效率优化--并行和强制走索引

SELECT/*+parallel(T 16) parallel(B 16) parallel(D 16)*/
 T.POLICY_NO,
 T.DEPARTMENT_CODE,
 T.PLAN_CODE,
   FROM EPCIS_AUTO_POLICY_BASE_INFO T ,
       EPCIS_AUTO_POLICY_VEHICLE_INFO B,
       EPCIS_AUTO_A_PRE_MID_RESULT D
 WHERE T.POLICY_NO = B.POLICY_NO
   AND T.APPLY_POLICY_NO = D.APPLY_POLICY_NO(+)
   AND T.LAST_BEGIN_DATE >=
       ADD_MONTHS(TRUNC(TO_DATE(‘20151101‘, ‘YYYYMMDD‘), ‘YYYY‘), 9)
   AND T.LAST_BEGIN_DATE <
       LEAST(TO_DATE(‘20151201‘, ‘YYYYMMDD‘),
             ADD_MONTHS(TRUNC(TO_DATE(‘20151101‘, ‘YYYYMMDD‘), ‘YYYY‘), 12))
   AND T.UNDERWRITE_TIME < TO_DATE(‘20151201‘, ‘YYYYMMDD‘)

--强制走索引

seg是表的别名

/*+INDEX(SEG IDX_T_RES_ALLOSEG_ALLOID)*/