order by 导致索引选择错误
线上出现的慢SQL: SELECT c.id FROM fnbl_pim_contact AS c WHERE c.fuserid = 6246640 and (first_name !='' or middle_name is not null and middle_name !='' or last_name !='') AND c.status in ('N','U') order by id limit 1; 需要十多秒甚至更长时间才能出来结果。 这个表的大小...