现在有两张表大约都是1万6千条左右 2张表left join 执行后大约27秒很慢 求优化select tt.id,tt.email,tt.mobilenum from (select t.id,t.email,t.mobilenum from tmp_table t) tt left join
(select u.id,u.email from hui_user u where u.meetid = 411) usr on tt.email = usr.email ;
(select u.id,u.email from hui_user u where u.meetid = 411) usr on tt.email = usr.email ;
select tt.id, tt.email, tt.mobilenum
from tmp_table tt, hui_user u
where tt.email = u.email(+)
and u.meetid = 411;
from tmp_table tt, hui_user u
where tt.email = u.email(+)
and u.meetid(+) = 411;