如何提高使用子查询时的查询性能

Question

查询的第一部分获取Policy的Premiums,Effective和Expiration日期。 第二部分创建Calendar，第三部分（最终SELECT声明）返回的收益细分为Month和Year 一切正常，只需3秒即可显示结果。 但后来我需要过滤什么PolicyNumber的工作，基本上我需要摆脱PolicyNumber的没有@ClassCode。因此，对于在查询的第一部分，我把WHERE条款：

WHERE State IN ('CA','NV','AZ')   
     AND PolicyNumber IN (
          SELECT PolicyNumber 
          FROM tblClassCodesPlazaCommercial 
          GROUP BY PolicyNumber 
          HAVING COUNT (CASE WHEN ClassCode NOT IN (@ClassCode)                  
THEN 1 END)=0 
          ) 

Thanksful到@Prdp用户我有这样的说法：Case语句将产生1对存在于列表中其他NULL将是ClassCode产生。现在，每个PolicyNumber的计数聚合将计为1。通过设置= 0，我们可以确保PolicyNumber在给定列表中没有任何ClassCode。

查询永久性后，在SSRS报告中可以有多于的200 ClassCodes。

有趣的是，这两个语句单独工作正常。但是，当我使用它们在一起（这是摆在cte policy_dataWHERE条款则执行需要永远。 是没有办法告诉引擎进行查询，这是

; WITH Earned_to_date AS (
    SELECT Cast(EOMONTH (GETDATE(), -1) AS DATE) AS Earned_to_date 
), policy_data AS (
    SELECT 
     PolicyNumber 
,  Cast(PolicyEffectiveDate AS DATE) AS PolicyEffectiveDate 
,  Cast(PolicyExpirationDate AS DATE) AS PolicyExpirationDate 
,  WrittenPremium 
,  State 
     FROM PlazaInsuranceWPDataSet 
     WHERE State IN ('CA','NV','AZ') 
    /* -------This statement gives me trouble ----------------------*/ 
     AND PolicyNumber IN (
          SELECT PolicyNumber 
          FROM tblClassCodesPlazaCommercial 
          GROUP BY PolicyNumber 
          HAVING COUNT (CASE WHEN ClassCode NOT IN (5151)                  
THEN 1 END)=0 
          ) 
) 

，然后计算和突破的第一部分下来收益只有那些已被过滤政策

我的整个代码如下：

; WITH Earned_to_date AS (
    SELECT Cast(EOMONTH (GETDATE(), -1) AS DATE) AS Earned_to_date 
), policy_data AS (
    SELECT 
     PolicyNumber 
,  Cast(PolicyEffectiveDate AS DATE) AS PolicyEffectiveDate 
,  Cast(PolicyExpirationDate AS DATE) AS PolicyExpirationDate 
,  WrittenPremium 
,  State 
     FROM PlazaInsuranceWPDataSet 
     WHERE State IN ('CA','NV','AZ') 
    /* -------This statement gives me trouble ----------------------*/ 
     AND PolicyNumber IN (
          SELECT PolicyNumber 
          FROM tblClassCodesPlazaCommercial 
          GROUP BY PolicyNumber 
          HAVING COUNT (CASE WHEN ClassCode NOT IN (@ClassCode)                  
THEN 1 END)=0 
          ) 
) 
, digits AS (
SELECT digit 
    FROM (VALUES (0), (1), (2), (3), (4) 
,  (5), (6), (7), (8), (9)) AS z2 (digit) 
), numbers AS (
SELECT 1000 * d4.digit + 100 * d3.digit + 10 * d2.digit + d1.digit AS number 
    FROM digits AS d1 
    CROSS JOIN digits AS d2 
    CROSS JOIN digits AS d3 
    CROSS JOIN digits AS d4 
), calendar AS (
SELECT 
    DateAdd(month, number, '1753-01-01') AS month_of 
, DateAdd(month, number, '1753-02-01') AS month_after 
    FROM numbers 
), policy_dates AS (
SELECT 
    PolicyNumber 
, CASE 
     WHEN month_of < PolicyEffectiveDate THEN PolicyEffectiveDate 
     ELSE month_of 
    END AS StartRiskMonth 
, CASE 
     WHEN PolicyExpirationDate < month_after THEN PolicyExpirationDate 
     WHEN Earned_to_date.Earned_to_date < month_after THEN Earned_to_date 
     ELSE month_after 
    END AS EndRiskMonth 
, DateDiff(day, PolicyEffectiveDate, PolicyExpirationDate) AS policy_days 
, WrittenPremium 
    FROM policy_data 
    JOIN calendar 
     ON (policy_data.PolicyEffectiveDate < calendar.month_after 
     AND calendar.month_of < policy_data.PolicyExpirationDate) 
    CROSS JOIN Earned_to_date 
    WHERE month_of < Earned_to_date 
) 
SELECT  
      Year(StartRiskMonth) as YearStartRisk, 
      Month(StartRiskMonth) as MonthStartRisk, 
      c.YearNum,c.MonthNum, 
      convert(varchar(7), StartRiskMonth, 120) as RiskMonth, 
      sum(WrittenPremium * DateDiff(day, StartRiskMonth, EndRiskMonth)/policy_days) as EarnedPremium 
FROM  tblCalendar c 
      LEFT JOIN policy_dates l ON c.YearNum=Year(l.StartRiskMonth) AND c.MonthNum = Month(l.StartRiskMonth) 
      AND l.StartRiskMonth BETWEEN '01-01-2015' AND '12-31-2016' 
WHERE  c.YearNum Not IN (2017) 
GROUP BY convert(varchar(7), StartRiskMonth, 120), 
      Year(StartRiskMonth) , Month(StartRiskMonth), 
      c.YearNum,c.MonthNum 
ORDER BY c.YearNum,c.MonthNum 

什么将是提高性能的最佳方式？ 10我在两张表上创建了non-clustered索引PolicyNumber。但仍然没有。 就像我说的，在我看来，如果SQL引擎会处理需要3秒的第一部分（PolicyNumber筛选），然后执行另外3秒的部分（计算这些PolicyNumber的部分） - 这太棒了。 但我是DBA的新手，所以我不确定它有可能。 有什么建议吗？ 感谢

执行计划::

最终结果：

Answer 1

你必须使你的代码更易读。通过临时表而不是cte将它分成更小的块。

你的麻烦：

HAVING COUNT (CASE WHEN ClassCode NOT IN (5151) THEN 1 END)=0 

如果ClassCode是5000在您具有含COUNT（TRUE - > 1）。

如果ClassCode在您有HAVING COUNT（FALSE - > NULL）时为5151。

应组之前进行过滤：

WHERE ClassCode IN (5151) -- and check index