Need help to re-format the query

Question

Hi All,
Could any one please help me to rewrite this query or explain me how to do it as it is taking 20 mins to execute....
SELECT
AC.ACC_NO||DECODE(MI.MSG_CLASS,'ROF',(SELECT LMI2.PAYMENT_SET      
                                   FROM
        MIF LMI2 WHERE LMI2.MID =
        (SELECT CHILDMID FROM MFAMILY WHERE PARENTMID= MI.MID AND RELATION='ROF')),MI.PAYMENT_SET)||
        DECODE(MI.MSG_CLASS,'ROF', (SELECT LMI2.SERVICE FROM MIF LMI2 WHERE LMI2.MID = (SELECT CHILDMID FROM
  MFAMILY WHERE PARENTMID=MI.MID AND RELATION='ROF')),MI.SERVICE) HASH_KEY,
  MI.MID ,
  DECODE(MI.MSG_CLASS,'ROF',(SELECT LMI2.PAYMENT_SET FROM MIF LMI2
  WHERE LMI2.MID = (SELECT CHILDMID FROM MFAMILY WHERE PARENTMID=MI.MID AND
  RELATION='ROF')),MI.PAYMENT_SET) PAYMENT_SET,
  MI.AMOUNT,
  NVL(DECODE(MI.MSG_CLASS,'ROF',MI.CRAMOUNT, MI.DBAMOUNT) ,0) AMT,
  AC.ACC_NO,
  DECODE(MI.MSG_CLASS,'ROF',(SELECT LMI2.BATCH_COMPANY_CD FROM MIF LMI2 WHERE
  LMI2.MID = (SELECT CHILDMID FROM MFAMILY WHERE PARENTMID=MI.MID AND
  RELATION='ROF')),MI.BATCH_COMPANY_CD) BATCHCOMP,
  AC.ACC_ALIAS, NVL(AC.IBAN,
  NVL(AC.ACC_ALIAS,AC.ACC_NO)) IBAN_ACCNO,
  AC.CURRENCY , AC.ACCOUNTNAME ,
  CASE
       WHEN (SIGN(MI.PROCESS_DT - TO_DATE(:B2 ,'YYYYMMDD'))) = '1'
       THEN 'F'
       ELSE 'C' END FUTURE_IND,
       (CASE
            WHEN (MI.MSG_STATUS = 'CANCELED' OR   MI.STATBFHELD = 'CANCELED')
            THEN 'C'
            WHEN MI.BATCH_PAYMENT_TP = 'RMTRT'
            THEN 'R'
            WHEN (MI.REJECT_RETURN='REJT' OR MI.MSG_CLASS = 'ROF' OR MI.MSG_STATUS = 'REJECTED')
            THEN 'A'
            WHEN (MI.REJECT_RETURN='RETN' OR (MI.BATCH_PAYMENT_TP='RTACH' AND MSG_CLASS='ROF'))
            THEN 'B'
            WHEN  MI.MSG_STATUS='FORWARD_PROCESSING'
            THEN 'F'
            WHEN (MI.MSG_STATUS NOT IN  ('COMPLETE','CANCELED','REJECTED') OR (MI.MSG_STATUS='AGED' AND
                 MI.STATBFHELD NOT IN ('COMPLETE','CANCELED','REJECTED')) )
            THEN 'U'
            WHEN  MI.PROCESS_DT = TO_DATE(:B2 ,'YYYYMMDD')
            THEN 'P' END)
  PAY_STATUS,
  MT.DB_FEE_ACCOUNT_CCY,
  (SELECT MESSAGEFREETEXT.CONTENTS
       FROM
       MESSAGEFREETEXT
       WHERE
            FIELDNAME ='MANDATEREFERENCE'
                 AND MESSAGEFREETEXT.MID= MI.MID) MANDREF,
  (SELECT MESSAGEFREETEXT.CONTENTS
       FROM MESSAGEFREETEXT
       WHERE FIELDNAME ='DIRECT_DEBIT_REFERENCE' AND MESSAGEFREETEXT.MID=MI.MID)  DDREF,
  MT.CUSTOMER_BATCH_REFERENCE LOCINFO,
  (SELECT  MESSAGEFREETEXT.CONTENTS
       FROM MESSAGEFREETEXT WHERE FIELDNAME =  'SECOND_PARTY_ID' AND MESSAGEFREETEXT.MID=MI.MID) SECPRTYINF,
