WITH room AS
(
SELECT 1 roomno, 2 col_, 4 row_ FROM dual
UNION ALL SELECT 2, 3, 4 FROM dual
UNION ALL SELECT 3, 2, 6 FROM dual
)
, person AS
(
SELECT '홍길동1' name, 10001 applyno FROM dual
UNION ALL SELECT '홍길동2' , 10002  FROM dual
UNION ALL SELECT '홍길동3' , 10003  FROM dual
UNION ALL SELECT '홍길동4' , 10004  FROM dual
UNION ALL SELECT '홍길동5' , 10005  FROM dual
UNION ALL SELECT '홍길동6' , 10006  FROM dual
UNION ALL SELECT '홍길동7' , 10007  FROM dual
UNION ALL SELECT '홍길동8' , 10008  FROM dual
UNION ALL SELECT '홍길동9' , 10009  FROM dual
UNION ALL SELECT '홍길동10', 10010  FROM dual
UNION ALL SELECT '홍길동11', 10011  FROM dual
UNION ALL SELECT '홍길동12', 10012  FROM dual
UNION ALL SELECT '홍길동13', 10013  FROM dual
UNION ALL SELECT '홍길동14', 10014  FROM dual
UNION ALL SELECT '홍길동15', 10015  FROM dual
UNION ALL SELECT '홍길동16', 10016  FROM dual
UNION ALL SELECT '홍길동17', 10017  FROM dual
UNION ALL SELECT '홍길동18', 10018  FROM dual
UNION ALL SELECT '홍길동19', 10019  FROM dual
UNION ALL SELECT '홍길동20', 10020  FROM dual
)
SELECT x.name
     , x.applyno
     , y.roomno
     , y.seat
  FROM (SELECT name
             , applyno
             , ROW_NUMBER() OVER(ORDER BY applyno) rn    -- 응시순서
--             , ROW_NUMBER() OVER(ORDER BY dbms_random.value) rn    -- 랜덤순서
          FROM person
        ) x
     , (SELECT roomno
             , seat
             , ROW_NUMBER() OVER(ORDER BY roomno, lv) rn
          FROM (SELECT a.roomno
                     , b.lv
                     , (MOD(b.lv - 1, a.col_) + 1) ||'_'|| CEIL(b.lv / a.col_) seat
                     , ROW_NUMBER() OVER(ORDER BY b.lv, a.roomno) rn
                  FROM room a
                     , (SELECT LEVEL lv FROM dual CONNECT BY LEVEL <= 99) b
                 WHERE b.lv <= a.col_ * a.row_
                )
         WHERE rn <= (SELECT COUNT(*) FROM person)
        ) y
 WHERE x.rn = y.rn
;

감사합니다. 복잡하게 생각했는데 의외로 간단히 푸시니..... 아직 마농님 수준에 미치지 못했나 봅니다. 존경합니다.