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SQL Server 2008 中使用 XML.Modify() 进行查询的性能优化

[英]Performance Optimization of query using XML.Modify() in SQL Server 2008

 原文  2016-04-18 17:49:32  6   1    sql/ sql-server/ xml/ performance/ sql-server-2008

问题描述

我在 SQL Server 2008 中使用 FOR XML 生成 XML。

生成的 XML 输出为 5.18 MB，生成 XML 的过程仅需 5 秒。

现在，我使用 XML.modify 在这个 XML 中添加属性。 修改后大小增加到 5.25 MB。 但是该文件需要 17 分钟进行剩余的处理（添加属性）。

我将 XML 数据保存在一个 XML 类型变量中，这个 XML 文档中大约有 6000 行，我在大约一半的行中添加了属性。 这些属性是在不同的节点下添加的，具有一定的条件。 添加这些属性时会消耗大约 17 分钟（约 16 分钟）的最长时间。

如果有人可以告诉我提高性能的最佳实践和方法，我会请求。

添加样式之前生成的 XML

        <?xml version="1.0"?>
        <?mso-application progid="Excel.Sheet"?>
        <Workbook xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet" xmlns="urn:schemas-microsoft-com:office:spreadsheet">
          <Worksheet xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet" xmlns="urn:schemas-microsoft-com:office:spreadsheet" ss:Name="INDEX">
            <Table xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet" xmlns="urn:schemas-microsoft-com:office:spreadsheet">
              <Column></Column>
              <Row xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet" xmlns="urn:schemas-microsoft-com:office:spreadsheet">
                <Cell xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet" xmlns="urn:schemas-microsoft-com:office:spreadsheet">
                  <Data ss:Type="String">#</Data>
                </Cell>
                <Cell xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet" xmlns="urn:schemas-microsoft-com:office:spreadsheet">
                  <Data ss:Type="String">Study Name</Data>
                </Cell>

添加属性后的 XML

        <?xml version="1.0"?>
        <?mso-application progid="Excel.Sheet"?>
        <Workbook xmlns="urn:schemas-microsoft-com:office:spreadsheet" xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet">
          <Styles xmlns="urn:schemas-microsoft-com:office:spreadsheet" xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet">

          <Worksheet xmlns="urn:schemas-microsoft-com:office:spreadsheet" xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet" ss:Name="INDEX">
            <Table xmlns="urn:schemas-microsoft-com:office:spreadsheet" xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet" ss:DefaultRowHeight="50">
              <Row xmlns="urn:schemas-microsoft-com:office:spreadsheet" xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet" ss:StyleID="s66">
                <Cell xmlns="urn:schemas-microsoft-com:office:spreadsheet" xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet" ss:MergeAcross="5">
                  <Data ss:Type="String">#</Data>
                </Cell>
                <Cell xmlns="urn:schemas-microsoft-com:office:spreadsheet" xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet">
                  <Data ss:Type="String">Study Name</Data>
                </Cell>

生成基本 XML 的代码

CREATE TABLE TempData (
    [ID] [INT] NOT NULL IDENTITY(1, 1) PRIMARY KEY
    ,[Col1] [NVARCHAR](MAX)
    ,[Col2] [NVARCHAR](MAX)
    ,[Col3] [NVARCHAR](MAX)
    ,[WORKSHEET_ID] INT 
    ,[FORM_OID] [NVARCHAR](MAX)
    ,[Col4] [NVARCHAR](MAX)
    ,[Col5] [NVARCHAR](MAX)
    ,[Col6] [NVARCHAR](MAX)
    ,[Col7] [NVARCHAR](MAX)
    ,[Col8] [NVARCHAR](MAX)
    ,[Col9] [NVARCHAR](MAX)
    ,[RANKING] INT
    );

SELECT  @xml = (SELECT (
          SELECT  
            CASE WHEN a2.[FORM_OID]='INDEX' THEN a2.[FORM_OID]
            ELSE  SUBSTRING(CONVERT(varchar(10),(a2.[WORKSHEET_ID]-1))+'_'+ a2.[FORM_OID],0,31) 
            END  '@ss:Name',(
                  SELECT '' as [Column],(
                           SELECT   
                               (SELECT 
                                      'String' as [Data/@ss:Type],
                                      [Col1] as [Data]
                                      FOR XML PATH('Cell'), TYPE),
                                      (SELECT 
                                     'String' as [Data/@ss:Type],
                                      [Col2] as [Data]  
                                      FOR XML PATH('Cell'), TYPE),
                                      (SELECT 
                                     'String' as [Data/@ss:Type],
                                      [Col3] as [Data]  
                                      FOR XML PATH('Cell'), TYPE),
                                      (SELECT 
                                     'String' as [Data/@ss:Type],
                                      [Col4] as [Data]  
                                      FOR XML PATH('Cell'), TYPE),
                                      (SELECT 
                                     'String' as [Data/@ss:Type],
                                      [Col5] as [Data]  
                                      FOR XML PATH('Cell'), TYPE),
                                      (SELECT 
                                     'String' as [Data/@ss:Type],
                                      [Col6] as [Data]  
                                      FOR XML PATH('Cell'), TYPE),
                                      (SELECT 
                                     'String' as [Data/@ss:Type],
                                      [Col7] as [Data]  
                                      FOR XML PATH('Cell'), TYPE),
                                      (SELECT 
                                     'String' as [Data/@ss:Type],
                                      [Col8] as [Data]  
                                      FOR XML PATH('Cell'), TYPE),
                                      (SELECT 
                                     'String' as [Data/@ss:Type],
                                      [Col9] as [Data]  
                                      FOR XML PATH('Cell'), TYPE),
                                      (SELECT 
                                     'String' as [Data/@ss:Type],
                                      [RANKING] as [Data]  
                                      FOR XML PATH('Cell'), TYPE)
                               FROM TempData  a1
                               WHERE a1.[WORKSHEET_ID]=a2.[WORKSHEET_ID]
                               GROUP BY [ID],[Col1],[Col2],[Col3],[FORM_OID],[Col4],[Col5],[Col6],[Col7],[Col8],[Col9],[RANKING] --form oid
                               order by [ID]
                         FOR XML PATH('Row'), TYPE
                         )
                  FOR XML PATH('Table'), TYPE
                         )
           FROM TempData  a2
           group by [WORKSHEET_ID],[FORM_OID]
    FOR XML PATH('Worksheet'), TYPE)          
    FOR XML PATH('Workbook'), TYPE )

