oracle删除重复记录

delete from cred_account ca1
where rowid < (select max(ca2.rowid)
                  from cred_account ca2
                 where ca1.certi_type_id = ca2.certi_type_id
                   and ca1.cred_num = ca2.cred_num
--                   and ca1.examiniee_id = ca2.examiniee_id
                   );