update GRADE_ASSESS_DETAIL_8
set (INDEX_VALUE_2, SCORE_2) =
(select nsxx.NSRZBZ, nsxx.NSRZBZ * 2.0
from (select t.nsrdzdah NSRDZAH,
t.nsrbm NSRSWJGDM,
t.nsrsbh NSRSBH,
t.nsrmc NSRMC,
tk.bfb NSRZBZ
from dj_nsrxx_8 t, dj_nsr_ks_8 tk
where t.nsrdzdah = tk.nsrdzdah) nsxx
where nsxx.NSRDZAH = GRADE_ASSESS_DETAIL_8.Nsr_File_No
and GRADE_ASSESS_DETAIL_8.INDEX_SCORE_ID_2 = 2)
------解决方案--------------------
数据量大的话应该做成临时表，
再对关联字段做索引，别贪图省事
------解决方案--------------------
且你这一层套一层，快不了啊
------解决方案--------------------
改成merge into试试