def fetch_remote_data(db, data_length, uuids):
    """ Fetch VM data from the central DB.

    :param db: The database object.
     :type db: Database

    :param data_length: The length of data to fetch.
     :type data_length: int

    :param uuids: A list of VM UUIDs to fetch data for.
     :type uuids: list(str)

    :return: A dictionary of VM UUIDs and the corresponding data.
     :rtype: dict(str : list(int))
    """
    result = dict()
    for uuid in uuids:
        result[uuid] = db.select_cpu_mhz_for_vm(uuid, data_length)
    return result