Question: Find all the payment dates for the payments with an amount larger than 10 and the payments handled by a staff person with the first name Elsa.
SQL: SELECT payment_date FROM payment WHERE amount  >  10 UNION SELECT T1.payment_date FROM payment AS T1 JOIN staff AS T2 ON T1.staff_id  =  T2.staff_id WHERE T2.first_name  =  'Elsa'