dw_bill_detail_full_yw表已建索引字段precinctname、paidYear、paidMonth、paidDay,
EXPLAIN select precinctname,paidYear,paidMonth,paidDay,sum(chargepaid) chargepaid
from dw_bill_detail_full_yw
GROUP BY precinctname,paidYear,paidMonth,paidDay
order by precinctname,paidYear,paidMonth,paidDay;
但是提示 Using temporary; Using filesort,需要怎么优化索引?