n which more than a single
    thread of control will be accessing the database at one time.  Even
    when Berkeley DB automatically handles database locking, it is normally
    possible for deadlock to occur.  Because the underlying database access
    methods may update multiple pages during a single Berkeley DB API call,
    deadlock is possible even when threads of control are making only
    single update calls into the database.  The exception to this rule is
    when all the threads of control acces