select a.id,

a.plan_num,

a.material_code,

a.material_desc,

a.unit,

a.con_num,

a.send_place,

a.ccz,

a.contract_num,

a.dcplan_sh,

a.plan_sendrq,

a.Shipper,

a.Shipper_tel,

a.dalei,

d.isDirect,

d.region,

e.supplier_name

from

delivery_plan a

left join (select order_num,order_row_num,supplier_name from material_china_order where document_date>='2022-01-01' and document_date<='2022-12-31') e

on a.pzbh=e.order_num

and a.pzhxm=e.order_row_num

left join ( select purchase_order_num,purchase_order_line_item_code,isDirect,region from material_china_plan where submission_date>='2022-01-01' and submission_date<='2022-12-31') d

on a.pzbh=d.purchase_order_num

and a.pzhxm=d.purchase_order_line_item_code

left join delivery_power b on a.dalei=b.qx

and a.zt='2'

and a.ccz='xxx' 

and b.czz='xxx' 

and b.code='80598231' 

order by plan_sendrq desc

如题，d和e中数据较多，现有一个这样的sql ，如何增加索引可以提升数据查询速度