Greetings,

Since attending Gavin's BOF session at JavaOne and discovering that there is currently no planned JDO implementations for Hibernate, I was wondering if there were any independent Hibernate/JDO implementations in the works. Have you or anyone you know begun work on such a project? As members of the Hibernate community, do you feel a Hibernate/JDO implementation would be useful for your future needs? I would just like to get a good feel for the JDO sentiment.

Thanks,
Scott

The question, as I interpret it, is "Will hibernate become a standard or should hibernate join community standardization efforts?". The overwhelming response, atleast from most of my discussions, appears to be that Hibernate should participate in community efforts.

In that spirit, I would agree that a JDO implementation built on Hibernate would serve the community well. Obviously, any JDO effort at this point would be best served by focussing solely on the JDO 2 specification.

That said, I don't know where an effort like this can take place. Perhaps, the Hibernate team would like to work in conjunction with this effort or maybe the best place to do this is outside of Hibernate's CVS.

We are not interested much in any JDO effort. JDO2 is a subset of Hibernate 2.0.

We are working on the EJB 3.0 standardization effort.

What about those members of the community who are not developing within the confines of an EJB container? It would seem like supporting both standards (JDO 2.0 and EJB 3.0) would be the logical step for a widely-supported object/relational persistence service. Or are there reasons that dictate that JDO 2.0 and EJB 3.0 cannot co-exist?

Don't forget that JDO is an Object/WhatEver persistence specification.
Hibernate and EJB are Object/*Relational* persistence (implementation and) spec.

If supporting the two standards needed to be mutually exclusive, I could see the reasoning behind choosing EJB over JDO. But considering that there are ~20 JDO implementations that specifically support relational persistence, it would seem like supporting both would only make Hibernate a more versatile persistence solution...

This will be my last post, since it can become a flameware thread :).
Have a deep look at both Hibernate and the JDO 1.1 (and 2.0) specs, and you'll see the differences (usability, features, etc...).

PS: I know this is not an objective (technical) post, but it is very long to compare the 2 technologies and philosophies.

We will provide an EJB3 EntityManager that runs outside the EJB container. (And so will some other vendors.) We will also continue to provide (and improve) Hibernate.

Hey Gavin,

Thanks for the response....so, as far as the two specs are concerned (entity beans in EJB 3.0 and JDO 2.0), if both will be be able to run with or without an EJB container, what will be the primary usage for each standard? It seems there's a lot of confusion within the community regarding the boundaries of the two specs, and adding a version of the EntityManager that runs outside the EJB container probably makes that dividing line even fuzzier...