone
friendly and to start to implement the spec on a very early stage. Thus the
ozone implementation could be the reference implementation for Java. We, the
Ozone Database Project, have the chance to play an important role in the
S.O.D.A. development. 

I'm not totally sure if S.O.D.A is the right approach. We have to discuss this
further. However, _if_ we decide that we want to have S.O.D.A., then, of
course I need your help. 

What do you think?


Falko
-- 
______________________________________________________________________
Falko Braeutigam                              mailto:falko@smb-tec.com
SMB GmbH                                        http://www.smb-tec.com