generates a filter for status==waiting and
    time older than lte_time

def waiting_filter(lte_time, conn=None):
    """
    generates a filter for status==waiting and
    time older than lte_time
    """
    if RBO.index_list().contains(IDX_OUTPUT_JOB_ID).run(conn):
        return (r.row[START_FIELD] <= lte_time)
    else:
        return ((r.row[STATUS_FIELD] == WAITING) &
            (r.row[START_FIELD] <= lte_time))