select n.emp_no,(n.salary-t.start_salary) growth
from (select emp_no,salary from salaries where to_date = '9999-01-01') n
join (select e.emp_no,s.salary start_salary
    from employees e
    join salaries s 
    on e.emp_no = s.emp_no and e.hire_date = s.from_date) t
    on n.emp_no = t.emp_no
order by growth;