oracle paging function

select row_.* from (select t.*,row_number() over (order by t.id) as num from t_person_info t
left join t_person_info d on t.id = d.id) row_  where num<= 500  and  num> 400


SELECT * FROM (SELECT ROWNUM AS rowno, t.*
        FROM t_person_info  t
        WHERE rownum <=500) table_alias
        WHERE table_alias.rowno >= 400