加速SQL Server存储过程

Question

我真的需要帮助加快SQL Server中的以下查询。 现在我把它作为一个视图，但我不在乎它是一个视图还是一个函数，我只需要它将记录集返回到MS Access接口。 查询需要11秒才能执行，但是通过它所经历的所有周期，我需要将其缩短到3秒或更短的时间。 我试图索引我现在的视图，但不幸的是，如果我要索引任何东西，我不能使用AVG函数或使用HAVING子句。

SELECT tblFi.fldFN
    ,tblFc.fldFC
    ,tblFc.fldCity
    ,tblFc.fldState
    ,tblFi.fldIN
    ,tblAPL.fldPK
    ,tblAPL.fldCI
    ,AVG(tblAPD.fldND) AS fldND
FROM tblAPD
INNER JOIN tblAPL ON tblAPD.fldLK = tblAPL.fldLID
INNER JOIN tblUA ON tblAPD.fldUAK = tblUA.fldUAID
INNER JOIN tblUL ON tblUA.fldULK = tblUL.fldULID
INNER JOIN tblFi ON tblUL.fldFK = tblFi.fldFID
INNER JOIN tblFc ON tblFi.fldFAC = tblFc.fldFacID
GROUP BY tblFi.fldFN
    ,tblFc.fldFac
    ,tblFc.fldCity
    ,tblFc.fldState
    ,tblFi.fldIN
    ,tblAPL.fldPK
    ,tblAPL.fldCI
    ,tblAPL.fldPG
    ,tblAPD.fldIG
HAVING (tblAPL.fldCI <> 0) 
AND (AVG(tblAPD.fldND) IS NOT NULL) 
AND (tblAPL.fldPG = 1) 
AND (tblAPD.fldIG = 0)

以下是表格（我只包括查询中引用的列的伪名称，然后fld1，fld2，fld3用于那些不相关的列）...

tblAPL - 450万行， fldLID聚簇索引

fldLID... INT
fld1... FLOAT
fldCI... FLOAT
fldPK... BIGINT
fldPG... TINYINT
fld2... TINYINT
fld3... TINYINT
fld4... NVARCHAR(15)
fld5... DATETIME
fld6... TINYINT
fld7... TINYINT

tblAPD - 1200万行， fldDID聚簇索引

fldND... FLOAT
fldLK... INT
fldUAK... INT
fldIG... TINYINT
fld1... SMALLINT
fld2... SMALLINT
fld3... SMALLINT
fld4... NVARCHAR(20)
fld5... TINYINT
fldDID... INT

tblUA - 850,000行， fldUAID聚簇索引

fldULK... INT
fldUAID... INT
fld1... NVARCHAR(10)
fld2... INT
fld3... NVARCHAR(15)
fld4... INT
fld5... TINYINT
fld6... NVARCHAR(10)
fld7... INT
fld8... TINYINT
fld9...TINYINT
fld10...TINYINT

tblUL - 200,000行， fldULID聚簇索引

fldULID... INT
fldFK... INT
fld1... INT
fld2... INT
fld3... INT
fld4... NVARCHAR(15)
fld5... DATETIME
fld6... DATETIME

Answer 1

您可以先添加SET NOCOUNT ON; 这应该会加快它的速度。

Answer 2

您是否尝试将HAVING子句更改为简单的WHERE子句？ 你真正无法移动到WHERE子句的唯一部分是第二行（带有AVG语句的那一行），对吗？ 这可能会加快速度，因为在生成整个结果集之前不会评估HAVING条件。

Answer 3

SELECT tblFi.fldFN
    ,tblFc.fldFC
    ,tblFc.fldCity
    ,tblFc.fldState
    ,tblFi.fldIN
    ,tblAPL.fldPK
    ,tblAPL.fldCI
    ,AVG(tblAPD.fldND) AS fldND
FROM tblAPD (NOLOCK)
INNER JOIN tblAPL (NOLOCK) ON tblAPD.fldLK = tblAPL.fldLID
INNER JOIN tblUA (NOLOCK) ON tblAPD.fldUAK = tblUA.fldUAID
INNER JOIN tblUL (NOLOCK) ON tblUA.fldULK = tblUL.fldULID
INNER JOIN tblFi (NOLOCK) ON tblUL.fldFK = tblFi.fldFID
INNER JOIN tblFc (NOLOCK) ON tblFi.fldFAC = tblFc.fldFacID
GROUP BY tblFi.fldFN
    ,tblFc.fldFac
    ,tblFc.fldCity
    ,tblFc.fldState
    ,tblFi.fldIN
    ,tblAPL.fldPK
    ,tblAPL.fldCI
    ,tblAPL.fldPG
    ,tblAPD.fldIG
WHERE (tblAPL.fldCI <> 0) 
AND (tblAPL.fldCI = 1) 
AND (tblAPD.fldIG = 0)
HAVING (AVG(tblAPD.fldND) IS NOT NULL)

创建一个非聚集索引（fldCI）和（fldIG）希望你有一个所有外键的索引。