Hi all,

I am currently evaluating Hibernate to be used in a global corporate database in a highly clustered environment.

According to field study, Hibernate's overhead is about 10% compared to hand-coded JDBC.

But I would like to know more. My environment is:

1. Data movement about the same degree/frequency as amazon.com.
2. Highly clustered environment, deployed in global, strategic locations.
3. About 1000 queries (select queries) fired, per second.
4. Require subseconds response/queries completion.
5. Database is huge, terrabytes, going to pentas, with several hundreds of tables.

Our currently infrastructure and implementation already allowed us to do this. But we are thinking about refactoring our DAO code to use Hibernate.

My question to the Hibernate team is,
"Do you guys think Hibernate is ready for that?"

I asked this because I am happy with Hibernate after a successful POC. I've a genuine interest in the use of it.

Guys - what do you guys think? Is there any statistics or white papers, or other stuff that can support us?

As you said, there is not much overhead when using Hibernate in comparison to a pure JDBC approach.

The only thing ORMs (and Hibernate too) are notoriously bad at is mass operations (mass deletes, especially mass updates). Basically every point where you would not do object creation or loading in advance, an ORM might need to do so. So you should do such operations by plain JDBC most likely.

What I am quite confident of is that using Hibernate for other cases won't introduce more scalability problems than a plain JDBC solution would have.

This is a very appropriate application for the use of Hibernate together with some clustered caching solution. Hibernate can help move load away from the database and into the middle tier.

P.S. It makes a lot of sense to take advantage of our commercial consulting services for this kind of application, we can help you tune the caching and session management optimally for your performance requirements.

Thanks guys for the information.

Please kindly point me to previous (successful) implementation case study, and some of the established organization that is currently implementating Hibernate in the projects.

I do see IBM has a few articles talking about Hibernate+WSAD and Hibernate with Spring.

It's one of the more traditional company that I am working for. People here are quite preoccupied with the thinking that "open source" (that are not comercially supported) = sucks+will go away soon. I've shown them, with convincing evidence, that, this is not neccessarily true, with my recommendation and successful implementation of CVS, Eclipse, Junit.

Now it's the time for me to start to reengineer our DAO layer. Nothing revolutionize our data access group more than the the injection of an ORM. So I look forward to Hibernate. (I am not throughoutly convinced by TopLink)

Please kindly give me some help with your expert domain knowledge of Hibernate.

It takes quite a lot of effort to make an elephant dance.
My foremost thanks and with the warmest regards.