select bb.dept_no,bb.emp_no,bb.salary from( select de.dept_no,de.emp_no,sa.salary,rank()over(partition by de.dept_no order by sa.salary desc) aa from dept_emp de join salaries sa on de.emp_no=sa.emp_no where de.to_date = '9999-01-01' AND sa.to_date = '9999-01-01' order by de.dept_no) bb where aa=1