with t as ( select '001' seq, '38' val from dual union all select '001' seq, '20' val from dual union all select '001' seq, '61' val from dual union all select '001' seq, '94' val from dual union all select '002' seq, '80' val from dual union all select '002' seq, '17' val from dual union all select '002' seq, '39' val from dual union all select '002' seq, '82' val from dual union all select '002' seq, '68' val from dual ) select seq, val from ( select row_number() over(partition by seq order by rownum) rn , seq, val from t ) where rn <= 2
2개씩 뽑는 기준은 따로 없는 건가요? 뭐.. val 크기순으로 2개라든지..