Question

我的查询执行时间太长，有谁知道如何优化下面的查询？附： 'temp_db'有1'024'912'779行。

以下是查询：

SELECT
    CASE 
       WHEN user_agent LIKE '%Mobile%' 
          THEN 'Mobile' 
          ELSE 'Desktop' 
    END AS DEVICE,
    CAST(DATEADD(hour, +8, timestamp_gmt) AS Date) AS HKDate,
    DATEPART(Hour, DATEADD(hour, +8, timestamp_gmt)) AS HKHour,
    pixel_name AS Pixel,
    COUNT(id) AS Fires,
    COUNT(DISTINCT id) AS Uu
FROM
    temp_db
WHERE
    CONVERT(date, timestamp_gmt) BETWEEN DATEADD(day, -3, GETDATE()) 
                                     AND CONVERT(date, GETDATE())
    AND advertiser_name LIKE '%TimCompany%'
GROUP BY
    CASE 
       WHEN user_agent LIKE '%Mobile%' 
          THEN 'Mobile' 
          ELSE 'Desktop' 
    END, 
    CAST(DATEADD(hour, +8, timestamp_gmt) AS Date),
    DATEPART(Hour, DATEADD(hour, +8, timestamp_gmt)),
    pixel_name;

Answer 1

试试这个：下面的脚本最小化重复的相同函数调用

SELECT DEVICE,
       HKDate,
       HKHour,
       Pixel
       COUNT(ID) Fires,
       COUNT(DISTINCT ID) Uu
FROM ( 
        SELECT
              CASE WHEN user_agent like '%Mobile%' THEN 'Mobile' ELSE 'Desktop' END AS DEVICE,
              CAST(DATEADD(hour,+8,timestamp_gmt) AS Date) AS HKDate,
              DATEPART(Hour,DATEADD(hour, +8, timestamp_gmt)) AS HKHour,
              pixel_name AS Pixel,
              ID
        FROM  temp_db
        WHERE  CONVERT(date,timestamp_gmt) BETWEEN DATEADD(day,-3,GETDATE()) AND CONVERT(date,GETDATE()) AND
       advertiser_name like '%TimCompany%'
)M
GROUP BY DEVICE,HKDATE,HKHOUR,pixel

Answer 2

where子句中的日期不是sargable。尝试以下：

SELECT
    CASE 
       WHEN user_agent LIKE '%Mobile%' 
          THEN 'Mobile' 
          ELSE 'Desktop' 
    END AS DEVICE,
    CAST(DATEADD(hour, +8, timestamp_gmt) AS Date) AS HKDate,
    DATEPART(Hour, DATEADD(hour, +8, timestamp_gmt)) AS HKHour,
    pixel_name AS Pixel,
    COUNT(id) AS Fires,
    COUNT(DISTINCT id) AS Uu
FROM
    temp_db
WHERE
    timestamp_gmt >= convert(date, DATEADD(day, -3, GETDATE()))
                 and timestamp_gmt < convert(date, DATEADD(day, 1, GETDATE()) )
    AND advertiser_name LIKE '%TimCompany%'
GROUP BY
    CASE 
       WHEN user_agent LIKE '%Mobile%' 
          THEN 'Mobile' 
          ELSE 'Desktop' 
    END, 
    CAST(DATEADD(hour, +8, timestamp_gmt) AS Date),
    DATEPART(Hour, DATEADD(hour, +8, timestamp_gmt)),
    pixel_name;

SQL Server查询帮助...超慢查询

2 个答案: