如何优化下面这个sql语句，无从下手，各位大神谁知道，帮忙提点意见，小弟谢过了
select t.ACCT_NO acctNo,
t.USER_NO userNo,
t.OPEN_DATE openDate,
t.BAL bal,
t.PFREEZ_NUM pfreezNum,
t.FREEZ_AMT freezAmt,
m.MER_SOURCE merSource,
m.STATUS status,
m.MER_NAME merName,
p.PRDUCT_NAME productName,
p.PRODUCT_NO productNo,
i.INST_NAME instName,
p.CUST_TYPE custType,
i.INST_NO instNo,
item.ITEM_NO itemNo,
item.ITEM_NAME itemName,
t.ACCT_STATUS acctStatus,
t.ART_LOCKTYPE artLocktype,
t.LOCK_FLAG lockFlag,
t.LOST_FLAG lostFlag ,
t.FRZ_FLAG frzFlag ,
con.fee_name feeName ,
int.interest_name intName ,
t.int_calno intNo ,
t.managefee_no feeNo ,"
t.interest_flag intFlag
from T_ACT_MAST t
left join T_INST i on i.INST_NO = t.INST_NO
left join T_ITEM item on item.ITEM_NO = t.ITEM_NO
left join T_MER_INFO m on m.MER_NO = t.USER_NO
left join t_cal_interest int on int.interest_no = t.int_calno
left join t_fee_contrl con on con.fee_no = t.managefee_no
left join T_PRODUCT p on p.PRODUCT_NO = t.PRODUCT_NO