请问带in 和 子查询的sql语句怎么进行优化？

[PandaIT]

UPDATE user_bank_info set fisused = 2 where fuserid in (
SELECT userid FROM (
select DISTINCT ubi.fuserid as userid from customer as c JOIN user_bank_info as ubi ON c.fuserid =ubi.fuserid 
where ubi.faccountname <> c.fusername) as c)

数据库存的是百万级别的，请问怎么进行优化？

[LongRui888]

尽量把语句改成join的把，这样方便优化器生成更好的执行计划

[Rotel-刘志东]

优化子查询 select ubi.userid as userid from customer as c JOIN user_bank_info as ubi ON c.fuserid =ubi.fuserid where ubi.userid in(select 1 from user_bank_info as ubi where ubi.userid=c.fuserid )and ubi.faccountname<>c.fusername

[ACMAIN_CHM]

以文本方式贴出 explain select DISTINCT ubi.fuserid as userid from customer as c JOIN user_bank_info as ubi ON c.fuserid =ubi.fuserid where ubi.faccountname <> c.fusername 另外及所有表的 shoe index from