Question

我有以下存储过程，它在没有返回总记录的情况下工作得很好，但是当我在单独查询中返回总记录时，它变得很慢。

还有另一种以更快的方式返回总记录的方法

视图

SELECT     dbo.tbl_ImagesMaster.ImgTitle, dbo.tbl_ImagesMaster.ImgID, dbo.tbl_ImagesMaster.ImgDate, dbo.tbl_ImagesMaster.ImgActive, 
                      dbo.tbl_ImagesMaster.ImgHits, dbo.aspnet_Users.UserName, dbo.tbl_ImagesMaster.ImgUserID, dbo.tbl_ImagesDetails.ImgDPath, 
                      dbo.tblUsersExtended.UAvatar, dbo.tbl_ImagesMaster.ImgRemarks
FROM         dbo.tbl_ImagesMaster INNER JOIN
                      dbo.aspnet_Users ON dbo.tbl_ImagesMaster.ImgUserID = dbo.aspnet_Users.UserId INNER JOIN
                      dbo.tbl_ImagesDetails ON dbo.tbl_ImagesMaster.ImgID = dbo.tbl_ImagesDetails.ImgDParentID INNER JOIN
                      dbo.tblUsersExtended ON dbo.aspnet_Users.UserId = dbo.tblUsersExtended.UUserID
WHERE     (dbo.tbl_ImagesDetails.ImgDDefault = 1)

THE SP

ALTER Procedure [dbo].[usp_searchImagestest] 

(
@CurrentPage As int=1,
@PageSize As int=10,
@searchType As int=1,
@Activeflag As bit=null,
@searchTerm as nvarchar(200),
@TotalRecords As int OUTPUT
)
As
begin
-- Turn off count return.
Set NoCount On


    --Full text search
    if @searchType=1
    begin
        select 
            ImgID,ImgTitle,ImgDate,imgHits,UserName,uavatar,RowRank
        from
            (Select
                ImgID,imgtitle,ImgDate,imghits,UserName,UAvatar
                , ROW_NUMBER() OVER (ORDER BY ImgID desc) AS RowRank
            From
                 vw_MasterImagesSearch
                WHERE FREETEXT(*, @searchTerm) and (@Activeflag IS NULL or ImgActive=@Activeflag)
            ) as MyImages
        where

            RowRank > (@PageSize * (@CurrentPage-1)) AND RowRank <= (@CurrentPage * @PageSize)

-- TOTAL RECORD, WHICH SLOW DOWN THE WHOLE SP EXECUTION
        select @TotalRecords = (select COUNT(*) From vw_MasterImagesSearch 
        WHERE FREETEXT(*, @searchTerm) and (@Activeflag IS NULL or ImgActive=@Activeflag))
    end

修改

我试过这个

查询1

select 
        ImgID,ImgTitle,ImgDate,imgHits,RowRank,TOTALCOUNT,
        (select username from aspnet_Users where UserId=MyImages.imguserid) as username,
        (select UAvatar from tblUsersExtended where UUserID=MyImages.imguserid) as Uavatar

    from
        (Select
            ImgID,imgtitle,ImgDate,imghits,ImgUserID
            , ROW_NUMBER() OVER (ORDER BY ImgID desc) AS RowRank
            ,COUNT(*) OVER() AS TOTALCOUNT
        From
             tbl_ImagesMaster
            WHERE FREETEXT(ImgTitle, @searchTerm) and (@Activeflag IS NULL or ImgActive=@Activeflag)
        ) as MyImages
    where

        RowRank > (@PageSize * (@CurrentPage-1)) AND RowRank <= (@CurrentPage * @PageSize)

查询2

    select 
        ImgID,ImgTitle,ImgDate,imgHits,RowRank,
        (select username from aspnet_Users where UserId=MyImages.imguserid) as username,
        (select UAvatar from tblUsersExtended where UUserID=MyImages.imguserid) as Uavatar

    from
        (Select
            ImgID,imgtitle,ImgDate,imghits,ImgUserID
            , ROW_NUMBER() OVER (ORDER BY ImgID desc) AS RowRank
        From
             tbl_ImagesMaster
            WHERE FREETEXT(ImgTitle, @searchTerm) and (@Activeflag IS NULL or ImgActive=@Activeflag)
        ) as MyImages
    where

        RowRank > (@PageSize * (@CurrentPage-1)) AND RowRank <= (@CurrentPage * @PageSize)

    select @TotalRecords = (select COUNT(*) From tbl_ImagesMaster
    WHERE FREETEXT(ImgTitle, @searchTerm) and (@Activeflag IS NULL or ImgActive=@Activeflag))

