加快 MSSQL SELECT DISTINCT 语句

Question

在我将DISTINCT 添加到SELECT 语句之前，我已经让这个查询正常工作并且不到1 秒。我试过GROUP BY，也试过MAX 每列。所有这些仍然提供相同的时间 5+ 秒。如果有人对如何加快运行速度有任何建议，我将不胜感激。

这是post here的后续内容

  SET @query = N'SELECT * FROM (  
  SELECT
        ROW_NUMBER() OVER (ORDER BY ' + @SORTBY + ') AS [rownum],  *  
  FROM (
        SELECT DISTINCT  
              dbo.funcSellIdByPropId(T0.id) as SellerId,  
              dbo.funcDefaultImage(T0.id, 1) as propImage,  
              dbo.funcDefaultImage(T0.id, 2) as propImage2,  
              dbo.funcDefaultImage(T0.id, 3) as propImage3,  
              dbo.funcDefaultImage(T0.id, 4) as propImage4,  
              dbo.funcCountPropertyImages(T0.id) as imageCount,  
              dbo.funcGetPropertyTypeListGB(T0.id) as TypeGB,  
              dbo.funcGetPropertyTypeListFR(T0.id) as TypeFR,  
              dbo.funcGetPropertyEnviListGB(T0.id) as EnviGB,  
              dbo.funcGetPropertyEnviListFR(T0.id) as EnviFR,  
              dbo.funcGetDepartmentByTown(T0.Town) as Department,  
              dbo.funcCheckFeaturedProperty(T0.id) as Featured,  
              T0.id, T0.Price, T0.BedRooms, T0.Town, T0.Postcode,
              T0.Mandate, T0.MinLandArea, T0.Rooms, T0.HabitableSurface, 
              T0.Active, T0.Budget,  
              T1.TitleFR, T1.TitleGB, SUBSTRING(T1.DescFR, 0, 300) as DescFR,
              SUBSTRING(T1.DescGB, 0, 300) as DescGB  
          FROM  
              PROPERTIES T0
              INNER JOIN PROPERTYTRANSLATIONS T1 ON T1.PropertyId = T0.id  
              INNER JOIN MATRIXPROPENVIRONMENT T2 ON T2.PropertyId = T0.id
              INNER JOIN ENVIRONMENT T3 ON T3.id = T2.EnvironmentId  
          WHERE  
              T0.Deleted = 0    
              AND T0.Active = 1   
              AND T3.GB IN (' + @FILTERBY + ')  
    ) T ) TT  
  WHERE  rownum BETWEEN (' + CONVERT(varchar(4), @PERPAGE * @PAGENUM) + ') AND (' + CONVERT(varchar(4), @PERPAGE * (@PAGENUM + 1)) + ')'

传递的参数

@PAGENUM = 0
@PERPAGE = 20
@SORTBY = N'Price DESC'
@FILTERBY = N'''City'', ''Village'', ''Coastal'''

结果

Download csv

Answer 1

在这里，正如 cmets 中所述，不会在所有内容上运行函数，只在您要返回的内容上运行：

更好的是，摆脱这些功能。 SQL 中的函数总是带有 DBA 的不良代码气味，他们还没有在集合中思考。我确信有一种更快的方法来获取这些值。

SELECT 
  [rownum],
  dbo.funcSellIdByPropId(T0.id) as SellerId,  
  dbo.funcDefaultImage(T0.id, 1) as propImage,  
  dbo.funcDefaultImage(T0.id, 2) as propImage2,  
  dbo.funcDefaultImage(T0.id, 3) as propImage3,  
  dbo.funcDefaultImage(T0.id, 4) as propImage4,  
  dbo.funcCountPropertyImages(T0.id) as imageCount,  
  dbo.funcGetPropertyTypeListGB(T0.id) as TypeGB,  
  dbo.funcGetPropertyTypeListFR(T0.id) as TypeFR,  
  dbo.funcGetPropertyEnviListGB(T0.id) as EnviGB,  
  dbo.funcGetPropertyEnviListFR(T0.id) as EnviFR,  
  dbo.funcGetDepartmentByTown(T0.Town) as Department,  
  dbo.funcCheckFeaturedProperty(T0.id) as Featured,  
  T0.id, T0.Price, T0.BedRooms, T0.Town, T0.Postcode,
  T0.Mandate, T0.MinLandArea, T0.Rooms, T0.HabitableSurface, 
  T0.Active, T0.Budget,  
  T1.TitleFR, T1.TitleGB, SUBSTRING(T1.DescFR, 0, 300) as DescFR,
  SUBSTRING(T1.DescGB, 0, 300) as DescGB  
  FROM  
(
 SELECT
        ROW_NUMBER() OVER (ORDER BY ' + @SORTBY + ') AS [rownum],  *  
 FROM (
        SELECT DISTINCT  
              T0.id

          FROM  
              PROPERTIES T0
              INNER JOIN PROPERTYTRANSLATIONS T1 ON T1.PropertyId = T0.id  
              INNER JOIN MATRIXPROPENVIRONMENT T2 ON T2.PropertyId = T0.id
              INNER JOIN ENVIRONMENT T3 ON T3.id = T2.EnvironmentId  
          WHERE  
              T0.Deleted = 0    
              AND T0.Active = 1   
              AND T3.GB IN (' + @FILTERBY + ')  
    ) T ) TT  
  WHERE  rownum BETWEEN (' + CONVERT(varchar(4), @PERPAGE * @PAGENUM) + ') 
    AND (' +   CONVERT(varchar(4), @PERPAGE * (@PAGENUM + 1)) + ')'
) TTT
JOIN PROPERTIES T0 ON T0.id = TTT.id
JOIN PROPERTYTRANSLATIONS T1 ON T1.PropertyId = T0.id