Query optimizing

Question

I was wondering if i can get input from anyone in optimizing this query. any input appreciated
select a.alignment_name, a.external_id_1, a1.alignment_name, c1.name, c1.external_id_1, af.affiliation_type, c2.name, c2.first_name, c2.external_id_1
from alignment a, customer_alignment ca, customer_rating cr, affiliation af, customer c1, customer c2 , alignment a1
where a.team_id in (32236,32266) and a.status = 'ACTV' and ca.alignment_id = a.alignment_id
and cr.alignment_id = ca.alignment_id and cr.customer_id = ca.customer_id and cr.rep_ratings = '1'
and af.from_customer_id = cr.customer_id and c1.customer_id = af.to_customer_id
and c2.customer_id = af.from_customer_id and a1.alignment_id = a.manager_alignment_id
and af.from_customer_id <> af.to_customer_id and af.affiliation_type <> 'PRES' and af.affiliation_type <> 'INFL'
union
select a.alignment_name, a.external_id_1, a1.alignment_name, c1.name, c1.external_id_1, af2.affiliation_type, c2.name, c2.first_name, c2.external_id_1
from alignment a, customer_alignment ca, customer_rating cr, affiliation af, customer c1, customer c2 , alignment a1, affiliation af2
where a.team_id in (32236,32266) and a.status = 'ACTV' and ca.alignment_id = a.alignment_id
and cr.alignment_id = ca.alignment_id and cr.customer_id = ca.customer_id and cr.rep_ratings = '1'
and af.from_customer_id = cr.customer_id
and c1.customer_id = af2.to_customer_id
and c2.customer_id = af.from_customer_id and a1.alignment_id = a.manager_alignment_id
and af2.from_customer_id = af.to_customer_id and af2.affiliation_type <> af.affiliation_type
and af2.from_customer_id <> af2.to_customer_id
and af.from_customer_id <> af.to_customer_id and af.affiliation_type <> 'PRES' and af2.affiliation_type <> 'PRES'
and af.affiliation_type <> 'INFL' and af2.affiliation_type <> 'INFL'

Answer 1

As a first step
-- rephrase:
Select a.*
  from table1 a
where a.creation_date < v_CurDay3
   and not exists(select 1
                    from table2 e
                   where e.fum_id = a.fum_id
   and a.fum_id not in (select u.fum_id
                          from table1 u
                         where u.current_status = 'Cancelled'
                           and    u.last_chg > sysdate - 365);
-- to:
select *
  from (select x.*,y.fum_id fum_id_2
          from (select *
                  from table1
                 where creation_date < v_CurDay3
                   and (u.current_status <> 'Cancelled' or u.last_chg <= sysdate - 365)
               ) x,
               table2 y
         where x.fum_id = y.fum_id(+)
where fum_id_2 is null Regards
Etbin