从 SQL 服务器读取 XML 数据会降低性能

Question

我正在 SQL 查看以下脚本。由于 table 将数据存储为 XML (dbo.TEST.configuration)，我必须通过读取 xml 数据来 select 每列。但是当记录增加时，加载速度变得太慢了。有什么方法可以提高它的性能，请告诉我？

WITH XMLNAMESPACES( DEFAULT 'http://tempuri.org/xmlConfiguration.xsd')

SELECT      dbo.TEST.uid, dbo.TEST.name, dbo.TEST.ClassUid, dbo.TEST.xmlData, 
                  CAST(REPLACE(CAST(dbo.TEST.configuration AS VARCHAR(MAX)), 'encoding="utf-8"', '') 
                  AS XML ).value('(/xmlConfiguration/batchUid)[1]', 'NVARCHAR(200)') AS batchUid, 
                  CAST(REPLACE(CAST(dbo.TEST.xmlData AS VARCHAR(MAX)), 'encoding="utf-8"', '') 
                  AS XML ).value('(/xmlConfiguration/statusUid)[1]', 'NVARCHAR(200)') AS statusUid, 
                  CAST(REPLACE(CAST(dbo.TEST.xmlData AS VARCHAR(MAX)), 'encoding="utf-8"', '') 
                  AS XML ).value('(/xmlConfiguration/subjectUid)[1]', 'NVARCHAR(200)') AS subjectUid, 
                  CAST(REPLACE(CAST(dbo.TEST.xmlData AS VARCHAR(MAX)), 'encoding="utf-8"', '') 
                  AS XML ).value('(/xmlConfiguration/cultureUid)[1]', 'NVARCHAR(200)') AS cultureUid, 
                  CAST(REPLACE(CAST(dbo.TEST.xmlData AS VARCHAR(MAX)), 'encoding="utf-8"', '') 
                  AS XML ).value('(/xmlConfiguration/format)[1]', 'NVARCHAR(200)') AS format, 
                  CAST(REPLACE(CAST(dbo.TEST.xmlData AS VARCHAR(MAX)), 'encoding="utf-8"', '') 
                  AS XML ).value('(/xmlConfiguration/secondFormat)[1]', 'NVARCHAR(200)') AS secondFormat, 
                  CAST(REPLACE(CAST(dbo.TEST.xmlData AS VARCHAR(MAX)), 'encoding="utf-8"', '') 
                  AS XML ).value('(/xmlConfiguration/standardUid)[1]', 'NVARCHAR(200)') AS standardUid
FROM         dbo.TEST INNER JOIN
                  dbo.batch ON CAST(REPLACE(CAST(dbo.TEST.xmlData AS VARCHAR(MAX)), 'encoding="utf-8"', '') 
                  AS XML ).value('(/xmlConfiguration/batchUid)[1]', 'NVARCHAR(200)') = dbo.batch.uid INNER JOIN
                  dbo.status ON CAST(REPLACE(CAST(dbo.TEST.xmlData AS VARCHAR(MAX)), 'encoding="utf-8"', '') 
                  AS XML ).value('(/xmlConfiguration/statusUid)[1]', 'NVARCHAR(200)') = dbo.status.uid INNER JOIN
                  dbo.vFormat ON CAST(REPLACE(CAST(dbo.TEST.xmlData AS VARCHAR(MAX)), 'encoding="utf-8"', '') 
                  AS XML ).value('(/xmlConfiguration/format)[1]', 'NVARCHAR(200)') = CONVERT(NVARCHAR(200), dbo.vFormat.uid) OR
                  CAST(REPLACE(CAST(dbo.TEST.xmlData AS VARCHAR(MAX)), 'encoding="utf-8"', '') 
                  AS XML ).value('(/xmlConfiguration/secondFormat)[1]', 'NVARCHAR(200)') = CONVERT(NVARCHAR(200), dbo.vFormat.uid) INNER JOIN
                  dbo.standard ON CAST(REPLACE(CAST(dbo.TEST.xmlData AS VARCHAR(MAX)), 'encoding="utf-8"', '') 
                  AS XML ).value('(/xmlConfiguration/standardUid)[1]', 'NVARCHAR(200)') = dbo.standard.uid INNER JOIN
                  mainDb.dbo.Class ON dbo.TEST.ClassUid = mainDb.dbo.Class.uid INNER JOIN
                  dbo.subject ON CAST(REPLACE(CAST(dbo.TEST.xmlData AS VARCHAR(MAX)), 'encoding="utf-8"', '') 
                  AS XML ).value('(/xmlConfiguration/subjectUid)[1]', 'NVARCHAR(200)') = dbo.subject.uid INNER JOIN
                  mainDb.dbo.culture ON CAST(REPLACE(CAST(dbo.TEST.xmlData AS VARCHAR(MAX)), 'encoding="utf-8"', '') 
                  AS XML ).value('(/xmlConfiguration/cultureUid)[1]', 'NVARCHAR(200)') = mainDb.dbo.culture.uid

