SQL server 2008r2
现在日常操作是查询gfdsa表内的数据按日期保存到另外一个表的（为了后面去重用）
现在查询一次需要1分钟左右，怎么才优化到30秒以内，或者有什么好的思路
use ccc
select t.*
from
(select aa,bb,cc,dd, row_number()
over (partition by bb order by bb desc)
rn
from (
select aa
=CONVERT(nvarchar(max),DECRYPTBYKEY(aa))
, bb ,cc ,dd from ccc..[gfdsa]except
select aa, bb ,cc ,dd from rfv..[qaw711]except
select aa, bb ,cc ,dd from rfv..[qaw712]except
select aa, bb ,cc ,dd from rfv..[qaeq717]except
select aa, bb ,cc ,dd from rfv..[qase702]except
select aa, bb ,cc ,dd from rfv..[qase703]except
select aa, bb ,cc ,dd from rfv..[qase704]except
select aa, bb ,cc ,dd from rfv..[qase705]except
select aa, bb ,cc ,dd from rfv..[qase708] except
select aa, bb ,cc ,dd from rfv..[qase709] except
select aa, bb ,cc ,dd from rfv..[qase710] except
select aa, bb ,cc ,dd from rfv..[qase711] except
select aa, bb ,cc ,dd from rfv..[qase716] except
select aa, bb ,cc ,dd from rfv..[qase718] except
select aa, bb ,cc ,dd from rfv..[qase719] except
select aa, bb ,cc ,dd from rfv..[qzew07yc] except
select aa, bb ,cc ,dd from rfv..[qzsew710]except
select aa, bb ,cc ,dd from rfv..[qzsew711]except
select aa, bb ,cc ,dd from rfv..[qzsew712]except
select aa, bb ,cc ,dd from rfv..[qzsew713]except
select aa, bb ,cc ,dd from rfv..[qzsew715]except
select aa, bb ,cc ,dd from rfv..[qzsew716]except
select aa, bb ,cc ,dd from rfv..[qzsew720]except
select aa, bb ,cc ,dd from tgb..[qzrdx713]except
select aa, bb ,cc ,dd from tgb..[qxdes711]except
select aa, bb ,cc ,dd from tgb..[qzxswa718]except
select aa, bb ,cc ,dd from tgb..[qxswaz711]except
select aa, bb ,cc ,dd from tgb..[qxswaz716]except
select aa, bb ,cc ,dd from tgb..[qxswzs711]except
select aa, bb ,cc ,dd from tgb..[qcdesx702]except
select aa, bb ,cc ,dd from tgb..[qwsxcsxz715]except
select aa, bb ,cc ,dd from tgb..[qwsxcsxz717]except
select aa, bb ,cc ,dd from tgb..[qtxdw709]except
select aa, bb ,cc ,dd from tgb..[qywsxa704]except
select aa, bb ,cc ,dd from tgb..[quwsx627]except
select aa, bb ,cc ,dd from tgb..[qixse708]except
select aa, bb ,cc ,dd from tgb..[qoxde715]except
select aa, bb ,cc ,dd from tgb..[qoxde716]except
select aa, bb ,cc ,dd from tgb..[qoxde717]except
select aa, bb ,cc ,dd from tgb..[qpswxa715]except
select aa, bb ,cc ,dd from yhn..[qlwsxe2]except
select aa, bb ,cc ,dd from yhn..[qkxdes718]except
select aa, bb ,cc ,dd from ujm..[qjxdre626]except
select aa, bb ,cc ,dd from ujm..[qhedxs710]except
select aa, bb ,cc ,dd from ujm..[qhedxs715]except
select aa, bb ,cc ,dd from ujm..[qhedxs717]except
select aa, bb ,cc ,dd from okm..[qhygvd718]except
select aa, bb ,cc ,dd from ijn..[qwsngf]except
select aa, bb ,cc ,dd from ijn..[qfwsxcd712]except
select aa, bb ,cc ,dd from ijn..[qfwsxcd715]except
select aa, bb ,cc ,dd from ijn..[wqaszx711]except
select aa, bb ,cc ,dd from ijn..[wsxcde709]except
select aa, bb ,cc ,dd from ijn..[wbgtfvd705]except
select aa, bb ,cc ,dd from ijn..[wsxaqzde710]except
select aa, bb ,cc ,dd from ijn..[wsxaqzde711]except
select aa, bb ,cc ,dd from ijn..[wsxaqzde719]except
select aa, bb ,cc ,dd from ijn..[wedcftv708]except
select aa, bb ,cc ,dd from ijn..[wedcftv715]except
select aa, bb ,cc ,dd from ijn..[eswqazxs710]except
select aa, bb ,cc ,dd from ijn..[esxwdcz627]except
select aa, bb ,cc ,dd from ijn..[rwsxcdeq705]except
select aa, bb ,cc ,dd from ijn..[rwsxcdeq708]except
select aa, bb ,cc ,dd from ijn..[rwsxcdeq708s?]except
select aa, bb ,cc ,dd from ijn..[rwsxcdeq709]except
select aa, bb ,cc ,dd from ijn..[rwsxcdeq711]except
select aa, bb ,cc ,dd from ijn..[rwsxcdeq712]except
select aa, bb ,cc ,dd from ijn..[rwsxcdeq713]except
select aa, bb ,cc ,dd from ijn..[rwsxcdeq716]except
select aa, bb ,cc ,dd from ijn..[rwsxcdeq718]except
select aa, bb ,cc ,dd from uhb..[tfrcvcde]except
select aa, bb ,cc ,dd from uhb..[ygbtrfvcd]except
select aa, bb ,cc ,dd from uhb..[uhnbecd712]
) as ss
) t
where rn<=1000 and
bb in('asd')
