Thanks for replying to my earlier querry bout the book and also for advicing me on the EJBQL topic.
This is anothere querry about the book: As you said the EJB3 design do not need the earlier xml discriptors, may I ask you does the book not covers earlier EJB designs (as I will say) for backward compatibility?
Also, where can I get the proper discriptions/ references about these XML files? I tried searching the net and original sites but couldn't find the necessary get started like things with proper explanation about them.
EJB 3 makes descriptors optional but does not require it and it becomes the final source of truth. We discuss about descriptor in chapter 11 but the elements required for EJB 3. Similarly we provide a reference to descriptors in Appendix D.
You can find discussion about the descriptors in the EJB 2.1 spec. Here is the schema for EJB 2.1 version of ejb-jar.xml that fairly documents the elements