Question

在我的SQL Server 2008 R2数据库中，我有一个调用函数的查询。

最近这个查询开始执行得非常慢。我发现用户定义的函数阻碍了所有查询。

我试图单独执行此功能，它需要40秒才能完成，而之前它在3-4秒内完成。所以我尝试执行函数内部的代码并在3-4秒内执行。

我无法理解为什么执行函数代码所花费的时间比调用函数本身要少得多。我只在SSMS中尝试过这一切。

这就是功能本身

ALTER FUNCTION [dbo].[fn_SI_GetMark] (@AREA_ID int, @BD datetime, @ED datetime)  
RETURNS decimal(24, 2) AS  
BEGIN 



Declare @mon int;
set @Mon = 1;
if(DateDiff(day, @BD, @ED) > 40)
begin

declare @q1sb datetime; set @q1sb = Convert(datetime, '01.01.'+Convert(nvarchar(4), Year(@BD)));
declare @q1eb datetime; set @q1eb = Convert(datetime, '01.04.'+Convert(nvarchar(4), Year(@BD)));
declare @q2sb datetime; set @q2sb = Convert(datetime, '01.04.'+Convert(nvarchar(4), Year(@BD)));
declare @q2eb datetime; set @q2eb = Convert(datetime, '01.07.'+Convert(nvarchar(4), Year(@BD)));
declare @q3sb datetime; set @q3sb = Convert(datetime, '01.07.'+Convert(nvarchar(4), Year(@BD)));
declare @q3eb datetime; set @q3eb = Convert(datetime, '01.10.'+Convert(nvarchar(4), Year(@BD)));
declare @q4sb datetime; set @q4sb = Convert(datetime, '01.10.'+Convert(nvarchar(4), Year(@BD)));
declare @q4eb datetime; set @q4eb = Convert(datetime, '01.01.'+(Convert(nvarchar(4), Year(@BD) + 1)));
if((@BD >= @q1sb) and (@BD < @q1eb))
begin
    set @BD = @q1sb;
end
else if((@BD >= @q2sb) and (@BD < @q2eb))
begin
    set @BD = @q2sb;
end
else if((@BD >= @q3sb) and (@BD < @q3eb))
begin
    set @BD = @q3sb;
end
else if((@BD >= @q4sb) and (@BD < @q4eb))
begin
    set @BD = @q4sb;
end



declare @q1se datetime; set @q1se = Convert(datetime, '01.01.'+Convert(nvarchar(4), Year(@ED)));
declare @q1ee datetime; set @q1ee = Convert(datetime, '01.04.'+Convert(nvarchar(4), Year(@ED)));
declare @q2se datetime; set @q2se = Convert(datetime, '01.04.'+Convert(nvarchar(4), Year(@ED)));
declare @q2ee datetime; set @q2ee = Convert(datetime, '01.07.'+Convert(nvarchar(4), Year(@ED)));
declare @q3se datetime; set @q3se = Convert(datetime, '01.07.'+Convert(nvarchar(4), Year(@ED)));
declare @q3ee datetime; set @q3ee = Convert(datetime, '01.10.'+Convert(nvarchar(4), Year(@ED)));
declare @q4se datetime; set @q4se = Convert(datetime, '01.10.'+Convert(nvarchar(4), Year(@ED)));
declare @q4ee datetime; set @q4ee = Convert(datetime, '01.01.'+(Convert(nvarchar(4), Year(@ED) + 1)));
if((@ED >= @q1se) and (@ED <= @q1ee))
begin
    set @ED = @q1ee;
end
else if((@ED >= @q2se) and (@ED <= @q2ee))
begin
    set @ED = @q2ee;
end
else if((@ED >= @q3se) and (@ED <= @q3ee))
begin
    set @ED = @q3ee;
end
else if((@ED >= @q4se) and (@ED <= @q4ee))
begin
    set @ED = @q4ee;
end


set @Mon = datediff(month, @BD, @ED) / 3;

end


declare @i int;

DECLARE @Mark decimal(24, 2); SET @Mark = 0;
declare @count int; SET @count = 0;

DECLARE @AREA_PATH nvarchar(max), @SI_CheckListId int, @SI_CheckListTitle nvarchar(max), @SI_CheckListCreatedBy int;


