我想优化我的查询，因为它需要更多时间来执行

Question

Select Distinct bs.COUP as couq
               ,TO_CHAR(ALLOTMENTDATE, 'DD-Mon-YYYY') as allotment
               ,bs.COUP as cou
               ,MODEL_YIELD as crisilBondYieldAsDouble
               ,round((TO_DATE(FINALDATE,'DD-MON-YYYY') -
                          TO_DATE(ALLOTMENTDATE, 'DD-MON-YYYY')) / 365, 2) as t
from MY_TABLE_NAME bs