Salary Change Query in Oracle HRMS/Payroll

select papf.employee_number,     

       papf.full_name,

       ppp_old.proposed_salary_n old_sal,

       ppp_new.proposed_salary_n new_sal,

       ppp_new.change_date

--,ppp_old.last_change_date,ppp_new.last_change_date

  from apps.per_all_people_f      papf,

       apps.per_all_assignments_f paaf,

       apps.per_pay_proposals     ppp_old,

       apps.per_pay_proposals     ppp_new

where 1 = 1

   and papf.person_id = paaf.person_id

   and paaf.assignment_type = 'E'

   and paaf.primary_flag = 'Y'

   and paaf.assignment_id = ppp_old.assignment_id

   and trunc(sysdate) between papf.effective_start_date and

       papf.effective_end_date

   and trunc(sysdate) between paaf.effective_start_date and

       paaf.effective_end_date

      --and ppp_new.change_date between trunc(sysdate) - 60 and trunc(sysdate)

      --and ppp_new.approved = 'Y'

   and ppp_new.assignment_id = paaf.assignment_id

   and ppp_new.last_change_date = ppp_old.change_date

   and ppp_new.change_date =

       (select max(x.change_date)

          from per_pay_proposals x

         where x.assignment_id = paaf.assignment_id)

   and paaf.assignment_id = 282416