MySQL， 'WHERE NOT IN' 慢

Question

我遇到 MySQL 查询运行速度极慢的问题。每人需要10分钟以上。我尝试使用 LEFT JOINT 重写它，但“关节”不是我最好的专长))

希望有人能够帮助我。

    select subscriberId 
    from segments 
    where (segmentId = 29) 
    and subscriberId not in 
    (select subscriberId from que where (campaignId = 31 or campaignId = 32)) 
    order by rand() 
    limit 20000

所有索引均已就位。预先非常感谢。

Answer 1

尝试将 NOT IN 替换为 NOT EXISTS

select s.subscriberId 
from segments s
where (s.segmentId = 29) 
and NOT EXISTS (select * from que q 
                where s.subscriberId = q.subscriberId AND 
                (q.campaignId = 31 or q.campaignId = 32)) 
order by rand() 
limit 20000