Get namespace statistics for the period between start_offset and
        end_offset (inclusive)

def get_namespace_statistics(self, namespace, start_offset, end_offset):
        """Get namespace statistics for the period between start_offset and
        end_offset (inclusive)"""
        cursor = self.cursor
        cursor.execute('SELECT SUM(data_points), SUM(byte_count) '
                       'FROM gauged_statistics WHERE namespace = %s '
                       'AND offset BETWEEN %s AND %s',
                       (namespace, start_offset, end_offset))
        return [long(count or 0) for count in cursor.fetchone()]