A lot of state is held at the SessionFactory level which in many systems causes the size of the SessionFactory in memory to be prohibitive. One option to help handle this would be to leverage proper caching via providers to allow overflow-to-storage, eviction, etc. This could be an extension to the RegionFactory spi to define new Region types for these various states.

Specific states that come to mind include:

• state in QueryPlanCache
• various state in EntityPersister impls

Anything that can be rebuilt given runtime information...