Performance issue when update AR_TRX_BAL_SUMMARY

Hi All,

EBS R12.1.3 PCP , 11g RAC 2nodes

i see one process running frequently taking 100% CPU and consuming more memory  with huge gets per exec,when i see associated Program with that session it is Workflow event and following is the Query running in background

"UPDATE AR_TRX_BAL_SUMMARY MAIN_SUM SET RECEIPTS_AT_RISK_VALUE = (SELECT SUM(DECODE(RAP.APPLIED_PAYMENT_SCHEDULE_ID, -2, 0, CRH.AMOUNT)) FROM AR_CASH_RECEIPTS_ALL CR, AR_CASH_RECEIPT_HISTORY_ALL CRH, AR_RECEIVABLE_APPLICATIONS_ALL RAP WHERE NVL(CR.CONFIRMED_FLAG, 'Y') = 'Y' AND CR.REVERSAL_DATE IS NULL AND CR.CASH_RECEIPT_ID = CRH.CASH_RECEIPT_ID AND CRH.CURRENT_RECORD_FLAG = 'Y' AND CRH.STATUS NOT IN ('REVERSED', DECODE(CRH.FACTOR_FLAG, 'Y', 'RISK_ELIMINATED', 'N', 'CLEARED')) AND CR.CASH_RECEIPT_ID = RAP.CASH_RECEIPT_ID AND RAP.APPLIED_PAYMENT_SCHEDULE_ID = -2 AND CR.PAY_FROM_CUSTOMER = MAIN_SUM.CUST_ACCOUNT_ID AND CR.CUSTOMER_SITE_USE_ID = DECODE(MAIN_SUM.SITE_USE_ID, -99, CR.CUSTOMER_SITE_USE_ID, MAIN_SUM.SITE_USE_ID) AND CR.ORG_ID = MAIN_SUM.ORG_ID AND CR.CURRENCY_CODE = MAIN_SUM.CURRENCY GROUP BY CR.PAY_FROM_CUSTOMER, CR.CUSTOMER_SITE_USE_ID, CR.CURRENCY_CODE, CR.ORG_ID), LAST_UPDATE_DATE = SYSDATE, LAST_UPDATED_BY = FND_GLOBAL.USER_ID, LAST_UPDATE_LOGIN= FND_GLOBAL.LOGIN_ID WHERE CUST_ACCOUNT_ID = :B4 AND SITE_USE_ID = :B3 AND CURRENCY = :B2 AND NVL(ORG_ID,