Question

我正在尝试调查每个索引的页数，并制定了以下查询：

SELECT              
        pyi.index_type_desc as [index type],
        i.name as [index name],
        sum(pyi.page_count) as [number of pages]
FROM 
    sys.dm_db_index_physical_stats(DB_ID('testdb'),OBJECT_ID('surrogatekeys'),NULL,NULL,'DETAILED') as pyi
INNER JOIN 
    sys.indexes as i ON pyi.object_id = i.object_id     
GROUP BY 
    i.name, pyi.index_type_desc

当我运行此查询时，我得到以下结果：

CLUSTERED INDEX PK_TableWithSurrogateKeyAndUniqueContraints 14342
CLUSTERED INDEX UNIQUE_TableWithSurrogateKeyAndUniqueContraints 14342
NONCLUSTERED INDEX  PK_TableWithSurrogateKeyAndUniqueContraints 707
NONCLUSTERED INDEX  UNIQUE_TableWithSurrogateKeyAndUniqueContraints 707

此表创建如下：

CREATE TABLE [dbo].[SurrogateKeys]
(
    [Id] [int] IDENTITY(1,1) NOT NULL,
    [TimeStamp] [datetime2](7) NOT NULL,
    [Username] [nvarchar](20) NOT NULL, 
    [Message] [nvarchar](500) NULL,

    CONSTRAINT [PK_TableWithSurrogateKeyAndUniqueContraints] 
       PRIMARY KEY CLUSTERED ([Id]),
    CONSTRAINT [UNIQUE_TableWithSurrogateKeyAndUniqueContraints] 
       UNIQUE ([Username], [TimeStamp]),
) ON [PRIMARY]
GO

并填充100,000行随机数据。

我希望看到两个条目：唯一约束的非聚集索引和主键列的聚簇索引。

这些双重条目是什么意思？

Answer 1

这意味着您的JOIN条件错误了 - 您还需要在index_id条件中加入JOIN - 就像这样：

INNER JOIN 
    sys.indexes as i ON pyi.object_id = i.object_id 
                      AND pyi.index_id = i.index_id

SQL Server 2008：索引中的页数

1 个答案: