title: how to tune this view?fetching time takes 9.968 but i want in .5. so how to give better performance
body: <pre><code>SELECT
  /*+ INDEX(ID_BL_REF_NO REF_number_BL_idx*/ DECODE(BL_TYPE,'E',BL_ORIGIN_NAME,'I',BL_FINAL_NAME) FROM_PORT,
   DECODE(BL_TYPE,'I',BL_ORIGIN_NAME,'E',BL_FINAL_NAME) TO_PORT,
  (BL_VESSEL_CONNECT||'/'||BL_VOYAGE_CONNECT||'/'||BL_PORT_CONNECT) Mother_vessel_voyage_port,
  SUM(BLC_SIZE) No_of_20s,
  SUM(BLC_SIZE)  No_of_40s,
  SUM(DECODE(BLC_SIZE,'20',1,'40',2)) Teus,
  SUM(BLC_GROSSWT) GrossWt,
  round((BLC_GROSSWT/SUM(DECODE(BLC_SIZE,'20',1,'40',2))),2) AverageWt,
  SUM(DECODE(BLF_MODE,'P',BLF_LOCAL_AMOUNT)) PREPAID,
  SUM(DECODE(BLF_MODE,'C',BLF_LOCAL_AMOUNT)) COLLECT,
  SUM(DECODE(BLF_MODE,'E',BLF_LOCAL_AMOUNT)) ELSEWHERE,
  (SUM(DECODE(BLF_MODE,'P',BLF_LOCAL_AMOUNT)+DECODE(BLF_MODE,'C',BLF_LOCAL_AMOUNT)+DECODE(BLF_MODE,'E',BLF_LOCAL_AMOUNT))/SUM(DECODE(BLC_SIZE,'20',1,'40',2))) AVERAGE
  FROM ID_BL_DETAILS,id_bl_containers,ID_BL_FREIGHT
  WHERE BL_REFNO=BLC_REFNO
  AND BLF_REFNO=BLC_REFNO
  GROUP BY BL_VESSEL_CONNECT,BL_VOYAGE_CONNECT,BL_PORT_CONNECT,BL_ORIGIN_NAME,BL_LODPORT,BL_DISPORT,BL_FINAL_NAME,BLC_GROSSWT,BL_TYPE
  </code></pre>