Hibernate version: 3.2.5.GA

Cache provider : ehcache (read-write)

I recently have been trying to go from managing the caching of objects myself to let Hibernate's second-level cache take care of it, and I've noticed that the memory use goes up a lot.

I'm clearing the session cache, as recommended in "Java Persistence with Hibernate", 13.4.5, so I don't think that's the issue.

Could the increase be caused by the way Hibernate stores tuples instead of objects in memory? Some of my entities have a lot of primitive fields (bytes). They would take up a lot more memory if stored in Object format.