For details see http://wiki.eclipse.org/EclipseLink/Examples/PolyglotPersistence

To run the examples:

1. run mvn to build the four modules
2. cd into the client folder
3. create the relational database with: java -classpath “target/*” example.CreateDatabase
4. run the example with: java -classpath “target/*” example.PolyglotDemo
5. reset both databases with: java -classpath “target/*” example.CleanDatabases