WHERE子句中的函数 - 处理性能不佳

Question

我有一张超过100000条记录的大桌子。

我需要在用于评估总和的where子句中再添加一个条件，并仅返回总和<> 0的记录。

在这里使用吨连接和临时标签，我不打算发布它。

这是我的功能：

CREATE FUNCTION returnTotalSum(@clientID VARCHAR(20),@type INT,@currency VARCHAR(20),@date VARCHAR())

RETURNS INT
AS
BEGIN

DECLARE @totalSum BIGINT;

SET @totalSum = ( SELECT SUM (CONVERT(DECIMAL(18,4),P.iznos*(1-P.dp)/2))
                   FROM pts as p
                     INNER JOIN tippart t on p.tip = @type
                     INNER JOIN its i on p.partija = @clientID                      
                        WHERE p.currency = @currency and pts.dknizenja < @date
                GROUP BY p.partija )


RETURN @totalSum
END

我在这里使用它:(在WHERE子句中的最后一个AND）

... 
880001,
NULL, 
NULL,
NULL, 
NULL,
CONVERT(INT,REPLACE('2017.12.31','.',''))                 
            FROM ITS I WITH(NOLOCK)      
              JOIN TIPPART R WITH(NOLOCK) ON I.TIP = R.TIP       
              LEFT JOIN #UNPVT_TIPSTOPE_TS T (NOLOCK) ON I.KAMGRUPA = T.GRUPA AND I.TIP = T.TIP AND I.VALUTA = T.SIFVAL   
              LEFT JOIN #UNPVT_TIPSTOPE_TS T1 (NOLOCK) ON I.KAMGRUPA = T1.GRUPA AND I.TIP = T1.TIP AND I.VALUTA = T1.SIFVAL AND T.GRUPA IS NULL         
              LEFT JOIN #TMP_DODATNA_KS DS (NOLOCK) ON I.PARTIJA = DS.PARTIJA AND I.VALUTA = DS.SIFVAL AND I.KAMGRUPA = DS.GRUPA
              LEFT JOIN #NML_RATE N (NOLOCK)  ON I.TIP = N.TIP AND N.SIFVAL = I.VALUTA AND N.GRUPA = I.KAMGRUPA
             -- LEFT JOIN TIPSTOPE TS (NOLOCK) ON I.TIP = TS.TIP AND TS.GRUPA = I.KAMGRUPA AND TS.SIFVAL = I.VALUTA
              LEFT JOIN #NML_RATE_PERIOD NML (NOLOCK) ON I.TIP = NML.TIP AND I.VALUTA = NML.SIFVAL AND NML.GRUPA = I.KAMGRUPA AND NML.SIFVAL = I.VALUTA
             --WHERE NOT EXISTS (SELECT * FROM [dbo].[IC_INPT_AR_X_INT_RATE_SNPST] WHERE PARTIJA = I.PARTIJA AND VALUTA = I.VALUTA AND APP = 'ST')  
                  WHERE I.DOTVARANJE <= '2017.12.31'
                  AND (T.TIP IS NOT NULL 
                        OR T1.TIP IS NOT NULL 
                        OR DS.PARTIJA IS NOT NULL)
                        AND dbo.returnTotalSum(i.partija,r.tip,t.sifval,i.dotvaranje) <> 0

我认为这个问题是它必须通过每个记录，比较，评估条件。考虑到表中没有索引（我无法添加索引，因为我没有权限），它往往会永远运行。

有什么我可以做的来提高这个功能的性能，你有什么建议在功能旁边使用其他东西吗？

Answer 1

在您的实现中，调用该函数作为过滤的一部分，导致巨大的性能消耗，可能是由于多个索引扫描。

作为一般指导，如果你没有这个功能就可以做到这一点，你应该能够减少它。

没有数据结构和样本数据，很难为您提供准确的解决方案。

请尝试以下代码：

    ... 
    880001,
    NULL, 
    NULL,
    NULL, 
    NULL,
    CONVERT(INT,REPLACE('2017.12.31','.','')) 
    FROM ITS I WITH(NOLOCK)      
        JOIN TIPPART R WITH(NOLOCK) ON I.TIP = R.TIP       
        LEFT JOIN #UNPVT_TIPSTOPE_TS T (NOLOCK) ON I.KAMGRUPA = T.GRUPA AND I.TIP = T.TIP AND I.VALUTA = T.SIFVAL   
        LEFT JOIN #UNPVT_TIPSTOPE_TS T1 (NOLOCK) ON I.KAMGRUPA = T1.GRUPA AND I.TIP = T1.TIP AND I.VALUTA = T1.SIFVAL AND T.GRUPA IS NULL 
        LEFT JOIN #TMP_DODATNA_KS DS (NOLOCK) ON I.PARTIJA = DS.PARTIJA AND I.VALUTA = DS.SIFVAL AND I.KAMGRUPA = DS.GRUPA
        LEFT JOIN #NML_RATE N (NOLOCK)  ON I.TIP = N.TIP AND N.SIFVAL = I.VALUTA AND N.GRUPA = I.KAMGRUPA
        -- LEFT JOIN TIPSTOPE TS (NOLOCK) ON I.TIP = TS.TIP AND TS.GRUPA = I.KAMGRUPA AND TS.SIFVAL = I.VALUTA
        LEFT JOIN #NML_RATE_PERIOD NML (NOLOCK) ON I.TIP = NML.TIP AND I.VALUTA = NML.SIFVAL AND NML.GRUPA = I.KAMGRUPA AND NML.SIFVAL = I.VALUTA
        --WHERE NOT EXISTS (SELECT * FROM [dbo].[IC_INPT_AR_X_INT_RATE_SNPST] WHERE PARTIJA = I.PARTIJA AND VALUTA = I.VALUTA AND APP = 'ST')  
    LEFT OUTER JOIN -- Added this join with same logic from function rather than calling a function. 
    (
        SELECT SUM (CONVERT(DECIMAL(18,4),P.iznos*(1-P.dp)/2)) TotalSum
    FROM pts as p
        INNER JOIN tippart t on p.tip = r.tip
        INNER JOIN its i on p.partija = i.partija     
        WHERE p.currency = t.sifval and pts.dknizenja < i.dotvaranje
        GROUP BY p.partija 
    ) SumTable
    WHERE I.DOTVARANJE <= '2017.12.31'
    AND (T.TIP IS NOT NULL 
        OR T1.TIP IS NOT NULL 
        OR DS.PARTIJA IS NOT NULL)
        AND SumTable.TotalSum <> 0  -- This is similar to your old logic where you were comparing with function output. 

查询说明：

• 我已经在SumTable中添加了左外连接和现有的查询逻辑。
• 由于额外的左外连接由p.partija组成，它不会弄乱你的结果集。
• 旧函数的所有输入都已替换为相关值，因为我们在此处进行内联查询。
• 最后，表示作为性能消耗的罪魁祸首的部分被改进并且不会调用函数，而是使用SumTable.TotalSum并将其与0进行比较。

Answer 2

您的函数转换为内联表值函数应该接近这个。

CREATE FUNCTION returnTotalSum
(
    @clientID VARCHAR(20)
    ,@type INT
    ,@currency VARCHAR(20)
    ,@date VARCHAR(10) --Don't store dates as strings...
)
RETURNS TABLE AS RETURN

SELECT TotalSum = SUM(CONVERT(DECIMAL(18,4), P.iznos * (1 - P.dp) / 2))
FROM pts as p
INNER JOIN tippart t on p.tip = @type
INNER JOIN its i on p.partija = @clientID                      
WHERE p.currency = @currency 
    and pts.dknizenja < @date
GROUP BY p.partija