Hi below is a query where certain set of data is fetched from a table based on certain condition, but the execution takes lot of time , is there a way we can optimize the code below


SELECT DISTINCT a.CNOTE_BOOK_ID , a.CNOTE_SERIES, a.AGENT_CODE, a.OPERATOR
FROM db2inst1.CNGC_B OOK a LEFT OUTER JOIN db2inst1.CNGC_N OTE b
ON a.CNOTE_BOOK_ID = b.CNOTE_BOOK_ID LEFT OUTER JOIN db2inst1.CMCN_S ERIES c
...