添加样式的代码（我添加的众多属性之一）

SET @xml.modify('declare default element namespace  "urn:schemas-microsoft-com:office:spreadsheet";
                    declare namespace ss="urn:schemas-microsoft-com:office:spreadsheet" ;
                    declare namespace x="urn:schemas-microsoft-com:office:excel";
                    insert  attribute ss:MergeAcross{"5"}           
                    into (/Workbook/Worksheet[position()=sql:variable("@worksheets")][1]/Table/Row[1]/Cell[1])[1]')

1 个解决方案

解决方案1
 1 已采纳  2016-04-18 20:47:33

通过避免如此多的重复命名空间声明，这个修改后的查询至少会大大减少字节数。 如果你不能接受我的建议（阅读下文），无论如何这应该会加快速度。 3000 次 RBAR 修改调用应该会更快，大约 10% 的大小......

我希望您可以将其用于完整查询：

CREATE TABLE TempData (
    [ID] [INT] NOT NULL IDENTITY(1, 1) PRIMARY KEY
    ,[Col1] [NVARCHAR](MAX)
    ,[Col2] [NVARCHAR](MAX)
    ,[Col3] [NVARCHAR](MAX)
    ,[WORKSHEET_ID] INT 
    ,[FORM_OID] [NVARCHAR](MAX)
    ,[Col4] [NVARCHAR](MAX)
    ,[Col5] [NVARCHAR](MAX)
    ,[Col6] [NVARCHAR](MAX)
    ,[Col7] [NVARCHAR](MAX)
    ,[Col8] [NVARCHAR](MAX)
    ,[Col9] [NVARCHAR](MAX)
    ,[RANKING] INT
    );
INSERT INTO TempData(Col1,Col2,Col3,WORKSHEET_ID,FORM_OID,Col4,Col5,Col6,Col7,Col8,Col9,RANKING) 
VALUES('test1','test2','test3',1,'formOID','test4','test5','test6','test7','test8','test9',100);

DECLARE @xml XML;
WITH XMLNAMESPACES('urn:schemas-microsoft-com:office:spreadsheet' AS ss
                  ,'urn:schemas-microsoft-com:office:excel' AS x
                  ,DEFAULT 'urn:schemas-microsoft-com:office:spreadsheet')
SELECT  @xml = 
(
    SELECT  
        CASE WHEN a2.[FORM_OID]='INDEX' THEN a2.[FORM_OID]
        ELSE  SUBSTRING(CONVERT(varchar(10),(a2.[WORKSHEET_ID]-1))+'_'+ a2.[FORM_OID],0,31) 
        END  '@ss:Name',
        (
            SELECT '' as [Column],
            (
                SELECT   
                    'String' as [Cell/Data/@ss:Type],
                    [Col1] as [Cell/Data],
                    '',
                    'String' as [Cell/Data/@ss:Type],
                    [Col2] as [Cell/Data],
                    '',
                    'String' as [Cell/Data/@ss:Type],
                    [Col3] as [Cell/Data],
                    '',
                    5 AS [Cell/@ss:MergeAcross],       --Read below!
                    'String' as [Cell/Data/@ss:Type],
                    [Col4] as [Cell/Data],
                    '',
                    'String' as [Cell/Data/@ss:Type],
                    [Col5] as [Cell/Data],
                    '',
                    'String' as [Cell/Data/@ss:Type],
                    [Col7] as [Cell/Data],
                    '',
                    'String' as [Cell/Data/@ss:Type],
                    [Col8] as [Cell/Data],
                    '',
                    'String' as [Cell/Data/@ss:Type],
                    [Col9] as [Cell/Data],
                    '',
                    'String' as [Cell/Data/@ss:Type],
                    [RANKING] as [Cell/Data]

                    FROM TempData  a1
                    WHERE a1.[WORKSHEET_ID]=a2.[WORKSHEET_ID]
                    GROUP BY [ID],[Col1],[Col2],[Col3],[FORM_OID],[Col4],[Col5],[Col6],[Col7],[Col8],[Col9],[RANKING] --form oid
                    order by [ID]
                FOR XML PATH('Row'), TYPE
            ) 
            FOR XML PATH('Table'), TYPE
        )
    FROM TempData  a2
    group by [WORKSHEET_ID],[FORM_OID]
    FOR XML PATH('Worksheet'), ROOT('Workbook')
);

SELECT @xml;

--CleanUp
--DROP TABLE TempData;

如果您仔细观察“Col4”，您会发现我在调用中直接引入了 MergeAcross-Attribut。 如果样式是 1:n 并“即时”添加它们，您如何看待向临时表添加更多列或为样式定义第二个临时表？

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