What's the best OO-DBMS to use in Production for Java?

I was 开发者_开发问答thinking to start researching about OO-DBMS performance for Java applications to use in production scenarios. Did you have any successful experience using an OO-DBMS for Java rather than a RDMBS? If so, what dbms did you use?

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Nope. I have been unable to find any OO-DBMS which could be used. So our current solution uses Postgresql as sql database, and then Torque(http://db.apache.org/torque/) as an oo-mapper.

This has reduced the sql in our website code by around 90%, because torque automatic can handle most of the load/store of objects for me.

But I still have to write some sql when I need advanced queries from the database.

Oh and if you do find any OO-DBMS which can be used in production with java, please update this question with your result. I would like to use an OO-DBMS in your next project :}