Hibernate puzzlers

Hibernate is an elegant, straightforward, and easy to use library. This is undeniably true for simple domain models. What about more complex ones? It turns out that in case of complex domain models we usually run into interesting hibernate issues relating to performance or correctness.

Here, we will present several puzzles from hibernate and JPA to illustrate tricky use cases that have interesting side-effects, lead to incorrect behavior, or impose significant performance overhead. Come and see if you can solve them.