DECLARE @Mark2 decimal(24, 2); set @Mark2 = 0;
declare @count2 int; SET @count2 = 0;



DECLARE @areaIdStr nvarchar(max);
set @areaIdStr = convert(nvarchar(max), @AREA_ID);


DECLARE db_cursor_rights2 CURSOR
for
SELECT     tbl_SI_CheckList.SI_CheckListId
FROM         tblArea INNER JOIN
                  tbl_SI_CheckList ON tblArea.AREA_ID = tbl_SI_CheckList.AreaId
WHERE ('%/'+tblArea.AREA_PATH+'/%' like '%/'+@areaIdStr+'/%') 
and (((tbl_SI_CheckList.SI_CheckListIsDeleted <> 1) and (tbl_SI_CheckList.SI_CheckListDateCreated <= @ED))
    or  
    ((tbl_SI_CheckList.SI_CheckListIsDeleted = 1) and (tbl_SI_CheckList.SI_CheckListDateDeleted is not null) and (tbl_SI_CheckList.SI_CheckListDateDeleted >= @BD) and (tbl_SI_CheckList.SI_CheckListDateCreated <= @ED)))


OPEN db_cursor_rights2;  
FETCH NEXT FROM db_cursor_rights2
INTO @SI_CheckListId;
WHILE @@FETCH_STATUS = 0
BEGIN   


    set @i = 1
    while @i <= @Mon
    begin
        set @Mark2 = 0
        set @count2 = 0

        SELECT     @Mark2 = @Mark2 + Mark
        FROM       tbl_SI_CheckListRegistr
        WHERE     (SI_CheckListId = @SI_CheckListId) and ((tbl_SI_CheckListRegistr.DateCreated >= @BD) and (tbl_SI_CheckListRegistr.DateCreated < @ED) and (tbl_SI_CheckListRegistr.IsDeleted <> 1))

        if(@Mark2 is not null)
        begin 
            set @Mark = @Mark + @Mark2;
        end
        set @i = @i + 1;    

        SELECT     @count2 = count(Mark)
        FROM       tbl_SI_CheckListRegistr
        WHERE     (SI_CheckListId = @SI_CheckListId) and ((tbl_SI_CheckListRegistr.DateCreated >= @BD) and (tbl_SI_CheckListRegistr.DateCreated < @ED) and (tbl_SI_CheckListRegistr.IsDeleted <> 1))

        if(@count2 = 0)
        begin 
            set @count2 = @count2 + 1;
        end 

        set @count = @count + @count2;      

    end

    FETCH NEXT FROM db_cursor_rights2
    INTO @SI_CheckListId;

END
CLOSE db_cursor_rights2;
DEALLOCATE db_cursor_rights2;

if(@count = 0)
begin
set @count = 1;
end

set @Mark = round(@Mark/@count, 2)

RETURN (@Mark)


END

这就是我试图称呼它的方式

DECLARE @AREA_ID int; SET @AREA_ID=1;
DECLARE @BD datetime, @ED datetime;
SET @BD=cast('2012-10-01' AS DATETIME);
SET @ED=cast('2012-11-01' AS DATETIME);
DECLARE @MArk decimal(24,2);
set @Mark = (select dbo.fn_SI_GetMark(@AREA_ID, @BD, @ED));
PRINT @Mark

另外一件事，我试图在另一个dbserver上执行此功能（这两个服务器之间设置了复制）并且执行速度非常快。另外一个观察，如果我调用没有参数的函数，直接在函数中设置它们，它也可以快速执行。

Answer 1

可能是旧统计数据。尝试更新

UPDATE STATISTICS tbl_SI_CheckListRegistr
UPDATE STATISTICS tblArea
UPDATE STATISTICS tbl_SI_CheckList

Answer 2

功能尚未编译，并且没有以最佳执行计划运行。尝试重新编译功能以提高性能。

RECOMPILE：强制在之后编译，使用和丢弃新计划模块被执行。如果存在现有的查询计划模块，这个计划仍然在缓存中。

请参阅sp_recompile：

sp_recompile [ @objname = ] 'object'

为什么调用函数比直接执行函数代码需要更多的时间

2 个答案: