通过预过滤结果加速 SQL 视图答案

【问题标题】：Speeding up a SQL view by pre-filtering results通过预过滤结果加速 SQL 视图
【发布时间】：2019-03-01 11:41:04
【问题描述】：

我有一个在一张非常大的桌子上运行的视图。

CREATE VIEW [myView]
AS

-- first part
WITH A AS (
SELECT MAX(Id), ResultId, LocationId, TeamId
FROM VeryLargeTable
GROUP BY ResultId, LocationId, TeamId)    
--second part
SELECT A.Id, A.TeamId, ROW_NUMBER() OVER (PARTITION BY ResultId, LocationId) RN  
FROM A
WHERE RN = 1
GO

现在我运行诸如

之类的操作

SELECT * from [MyView] 
WHERE TeamId = 5

这很慢，因为它本质上是在执行

WITH A AS (
SELECT MAX(Id), ResultId, LocationId, TeamId
FROM VeryLargeTable
GROUP BY ResultId, LocationId, TeamId)    
--second part
SELECT A.Id, A.TeamId, ROW_NUMBER() OVER (PARTITION BY ResultId, LocationId) RN  
FROM A
WHERE RN = 1 AND TeamId = 5

我想知道的是如何构建这个视图，以便它知道在第一部分过滤TeamId = 5，以便执行以下快速的代码

WITH A AS (
SELECT MAX(Id), ResultId, LocationId, TeamId
FROM VeryLargeTable
GROUP BY ResultId, LocationId, TeamId
WHERE TeamId = 5)    
--second part
SELECT A.Id, A.TeamId, ROW_NUMBER() OVER (PARTITION BY ResultId, LocationId) RN  
FROM A
WHERE RN = 1

【问题讨论】：

请发布您的实际代码。视图不能包含临时表。第二 - 谓词下推应该工作
嗯，好的，我目前正在使用 CTE 进行此操作 - 将转换
VeryLargeTable 上有哪些索引？当您有几分钟的空闲时间时，请阅读“XY 问题”:)
@Lukasz 可以是列的任意组合

标签： sql-server tsql query-optimization sql-server-2016 sql-view

【解决方案1】：

您可以将视图重写为内联 TVF：

CREATE FUNCTION dbo.my_func(@TeamId INT)
RETURNS TABLE
AS
RETURN
(
WITH A AS (
  SELECT MAX(Id), ResultId, LocationId, TeamId
  FROM VeryLargeTable
  WHERE TeamId = @TeamId OR @TeamId IS NULL
  GROUP BY ResultId, LocationId, TeamId
)    
--second part
SELECT A.Id, A.TeamId, ROW_NUMBER() OVER (PARTITION BY ResultId, LocationId) RN  
FROM A
WHERE RN = 1 
);

并查询：

SELECT *
FROM dbo.my_fun(5)
WHERE ...

【讨论】：