This is one of the best computer books I have ever read. It gives a thourough description of the hibernate ORM tool and it gives a very good introduction into Object Relational Mapping in genereal.

Having said that, lets have a look at the book.

A lot can be found about the Paradigm mismatch. It has to do with the different appraoch of persisting data in a relational database and working with a domain object model in an object oriented programming language. This mismatch is discussed in the first chapter, together with some alternatives.

This chapter is a must read for every serious OO programmer and designer.

The second chapter discusses the first steps into Hibernate. It talks about the SessionFactory, queries, callback intefaces, etc. Then it discusses the configuration in managed and non-managed environments.

Then the first tough chapter about the mappings you can realize with hibernate (oops, there is even an advanced mapping chapter). Interesting to see and read about the different mapping principles you can have like, associations, class inheritence and fine grained versus course grained objects. Interesting discussion about object identity and mapping the domain model.

In chapter 4 your going through the CRUD methods of hibernate, you will learn about the persistence life cycle and some optimizations. A very important part is the fetch depth. How many objects are you going to store in your internal memory.

The next chapter deals with transactions and concurrency, of course these are very important. I liked the caching stuff better. This is where you can get your optimization. it is also one of the hardest parts to design. A lot of choices to be made, you need to understand your application.

Then we go into the advanced mapping topics. Mapping types, custom mapping types, collections. The discussions of 1 to multi and multi-multi associations is very extensive.

Chapter 7 deals with querying your data effectively. How to do pagination, use comparison operators, use joins and write report queries. This chapter contains to much to grasp at once. The introduction of this chapter allready states to use it when it comes a long. You will be reading this chapter more than once, I assure you.

The last two chapters are about writing Hibernate applications and about tools that can help you.

To my opinion this is a very good book, 5 stars at amazon for sure.