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Re: some question about OODBMS,JDO,J2EE EJB

On Fri, 11 May 2001, SiYiYing wrote:
> ¿Õ°×I'm a newbie to OODBMS, and I have some question about OODBMS:

> 1.OODBMS like ozone provides an way to store normal java object to
> underlying storage, and support Transaction, XML etc.I think the 
 > Sun J2EE
> EJB container do the same thing.And they all use RMI to call ermote object's
> method, they all use proxy, and they achieve the same goal.

ozone and EJB have many important architecture features in common, indeed.
However, while EJB clearly focusses on supporting business applications, ozone
is better for more 'technical' apps like building a XML or RDF databases on top
or as basis of topic maps and things like that. Of course you can also use ozone
for business apps (like I do ;) but in most cases business apps have to deal
with RDBMS which is not possible with ozone, so EJB is better for that.

And, ozone is smaller and faster than EJB. The current ozone/XML code models
each XML DOM node as database object and let ordinary XPath processors like Xt
or Xalan work on top of it. Try this using EntityBeans... ;)

> 2.If OODBMS has had the ability to seperate business rule from underlying
> database persistent, Should we must use EJB container again?
 > If we should
> use , just because EJB is an standard,such as it can be integrated with
> Servlet,JSP?

Integrating ozone into an servlet environment is no problem. Anyway, if
EJB/J2EE meets the actual requirements of your app better than ozone, then of
course you should use it.

> 3.If in ClientDataBase(i think it is like Hsql's in-memory model) mode, is
> it just another "JDO"
 > some other:

The design and goals of JDO are totally different from ozones goals. IMO JDO
will become a more OO back-end for EJB containers. 

> .By now, I must start server at the same place with the cient, beacuse
> server need all the Impl class.Can you provide some depolyment tools, once the
> class is deployed,
 > server knows how to locate these class?

Yes, it's possible to improve the deployment of ozone apps. Are you ready to
help with this?

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