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RE: ozone & modularity



On Mon, 05 Feb 2001, Jean-Marc VANEL wrote:
> -----Message d'origine-----
> De : Falko Braeutigam [mailto:falko@smb-tec.com]
> Envoyé : lundi 5 février 2001 12:27
> À : Jean-Marc Vanel; ozone-users@ozone-db.org; Jean-Marc VANEL
> Objet : Re: ozone & modularity
> 
> 
> Jean-Marc, Andreas and all, this gets more and more related to the ozone
> development. Should we take this to the ozone-dev list? (BTW: cross posting
> does
> not work)
> 
> OK for me, I just subscribed this morning.
> 
> 
> > > > The limitations of the current implementation should be listed.
> > > I agree. I will maintain this list. Just send your list of limitations
> and we
> > > will discuss about.
> > 
> > If ozone is to succeed, it must become more user-oriented. Listing current
> > limitations (and functionalities) is part of this.
> > - keeping all in memory during store of large object (see below)
> maybe I lost you here. Objects are always atomar.
> 
> Sorry for being obscure; what I meant is that "keeping all in memory during
> store of large object" is a limitation. Again a reference to my initial
> problem of not being able to store a big XML file with SAX.

I see. But this is a limitation of the DOM. There are to many references from
one node to the next, previous, parent, document, etc. If we decide to use DOM
as the underlying data structure for ozone/XML, then I guess we will always
face this problem.

> 
> 
> > - total number of objects < 2^32 , because of ObjectID used ; 
> not exactly true. 2^48 objects per ozone database node plus 2^16 nodes per
> cluster. (clusters are of course not yet implemented)
> 
> ====> not implemented? But there are Cluster and ClusterStrore classes in
> Package org.ozoneDB.core.wizardStore !?!

The WizardStore puts together several database objects into (database
object) clusters. In contrast, above I was talking about combinations of several
ozone servers into a cluster of servers. We decided to split up the object ID
from the beginning into 16 + 48bit to be able to exactly this. (sometime in the
future;)

> 
> 
> > > > Exploration of the code:
> > > >
> > > > org.ozoneDB.core.Env (environment of a ozone database server)
> > > > instanciates an object of interface:
> > > > org.ozoneDB.core.Store
> > > > which is implemented by:
> > > > org.ozoneDB.core.wizardStore.WizardStore
> > > > which is implemented by:
> > > > org.ozoneDB.core.wizardStore.ClusterStore
> > > ClusterStore does not implement anything
> > 
> > Yes, I just meant by this that WizardStore delegates its implementation to
> > ClusterStore, since it does :
> >  clusterStore = new ClusterStore( _env );
> 
> Yes, it does. WizardStore handles the ID table where ClusterStore deals with
> the actual clusters on disk. Again, is something wrong with this?
> 
> ====> No, nothing wrong; Falko don't worry, not evey post is a bug report !
phew! ;)


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