BIP – Query to extract Worker Grade, Grade Step and Rate value

select * from (
SELECT DISTINCT
papf.person_number,
paam.assignment_number,
pgf.name grade_name,
pgsf.name grade_step_name,
prv.value rate_value
FROM
PER_GRADES_F_tl PGF,
PER_GRADES_F PG,
PER_ALL_ASSIGNMENTS_M PAAM,
PER_ALL_PEOPLE_F PAPF,
PER_ASSIGN_GRADE_STEPS_F pagsf,
PER_GRADE_STEPS_F_TL PGSF ,
PER_RATE_VALUES_F prv
WHERE 
1=1
AND PG.grade_id = PGF.grade_id
AND PAAM.grade_id = PGF.grade_id
AND paam.person_id = papf.person_id
and paam.assignment_type = 'E'
and PGF.language = 'US'
AND TRUNC(SYSDATE) BETWEEN PAPF.effective_start_date AND PAPF.effective_end_date
AND TRUNC(SYSDATE) BETWEEN PAAM.effective_start_date AND PAAM.effective_end_date
AND TRUNC(SYSDATE) BETWEEN PGF.effective_start_date AND PGF.effective_end_date
AND TRUNC(SYSDATE) BETWEEN PG.effective_start_date AND PG.effective_end_date
AND pagsf.assignment_id (+) = paam.assignment_id
    and pagsf.grade_step_id = PGSF.grade_step_id (+)
	and paam.effective_start_date between pagsf.effective_start_date (+) and pagsf.effective_end_date (+)
	and paam.effective_start_date between PGSF.effective_start_date (+) and PGSF.effective_end_date (+)
	and PGSF.language (+) = 'US'
	and PGSF.grade_step_id = PRV.rate_object_id (+)
) a 
where grade_step_name is not null