-- explain4.txt

+----+-------------+----------+--------+------------------------------+----------------------+---------+------------------------+------+--------------------------+
| id | select_type | table    | type   | possible_keys                | key                  | key_len | ref                    | rows | Extra                    |
+----+-------------+----------+--------+------------------------------+----------------------+---------+------------------------+------+--------------------------+
|  1 | SIMPLE      | employee | ref    | PRIMARY,fk_employee_pay_type | fk_employee_pay_type | 2       | const                  | 40   | Using where; Using index |
|  1 | SIMPLE      | person   | eq_ref | PRIMARY                      | PRIMARY              | 5       | classfiles.employee.id | 1    |                          |
+----+-------------+----------+--------+------------------------------+----------------------+---------+------------------------+------+--------------------------+

MySQL predicts that using looking into the "fk_employee_pay_type" index with the provided pay type code will return the
addresses of 40 rows.  For each of those 40 rows, MySQL will go directly to each row to get the "employee" data, and then
use the "id" to look into the PRIMARY key of the "person" table.  MySQL predicts that each of these lookups will refer to
a single row, and MySQL will then go directly to that row to find the names to display.