WITH T ( V1 , V2 , V3 , CNT ,RN )  AS (
 SELECT '컴퓨터' , 'pc'    , 'cpu'   , 1 , 1 FROM DUAL UNION ALL
 SELECT '컴퓨터'	, 'pc'	  , 'ram'   , 2 , 2 FROM DUAL UNION ALL
 SELECT '컴퓨터' , '모니터' ,	'hdmi'  , 1 , 3 FROM DUAL UNION ALL
 SELECT '자동차'	, '엔진'   ,	'휘발유' , 1 , 4 FROM DUAL UNION ALL
 SELECT '자동차'	, '엔진'	  , '디젤'	, 1 , 5 FROM DUAL 
 )

          
 SELECT LPAD(CODE, LENGTH(CODE) + LEVEL*4-1 ,' ')  "구분" ,  CNT "수량"
   FROM  (SELECT V1 CODE , NULL UP_CODE , NULL CNT ,MIN(RN) RN  FROM T GROUP BY V1
           UNION ALL
          SELECT V2 , V1 , NULL  , MIN(RN)  FROM T  GROUP BY V1 , V2
           UNION ALL
          SELECT V3 , V2  , CNT , RN FROM T 
         )
  START WITH UP_CODE IS NULL
  CONNECT BY PRIOR CODE = UP_CODE
  ORDER SIBLINGS BY RN   

WITH t AS
(
SELECT  '컴퓨터' gb1, 'pc' gb2, 'cpu' gb3, 1 cnt FROM dual
UNION ALL SELECT '컴퓨터', 'pc'    , 'ram'   , 2 FROM dual
UNION ALL SELECT '컴퓨터', '모니터', 'hdmi'  , 1 FROM dual
UNION ALL SELECT '자동차', '엔진'  , '휘발유', 1 FROM dual
UNION ALL SELECT '자동차', '엔진'  , '디젤'  , 1 FROM dual
)
SELECT DECODE('', gb2, gb1, gb3, '  '||gb2, '    '||gb3) gb
     , SUM(cnt) cnt
  FROM t
 GROUP BY gb1, ROLLUP(gb2, gb3)
 ORDER BY gb1, gb2 NULLS FIRST, gb3 NULLS FIRST
;