+------------+-------------+------+-----+---------+-------+
| Field      | Type        | Null | Key | Default | Extra |
+------------+-------------+------+-----+---------+-------+
| client     | varchar(16) | NO   |     |         |       |
| channel    | varchar(16) | NO   |     |         |       |
| time_start | datetime    | NO   | MUL |         |       |
| time_end   | datetime    | NO   | MUL |         |       |
+------------+-------------+------+-----+---------+-------+
4 rows in set (0.20 sec)