US Patent 7653628 Persistent data management with different isolation levels

A method is described for managing an application's cached persistent data with different isolation levels. The different isolation levels include: 1) requesting a lock for a first item of database data in response to the first item of database data not being cached and not yet having been used by the application; 2) requesting a lock for a second item of cached database data in response to the second item of database data being updated for a first time by the application; and, 3) requesting a lock for a third item of cached database data in response to it being confirmed that the third item of database data will need to be updated in its database.