Chapter 11. Advanced Topics

In the previous edition of this book, we warned readers that content in an "Advanced Topics" chapter might not line up with what every reader considered advanced. Our hypothesis was that the term advanced was quite subjective. It turned out to be more correct than we guessed, and we had people comment from both sides of the spectrum, saying either that it was not advanced enough or that there was too much to understand. It depended upon the background and experience of the developer as well as the complexity of application that was being developed.

What we can say is that, in large part, the topics in this chapter are those that we intended (during development of the specification) to be of a more advanced nature or to be used by more advanced developers. There are a few exceptions to this rule, though. For example, we included optimistic locking in this chapter even though most applications do need to be aware of and make use of optimistic locking. However, the actual locking calls are seldom used, and it just made sense to cover all the lock modes together. In general, we think that most applications will not use more than a few of the features described in this chapter. With this in mind, let's explore some of the other features of the Java Persistence API.