MYSQL Slow Query



我们的Java应用程序运行得很慢。

出现这种情况的原因有很多,其中一个主要原因可能是应用程序中的MySQL代码使用两个不同的表来获取这些数据,进行连接。有没有人能够建议如何更好地编写此查询以提高性能?

SELECT DISTINCT uniqueId
FROM advertisementmodule
JOIN advertisement ON advertisementmodule.idAdvertisement = advertisement.idAdvertisement
JOIN advertisementschedule ON advertisement.idAdvertisementSchedule = advertisementschedule.idAdvertisementSchedule
JOIN adschedulegroup ON advertisementschedule.idAdScheduleGroup = adschedulegroup.idAdScheduleGroup
WHERE adschedulegroup.publisherCode = 'ABC';
SELECT *
FROM taurustour
JOIN searchthemestaurus
WHERE uniqueId IN (
        '18538'
        ,'17142'
        ,'11248'
        ,'18458'
        )
    AND air IS true;

uniqueId在哪个表中?

更具可读性:

SELECT  DISTINCT uniqueId
    FROM  advertisementmodule AS m 
    JOIN  advertisement AS a
          ON m.idAdvertisement = a.idAdvertisement
    JOIN  advertisementschedule AS s
          ON a.idAdvertisementSchedule = s.idAdvertisementSchedule
    JOIN  adschedulegroup AS g
          ON s.idAdScheduleGroup = g.idAdScheduleGroup
    WHERE  g.publisherCode = 'ABC'; 

您是否有以发布者代码开头的索引?

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