select dept_no,emp_no,salary from (select *,dense_rank()over(partition by dept_no order by salary desc) rank1 from (select dept_no,dept_emp.emp_no,salary from dept_emp left join salaries on (dept_emp.emp_no = salaries.emp_no))t1)t1 where rank1 = 1
select dept_no,emp_no,salary from (select *,dense_rank()over(partition by dept_no order by salary desc) rank1 from (select dept_no,dept_emp.emp_no,salary from dept_emp left join salaries on (dept_emp.emp_no = salaries.emp_no))t1)t1 where rank1 = 1