Priority=integer

    Specifies the base priority of the monitor process. This priority
    should always be higher than the highest database user process
    priority.

    By default, the monitor runs at the highest interactive priority
    possible, 15. You should not normally have to lower the monitor
    process priority. If you change this to a lower priority, an
    attach operation can cause a deadlock. Deadlock occurs when
    multiple processes with higher priority than the monitor attempt
    to attach at the same time. In this case, the monitor must
    contend for CPU time with multiple higher-priority processes
    and is perpetually locked out. As a result, no one can use the
    database.