加快 SQL Server 2005 中的 XML 查询速度

Question

我将所有数据存储在 SQL Server 2005 的 XML 列中。

随着越来越多的记录被插入，我注意到查询速度正在减慢。我尝试创建主 XML 索引和辅助 VALUE 索引，但这对速度没有任何帮助。

我缺少任何提示、想法或技巧吗？

我查询的示例视图：

SELECT Id
, CaseNumber
, XmlTest.value('(/CodeFiveReport/ReportEvent/StartDate)[1]', 'varchar(25)') + ' ' + XmlTest.value('(/CodeFiveReport/ReportEvent/StartTime)[1]', 'varchar(25)') as StartDate
, XmlTest.value('(/CodeFiveReport/@Status)[1]', 'varchar(10)') as [Status]
, XmlTest.value('(/CodeFiveReport/ReportEvent/Address/PatrolDistrict/@Name)[1]', 'varchar(100)') as PatrolDistrict
, XmlTest.value('(/CodeFiveReport/PrimaryUnit/@Name)[1]', 'varchar(40)') as PrimaryUnit
, XmlTest.value('(/CodeFiveReport/ReportEvent/Address/@StreetNumber)[1]', 'varchar(50)') + ' ' + XmlTest.value('(/CodeFiveReport/ReportEvent/Address/@StreetName)[1]', 'varchar(50)') + ' ' + XmlTest.value('(/CodeFiveReport/ReportEvent/Address/StreetSuffix/@Name)[1]', 'varchar(50)') + ' ' + XmlTest.value('(/CodeFiveReport/ReportEvent/Address/@City)[1]', 'varchar(50)') + ' ' + XmlTest.value('(/CodeFiveReport/ReportEvent/Address/State/@Abbreviation)[1]', 'varchar(50)') + ' '  + XmlTest.value('(/CodeFiveReport/ReportEvent/Address/@ZipCode)[1]', 'varchar(50)') as Location
, XmlTest.value('(/CodeFiveReport/ReportEvent/ReportType/@Name)[1]', 'varchar(50)') as ReportType
, XmlTest.value('(/CodeFiveReport/ReportEvent/Offenses/OffenseDescription/OffenseType/@CodeAndDescription)[1]', 'varchar(50)') as IncidentType
, XmlTest as Report
, CreatedBy as UserId
, XmlTest.value('(/CodeFiveReport/PrimaryUnit/@ID)[1]', 'integer') as UnitId
, XmlTest.value('(/CodeFiveReport/PrimaryUnit/@Code)[1]', 'varchar(6)') as UnitCode
, XmlTest.value('(/CodeFiveReport/Owner/AgencyID)[1]', 'char(2)') as AgencyId   
, IsLocked
, LockedBy
, XmlTest.value('(/CodeFiveReport/VersionUsed)[1]', 'varchar(20)') as VersionUsed
FROM UploadReport
WHERE XmlTest.value('(/CodeFiveReport/Owner/AgencyID)[1]', 'char(2)') = '06'

Answer 1

仅当结果用于插入表或联接时，查询才会出现性能问题。只需从管理工作室中的选择返回值几乎是即时的。加上前缀，INSERT INTO完成同样的工作将需要 30 秒以上。

添加后/text()如

from @list.nodes('/List/Id/text()') as C(C)

而不是我所拥有的：

from @list.nodes('/List/Id') as C(C)

即使有插入，这也会使查询恢复到零秒执行。