DB_PRIVATE |When an environment is opened with DB_PRIVATE, region memory would be allocated from the heap.
//DB_THREAD ; // Initialize transactionsThis is for multi-threaded, not for transaction.
Db* db = new Db( 0, 0 );//no dbenvThis db is not opened within the dbenv, so all the settings for the opened dbenv won't work for the db.
this discussion has been continue on this thread: https://forums.oracle.com/message/11194083#11194083
Thei appears to be an issue with the Windows System Cache. See thread: https://forums.oracle.com/thread/2571599