求大神帮我优化这个sql语句
select distinct userid from userlog where userid not in(select distinct userid from #user)
and accesstime >='2013-04-27' and accesstime<'2013-04-28';
怎么修改？ 现在效率太低
[解决办法]
select distinct userid
from userlog t
where
not exists(select userid from #user t1 where t.userid=t1.userid)
and accesstime >='2013-04-27' and accesstime<'2013-04-28';
