Active Responsibilities Report SQL Query

select application_name,responsibility_name,
security_group_name, user_name,
greatest(u.start_date, ur.start_date, r.start_date) start_date,
least(nvl(u.end_date, nvl(ur.end_date, r.end_date)),
nvl(ur.end_date, nvl(u.end_date, r.end_date)),
nvl(r.end_date, nvl(u.end_date, ur.end_date))) end_date
from fnd_user u,fnd_user_resp_groups ur,
fnd_responsibility_vl r,fnd_application_vl a,
fnd_security_groups_vl s
where a.application_id = r.application_id
and u.user_id = ur.user_id
and r.application_id = ur.responsibility_application_id
and r.responsibility_id = ur.responsibility_id
and ur.start_date <= sysdate
and nvl(ur.end_date, sysdate + 1) > sysdate
and u.start_date <= sysdate
and nvl(u.end_date, sysdate + 1) > sysdate
and r.start_date <= sysdate
and nvl(r.end_date, sysdate + 1) > sysdate
and ur.security_group_id = s.security_group_id
order by application_name,responsibility_name,security_group_name, user_name