select t1.emp_no,(t1.salary-t2.salary) as growth from (
(select emp_no,salary from salaries where to_date ='9999-01-01') as t1
inner join
(select s.* from employees as e inner join salaries as s on e.emp_no = s.emp_no
and e.hire_date = s.from_date) as t2
on t1.emp_no = t2.emp_no
) order by growth asc