안녕하세요...적용기간 이력에 벗어난 자료를 찾으려고 하는데요..

WITH MST AS (  /* 적용기간 이력 */
SELECT 'AAA' CD, '20220101' STR_DY, '20220131' END_DY FROM DUAL UNION ALL
SELECT 'AAA' CD, '20220301' STR_DY, '20220331' END_DY FROM DUAL UNION ALL
SELECT 'AAA' CD, '20220401' STR_DY, '20220430' END_DY FROM DUAL
)
, LST AS (
SELECT 'AAA' CD, '20211220' DY FROM DUAL UNION ALL      /* 적용기간에 벗어남 */
SELECT 'AAA' CD, '20220118' DY FROM DUAL UNION ALL
SELECT 'AAA' CD, '20220220' DY FROM DUAL UNION ALL      /* 적용기간에 벗어남 */
SELECT 'AAA' CD, '20220415' DY FROM DUAL UNION ALL
SELECT 'AAA' CD, '20220501' DY FROM DUAL                /* 적용기간에 벗어남 */
)
SELECT * FROM (
    SELECT MAX(MST.MST_CNT) MST_CNT
         , LST.CD
         --, MST.STR_DY
         --, MST.END_DY
         , LST.DY
         , SUM(CASE WHEN LST.DY BETWEEN MST.STR_DY AND MST.END_DY THEN
                         0
                    ELSE 1
                END) VALID_CNT
      FROM (SELECT COUNT(CD) OVER(PARTITION BY CD) MST_CNT, CD, STR_DY, END_DY FROM MST) MST
         , LST
     WHERE LST.CD = MST.CD
     GROUP BY LST.CD, LST.DY
 )
 WHERE MST_CNT = VALID_CNT;

이렇게 해봤는데 좀더 좋은 방법 있을까요??