/*Write a query which is looking for the names of all employees whose salary is greater than 50% of their department’s
 total salary bill.
*/

    SELECT e1.first_name, e1.last_name   
    FROM employees e1   
    WHERE salary >   
    ( SELECT (SUM(salary))*.5   
    FROM employees e2   
    WHERE e1.department_id=e2.department_id);