索引视图可用性

Question

我有一个索引视图：

CREATE VIEW ptv.vw_mokiniai_2
 WITH SCHEMABINDING
 AS 
  SELECT 
    T1.year_name,
    T2.person_id,
    T2.year,
    T2.person_position,
    COUNT_BIG(*) AS [aggregated number]
  FROM Table1 AS T1 
  INNER JOIN Table2 AS T2
     ON T1.year = T2.year
  GROUP BY T1.year_name,
    T2.person_id,
    T2.year,
    T2.person_position

在列上具有唯一的聚集索引

T1.year_name, T2.person_id, T2.year, T2.person_position

我需要查询优化器在查询中使用这个索引视图

SELECT 
    T1.year_name, 
    COUNT_BIG(DISTINCT T3.person_id) AS [persons_per_year]
FROM Table1 AS T1
INNER JOIN (
            SELECT 
              T2.person_id,
              T2.year,
              T2.person_position
            FROM Table2 AS T2 
            GROUP BY T2.person_id, T2.year, T2.person_position
            ) AS T3 
    ON T1.year = T3.year
GROUP BY T1.year_name

查询必须使用派生表，因为 COGNOS 会生成此查询，而我不想编辑多维模型。有人知道怎么做吗？也许优化查询的唯一方法是删除派生表（意味着我必须编辑多维模型）？任何建议（查看编辑和最终查询编辑）将不胜感激。

Answer 1

下面的示例在我的测试中使用了索引视图。如果这在您的环境中不起作用，则您发布的代码中可能存在不明显的差异。

CREATE TABLE dbo.Table1
    (
      year varchar(10)
    , year_name varchar(10)
    );

CREATE TABLE dbo.Table2
    (
      year varchar(10)
    , person_id varchar(10)
    , person_position varchar(10)
    );
GO

CREATE VIEW dbo.vw_mokiniai_2
WITH SCHEMABINDING
AS
    SELECT  T2.person_id
          , T2.year
          , T2.person_position
          , COUNT_BIG(*) AS [aggregated number]
    FROM    dbo.Table2 AS T2
    GROUP BY T2.person_id
          , T2.year
          , T2.person_position
GO
CREATE UNIQUE CLUSTERED INDEX cdx ON vw_mokiniai_2(year, person_id, person_position)
GO

SELECT 
    T1.year_name, 
    COUNT_BIG(DISTINCT T3.person_id) AS [persons_per_year]
FROM Table1 AS T1
INNER JOIN (
            SELECT 
              T2.person_id,
              T2.year,
              T2.person_position
            FROM Table2 AS T2 
            GROUP BY T2.person_id, T2.year, T2.person_position
            ) AS T3 
    ON T1.year = T3.year
GROUP BY T1.year_name
GO