  (SELECT  MESSAGEFREETEXT.CONTENTS
       FROM MESSAGEFREETEXT WHERE FIELDNAME = 'HUB_PAY_PROD_TYP' AND MESSAGEFREETEXT.MID=MI.MID) PAYPRODTYP,
  DECODE(MI.MSG_CLASS,'ROF',(SELECT LMI2.CHANNEL_REFERENCE FROM MIF LMI2
                      WHERE LMI2.MID = (SELECT CHILDMID FROM MFAMILY WHERE PARENTMID=MI.MID AND
                                     RELATION='ROF')),MI.CHANNEL_REFERENCE) CHNREF,
  (SELECT  MESSAGEFREETEXT.CONTENTS
       FROM MESSAGEFREETEXT
       WHERE FIELDNAME =  'CHN_BATCH_REF' AND MESSAGEFREETEXT.MID=MI.MID) CHNBATREF,
  TO_CHAR(DECODE(MI.MSG_CLASS,'ROF',(SELECT LMI2.VALUE_DATE FROM MIF LMI2
                 WHERE LMI2.MID = (SELECT CHILDMID FROM MFAMILY WHERE PARENTMID=MI.MID AND
                                RELATION='ROF')),MI.VALUE_DATE),'DD/MM/YYYY') VALUEDT,
  DECODE(MI.MSG_CLASS,'ROF',(SELECT LMI2.ORIG_REFERENCE FROM MIF LMI2 WHERE LMI2.MID = (SELECT
                      CHILDMID FROM MFAMILY WHERE PARENTMID=MI.MID AND RELATION='ROF')),
                                                    MI.ORIG_REFERENCE) ORIGREF,
  CASE
       WHEN (MI.OFFICE <> MI.ORIG_OFFICE)
       THEN MT.DR_SIDE_RATE_AM
       ELSE
            CASE
                 WHEN MI.DBCURRENCY = MI.CRCURRENCY
                 THEN
                      CASE
                           WHEN MI.CRCURRENCY = :B4
                           THEN MT.DR_RATE ELSE MT.CR_RATE
                      END
                 ELSE
                      CASE
                           WHEN   MI.CRCURRENCY = :B4
                           THEN MT.DR_RATE ELSE MT.CR_RATE
                      END
            END
       END EXCHRT,
  MT.BBK_ADDR1,
  MT.BBK_ADDR2,
  MT.BBK_ADDR3 ,
  MT.BBK ,
  MT.BNF_ADDR1,
  MT.BNF_ADDR2,
  MT.BNF_ADDR3,
  MT.BNF_ADDR4 ,
  MT.BNF ,
  DECODE(MT.BNF_IDCODE,'AC',MT.BNF_ID,' ') ORGBNFID,
  DECODE(NVL(MI.ORIG_INSTRUCT_AMOUNT,0),0, MI.ORIG_AMOUNT) ORGINSTAMT,
  NVL(TRIM(MI.ORIG_INSTRUCT_CURRENCY),  MI.ORIG_CURRENCY) ORGINSTCUR,
  CASE
       WHEN MOP LIKE 'DRFT%'
       THEN 'DD'
       WHEN MOP   LIKE 'CHEQ%'
       THEN 'CO'
       WHEN MOP LIKE 'SWIFT'
       THEN 'TT'
       WHEN MOP LIKE 'DDP%'
       THEN 'T'
       WHEN MOP LIKE 'BOOK'
       THEN 'T' ELSE 'LP'
  END PYMTTP,
  MT.OBI ,
  TO_CHAR(MI.PROCESS_DT,'YYYYMMDD') PROCESSDT,
  MI.REFERENCE,
  MT.BBK_BIC,
  MT.BBK_IDCODE,
  DECODE(MT.BBK_IDCODE,'AC',' ',SUBSTR(MT.BBK_ID,1,12)) BBKID,
  MI.LOCAL_REF,
  MI.CURRENCY INDCURR,
  MI.MSG_STATUS,
  MI.PK_BATCH_SUBSET,
  TO_CHAR(SBBATCH.PROCESS_DT,'YYYYMMDD') SBPROCESSDT,
  DECODE(MI.MSG_CLASS,'ROF',MI.CRCURRENCY, MI.DBCURRENCY) DBCURR,
