OpenJPA is built on sound architectural principles. Its core components communicate via well-designed interfaces and respects which layer of processing they belong. The object management kernel does not assume any specific nature of data storage system or user-level APIs.

Every major component of the architecture is pluggable.

Make minimal or no change to OpenJPA code. Make it user-friendly

Must get in-memory instances from different slices within the same persistence context. Loaded instance must remember which slice it originated from.

Who will manage the distributed transaction across the slices? OpenJPA runtime behaves more like a Resource Manager in distributed transaction i.e. it is a participant rather than a controller of transaction. It depends on external Transaction Manager to manage global transaction.

&homer;