<code>
select first_name, 
       last_name,
       department_name,
       salary,
       dep_avg_sal
       from (
select department_id,
       first_name,
       last_name,
       salary,       
       round( avg(salary)
         over (partition by department_id) ) dep_avg_sal
  from employees 
) e join departments d
on e.department_id = d.department_id
where salary > dep_avg_sal
</code>