example of mysql explain output

mysql> explain wp_posts;
+-----------------------+---------------------+------+-----+---------------------+----------------+
| Field                 | Type                | Null | Key | Default             | Extra          |
+-----------------------+---------------------+------+-----+---------------------+----------------+
| ID                    | bigint(20) unsigned | NO   | PRI | NULL                | auto_increment |
| post_author           | bigint(20) unsigned | NO   | MUL | 0                   |                |
| post_date             | datetime            | NO   |     | 0000-00-00 00:00:00 |                |