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 JDO Expert Group <jdo-experts-ext@sun.com>
From: David Jordan <davejrdn@bellsouth.net>
Subject: Re: The Future of JDO
Date: Wed, 4 Oct 2006 22:19:39 -0400
To: Ilan Kirsh <kirsh@objectdb.com>

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An interesting proposal.
I continue to believe that the largest backers of JPA were against  
JDO because of it being binary compatible across object and  
relational databases. And due to the "bad blood" between JDO and EJB  
2.0. An issue with this approach is that the JPA group could continue  
to evolve JPA, making it difficult for the JDO group to produce such  
a superset. I have not done a thorough review of JPA, so I cannot  
comment on how feasible this is.

Another theory I had was that some of the relational vendors simply  
did not want there to be any standard for object persistence. By  
introducing JPA, we now have 3 competing APIs: Hibernate, JPA, and  
JDO. Most people I talk to these days seem to feel that neither JPA  
or JDO has achieved "industry standard status" and people continue to  
use and adopt Hibernate because it has the most market adoption.

It is very unfortunate we did not have JPOX for JDO 1.0. That would  
have given Hibernate more competition.

I am not advocating Hibernate, I have gotten requests from several  
companies recently that have had serious technical issues with  
Hibernate, struggling with problems that JDO does not have. But when  
I suggest they switch to JDO, they point out that JPA is the  
"standard", yet their impression is that no one is using it.

There is lots of confusion out there, most are deciding to not adopt  
any technology. Which is what I was concerned was one of the ulterior  
motives behind JPA.

On Oct 4, 2006, at 8:52 PM, Ilan Kirsh wrote:

> Hi all,
>
> The high traffic in the JDO mailing lists in the last days might  
> indicate that some implementations may join JPOX soon as JDO 2  
> compatible. This might be a good time to start a discussion on the  
> day after JDO 2.0. In my opinion in order to survive as live  
> technology and not end up like ODMG 3.0 - JDO 3.0 must extend JPA.  
> I think that as an extension to JPA there is a good chance that JDO  
> will be able to be attractive again to Java developers, even more  
> than it was in the good days 2-3 years ago.
>
> By visiting the forums in http://jdocentral.com these days or by  
> comparing "jdo" to "ejb3", "hibernate java", etc. inhttp:// 
> trends.google.com anyone can see that an urgent action is required  
> in order to save JDO. We do have some very important assets:  
> advanced technology, several good quality implementations, happy  
> users (not as much as we want but still something), the Apache  
> umbrella, the specification and the TCK, and of course Craig and  
> all the other wonderful people. Therefore, I believe that an action  
> now can bring JDO back to business.
>
> Probably most JDO vendors (that have not done so yet) will  
> implement JPA in the future. But I am not talking on saving vendors  
> but on saving JDO (even though it could also help the vendors  
> eventually). Sooner or later these vendors may focus their products  
> on JPA rather than on JDO that will remain behind. If, however, JDO  
> 3.0 will extend JPA in some way - we might be in a similar position  
> as Hibernate and Toplink that also support their old API in  
> addition to the new JPA API, with the advantage that our extensions  
> are standard and backed by multiple implementations including both  
> relational databases and object databases (plus some unique  
> powerful features such as JDO 2.0 fetch groups).
>
> Maybe some JPA issues can be excluded. But in my opinion at least  
> supporting the new API (e.g. deprecating makePersistent and adding  
> persist, or supporting both as in java.util.Vector since JDK 1.2)  
> is a must in order to survive. Maybe some support should even be  
> added in JDO 2.1. If this direction is accepted - rethinking might  
> also be required regarding the new support of Java 5.0 based JDO  
> annotations. I believe that even taking a decision in this  
> direction and publishing it - may change the momentum for JDO.
>
> Any comments will be welcomed.
>
> Regards,
>
> Ilan Kirsh
> ObjectDB Software
> http://www.objectdb.com
>
>


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