#include <db.h> int DB_ENV->get_shm_key(DB_ENV *dbenv, long *shm_keyp);
            The DB_ENV->get_shm_key() method returns the base segment ID. This is used for Berkeley DB environment
            shared memory regions created in system memory on VxWorks or systems supporting X/Open-style shared memory
            interfaces. It may be specified using the DB_ENV->set_shm_key()
            method.
    
         The DB_ENV->get_shm_key() method may be called at any time during the
         life of the application.
    
         The DB_ENV->get_shm_key() 
            
                  method returns a non-zero error value on failure and 0 on success.