  MI.ORIG_REFERENCE ORIGREFRET
  FROM
       MIF MI,
       MTF1000 MT,
       ACCOUNTS AC,
       (     SELECT
                 MF.PK_BATCH_SUBSET,
                 MF.PROCESS_DT,
                 MTF.ORG_ID,
                 MTF.MP_CR_ACC,
                 MTF.CR_ACC_NO
            FROM
                 MIF MF,
                 MTF1000
                 MTF
            WHERE
                 ((MSG_STATUS IN ('COMPLETE','CANCELED','REJECTED')) OR
                 (MSG_STATUS = 'AGED' AND STATBFHELD IN ('COMPLETE','CANCELED','REJECTED')))
            AND
                 BATCH_MSG_TP = 'S' AND MF.MID = MTF.MID )
       SBBATCH
  WHERE
       MI.MSG_TYPE =   :B3
  AND MI.PROCESS_DT = TO_DATE(:B2 ,'YYYYMMDD')
  AND MI.BATCH_MSG_TP = 'I'
  AND DECODE(MI.MSG_CLASS,'ROF',
       (SELECT LMI2.SERVICE FROM MIF LMI2 WHERE LMI2.MID =
       (SELECT CHILDMID FROM MFAMILY WHERE PARENTMID=MI.MID AND RELATION='ROF')),MI.SERVICE)
       IN ('NET','HCN','BIB','LST','MRI')
  AND MI.PK_BATCH_EXCH IN (SELECT PK_BATCH_EXCH FROM BATCH_EXCH)
  AND MI.MID = MT.MID
  AND SBBATCH.PK_BATCH_SUBSET = MI.PK_BATCH_SUBSET
  AND TRIM(DECODE(MI.MSG_CLASS,'ROF',MT.CR_ACC_NO, NVL(MT.ORG_ID,NVL(MT.MP_DB_ACC,MT.ACC_NO))) )=AC.ACC_NO
  AND AC.OFFICE = :B1
  ORDER BY HASH_KEY,PAY_STATUS

Answer 1

Hi,
please try this.
The first decode or at least part of it repeats at least 7 times.
     DECODE(MI.MSG_CLASS,'ROF',
                                     (SELECT LMI2.PAYMENT_SET  
                                FROM MIF LMI2 WHERE LMI2.MID =
      (SELECT CHILDMID FROM MFAMILY WHERE PARENTMID=MI.MID AND RELATION='ROF')
                                        ),MI.PAYMENT_SET
               ||
    DECODE(MI.MSG_CLASS,'ROF',
                                     (SELECT LMI2.SERVICE
                                                                             FROM MIF LMI2 WHERE LMI2.MID =
               (SELECT CHILDMID FROM MFAMILY WHERE PARENTMID=MI.MID AND RELATION='ROF')
                                         ),MI.SERVICE) HASH_KEY,
is similar to this
select mif.* from mif, mfamily where mif.mid=mfamily.childmid
and relation = 'ROF' and msg_class='ROF'
insert it as an inline view and add a conditition
from ...
(select mif.* from mif, mfamily where mif.mid=mfamily.childmid
and relation = 'ROF' and msg_class='ROF') rof
Where ...
and mi.mid=Rof.mid (+)...
and your code above would look like
nvl(rof.payment_set,mi.payment_set) || nvl(rof.service,mi.service) HASH_KEY,
nvl(rof.payment_set,mi.payment_set) PAYMENT_SET
replace all the same decode above with corresponding nvl(...)Hope this helps.