查询1耗时3秒查询2花了不到1秒

表中的总行数为100,000行

Answer 1

第二个选择再次运行搜索。只需更改您的分页搜索：

SELECT 
    ImgID,ImgTitle,ImgDate,imgHits,UserName,uavatar,RowRank, TOTALCOUNT
FROM
    (SELECT
        ImgID,
        imgtitle,
        ImgDate,
        imghits,
        UserName,
        UAvatar, 
        ROW_NUMBER() OVER (ORDER BY ImgID desc) AS RowRank
        COUNT(*) OVER() AS TOTALCOUNT
    FROM
         vw_MasterImagesSearch
        WHERE FREETEXT(*, @searchTerm) and (@Activeflag IS NULL or ImgActive=@Activeflag)
    ) as MyImages
WHERE
    RowRank > (@PageSize * (@CurrentPage-1)) AND RowRank



The line

COUNT(*) OVER() AS TOTALCOUNT

在分页发生之前给出内部SELECT的计数。

Answer 2

我认为应该在iKnowKungFoo解决方案中改变部分

ROW_NUMBER() OVER (ORDER BY ImgID desc) AS RowRank
COUNT(*) OVER() AS TOTALCOUNT

到

ROW_NUMBER() OVER (ORDER BY ImgID desc) AS RowRank
ROW_NUMBER() OVER (ORDER BY ImgID) AS TotalRows

所以第二部分应该包含 reverse 顺序。您可以阅读this answer和the article（需要注册到最后一个）。

无论如何，我个人会使用CTE而不是子查询。在这种方式中，您可以将所有行定义为主要集合作为CTE。您需要的只是执行一次获取COUNT(*)并另外获取所需的数据页面WHERE seq BETWEEN (@PageSize * (@CurrentPage-1)) AND (@CurrentPage * @PageSize)

另一种替代方案可以采用CROSS JOIN方式代替ROW_NUMBER() OVER (<reverse sort order>)（请参阅here）或UNION方法（请参阅here）。我建议你测试所有的方法，找到最合适的方法。

更新：我对CTE的意思是，可以更好地优化视图。首先，您可以尝试以下查询

WITH MasterImagesSearch AS (
    SELECT im.ImgTitle, im.ImgID, im.ImgDate, im.ImgActive,
           im.ImgHits, asp.UserName, im.ImgUserID, id.ImgDPath,
           e.UAvatar, im.ImgRemarks
    FROM dbo.tbl_ImagesMaster AS im INNER JOIN
           dbo.aspnet_Users AS asp ON im.ImgUserID = asp.UserId INNER JOIN
           dbo.tbl_ImagesDetails AS id ON im.ImgID = id.ImgDParentID INNER JOIN
           dbo.tblUsersExtended AS e ON asp.UserId = e.UUserID
    WHERE id .ImgDDefault = 1
), GetAll AS (
    SELECT ImgID,ImgTitle,ImgDate,imgHits,UserName,uavatar
    FROM MasterImagesSearch
    WHERE FREETEXT(ImgTitle, @searchTerm)
        AND (@Activeflag IS NULL or ImgActive=@Activeflag)
), MyImages AS (
    SELECT ImgID,imgtitle,ImgDate,imghitsUserName,uavatar
        ,ROW_NUMBER() OVER (ORDER BY ImgID desc) AS RowRank
        ,ROW_NUMBER() OVER (ORDER BY ImgID) AS TotalRows
    FROM GetAll
)
SELECT ImgID,imgtitle,ImgDate,imghitsUserName,uavatar
    ,RowRank + TotalRows -1 AS Total
FROM MyImages
WHERE RowRank BETWEEN (@PageSize * (@CurrentPage-1)) AND (@CurrentPage * @PageSize)

我没有进行任何额外的优化，但我使用CTE和INNER JOIN而不是子查询。

Answer 3

我认为当您使用存储过程通过参数获取查询结果时，SQL Server会为此SP生成执行计划，并为之后调用SP的每个SP使用此生成的执行计划。生成执行计划的有趣之处是表统计，SQL Server使用它们来生成最佳执行计划。如果您的SP的参数发生变化，则可能会生成执行计划无用且不是最佳执行计划。我认为每次想要使用whit defrence参数计算执行时间时都必须重新编译SP。此外，您可以使用SP中的内部参数，在每次运行SP时由SQL Server自动生成执行计划。例如，使用下面的代码：

ALTER Procedure [dbo].[usp_searchImagestest]
( 
  @CurrentPage As int=1, 
  @PageSize As int=10, 
  @searchType As int=1, 
  @Activeflag As bit=null, 
  @searchTerm as nvarchar(200), 
  @TotalRecords As int OUTPUT 
) 
As begin

Declare       
  @ICurrentPage int, 
  @IPageSize int, 
  @IsearchType int, 
  @IActiveflag bit,
  @IsearchTerm nvarchar(200), 
  @ITotalRecords int 

Set @ICurrentPage = @CurrentPage
Set @IPageSize = @PageSize
Set @IsearchType = @searchType
Set @IActiveflag = Activeflag
Set @IsearchTerm = searchTerm
Set @ITotalRecords = @TotalRecords

然后使用iternal参数代替SP参数。

搜索返回找到的总记录的存储过程非常慢

修改

3 个答案: