Want to improve the query performance

  SELECT PP.DESCR   FROM PS_P_PLAN_TBL PP

  WHERE PP.P_PLAN_ID = :1

        AND PP.EFFDT =

               (SELECT MAX (PP1.EFFDT)

                  FROM PS_P_PLAN_TBL PP1

                 WHERE     PP.BUSINESS_UNIT = PP1.BUSINESS_UNIT

                       AND PP.P_PLAN_ID = PP1.P_PLAN_ID

                      AND PP1.EFFDT <= :2)

 SELECT JJ.DESCR

   FROM PS_JOBCODE_TBL JJ

  WHERE JJ.SETID = 'SHARE' AND JJ.JOBCODE = :1

        AND JJ.EFFDT =

               (SELECT MAX (JJ1.EFFDT)

                  FROM PS_JOBCODE_TBL JJ1

                 WHERE     JJ.SETID = JJ1.SETID

                       AND JJ.JOBCODE = JJ1.JOBCODE

                      AND JJ1.EFFDT <= :2)