with t as (
select 'A001' id, '1' seq, 1000 qty from dual union all
select 'A001', '2', 999  from dual union all
select 'A001', '3', 900  from dual union all
select 'B001', '1', 500  from dual union all
select 'B001', '2', 550  from dual union all
select 'C001', '1', 750  from dual
), t1 as (
select 'A001' id, 'AAAA' name, 950 qty from dual union all
select 'B001', 'BBBB', 550 from dual union all
select 'C001', 'CCCC', 700 from dual
)
select b.id, b.name, a.last_qty, b.qty
     , decode(a.last_qty, b.qty, 'N', 'Y') gap
  from
      (select id
            , max(qty) keep (dense_rank last order by seq) last_qty
         from t
        group by id) a, t1 b
 where b.id = a.id

이렇게 빨리 답변해주실줄은....ㅜㅜ

지나가다님.....!!!!!

너무너무 감사합니다.