提前致谢。

样本xml数据如下；

 <?xml version="1.0" encoding="utf-8"?> 
 <xmlConfiguration xmlns="http://tempuri.org/xmlConfiguration.xsd">              
 <secondFormat>3bd3d9cc-ad0a-e611-b086-00e04c6804ad</secondFormat>               
 <batchUid>c7b4743b-4493-df11-981e-00221933d118</batchUid>               
 <statusUid>f0b159ec-4193-df11-981e-00221933d118</statusUid>               
 <subjectUid>d07b5d66-3b5b-de11-b569-001143e78e41</subjectUid>               
 <cultureUid>c6644752-93d7-df11-981e-00221933d118</cultureUid>               
 <name>test</name>               
 <standardUid>dc19869b-3ea9-df11-981e-00221933d118</standardUid>               
 <format></format>            
</ConnectorConfiguration>

Answer 1

;WITH XMLNAMESPACES( DEFAULT 'http://tempuri.org/xmlConfiguration.xsd')
SELECT
    x.uid,
    x.name,
    x.ClassUid,
    x.xmlData, 
    x.batchUid, 
    x.statusUid, 
    x.subjectUid, 
    x.cultureUid, 
    x.format, 
    x.secondFormat, 
    x.standardUid
FROM (
    SELECT *,
        x.value('(/xmlConfiguration/batchUid)[1]', 'NVARCHAR(200)') AS batchUid, 
        x.value('(/xmlConfiguration/statusUid)[1]', 'NVARCHAR(200)') AS statusUid, 
        x.value('(/xmlConfiguration/subjectUid)[1]', 'NVARCHAR(200)') AS subjectUid, 
        x.value('(/xmlConfiguration/cultureUid)[1]', 'NVARCHAR(200)') AS cultureUid, 
        x.value('(/xmlConfiguration/format)[1]', 'NVARCHAR(200)') AS format, 
        x.value('(/xmlConfiguration/secondFormat)[1]', 'NVARCHAR(200)') AS secondFormat, 
        x.value('(/xmlConfiguration/standardUid)[1]', 'NVARCHAR(200)') AS standardUid
    FROM (
        SELECT *, x = CAST(
                CAST(REPLACE(CAST(xmlData AS VARCHAR(MAX)), 'encoding="utf-8"', '') AS XML
            ).query('.') ---- .query('.')
        FROM dbo.TEST
    ) T
) x
JOIN dbo.batch ON x.batchUid = dbo.batch.uid
JOIN dbo.status ON x.statusUid = dbo.status.uid
JOIN dbo.vFormat ON CONVERT(NVARCHAR(200), dbo.vFormat.uid) IN (x.format, x.secondFormat)
JOIN dbo.standard ON x.standardUid = dbo.standard.uid
JOIN mainDb.dbo.Class ON dbo.TEST.ClassUid = mainDb.dbo.Class.uid
JOIN dbo.subject ON x.subjectUid = dbo.subject.uid
JOIN mainDb.dbo.culture ON x.cultureUid = mainDb.dbo.culture.uid

从 SQL 服务器读取 XML 数据会降低性能

Reading from XML data from SQL Server reduces performance

sql

sql-server

performance

sql-server-2008

sql-tuning