[英]Index on nvarchar datatype with XML data in SQL Server
I have a table with this structure : 我有一个具有这种结构的表:
CREATE TABLE [dbo].[GasTests]
(
[Id] [bigint] IDENTITY(1,1) NOT NULL,
[GasReceptionId] [bigint] NOT NULL,
[LineId] [bigint] NOT NULL,
[LabelCode] [nvarchar](max) NULL,
[StartTestDatetime] [datetime] NULL,
[EndTestDatetime] [datetime] NULL,
[ResultTest] [nvarchar](max) NULL,
CONSTRAINT [PK_dbo.GasTests]
PRIMARY KEY CLUSTERED ([Id] ASC)
)
In resulttest I store a xml datatype like this : 在resulttest中,我存储这样的xml数据类型:
<?xml version="1.0" encoding="utf-16"?>
<GasResultTestParameterView xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<ReceptionId>86</ReceptionId>
<ISIRI_9426_C1>on</ISIRI_9426_C1>
<ISIRI_9426_C2>on</ISIRI_9426_C2>
<ISIRI_9426_C3>on</ISIRI_9426_C3>
<ISIRI_9426_C4>on</ISIRI_9426_C4>
<ISIRI_9426_C5>on</ISIRI_9426_C5>
<ISIRI_9426_C6>on</ISIRI_9426_C6>
<ISIRI_9426_C7>on</ISIRI_9426_C7>
<ISIRI_9426_C8>on</ISIRI_9426_C8>
<ISIRI_9426_C9>on</ISIRI_9426_C9>
<ISIRI_9426_C10>on</ISIRI_9426_C10>
<ISIRI_9426_C11>on</ISIRI_9426_C11>
<ISIRI_9426_C12>on</ISIRI_9426_C12>
<ISIRI_9426_C13>on</ISIRI_9426_C13>
<ISIRI_9426_C14>on</ISIRI_9426_C14>
<ISIRI_9426_C15>on</ISIRI_9426_C15>
<ISIRI_9426_C16>on</ISIRI_9426_C16>
<ISIRI_9426_C17>on</ISIRI_9426_C17>
<ISIRI_9426_C18>on</ISIRI_9426_C18>
<ISIRI_9426_C19>on</ISIRI_9426_C19>
<ISIRI_9426_C20>on</ISIRI_9426_C20>
<ISIRI_9426_C21>on</ISIRI_9426_C21>
<ISIRI_9426_C22>on</ISIRI_9426_C22>
<ISIRI_9426_C23>on</ISIRI_9426_C23>
<ISIRI_9426_C24>on</ISIRI_9426_C24>
<ISIRI_9426_C25>on</ISIRI_9426_C25>
<ISIRI_9426_C26>on</ISIRI_9426_C26>
<ISIRI_9426_C27>on</ISIRI_9426_C27>
<ISIRI_9426_C28>on</ISIRI_9426_C28>
<ISIRI_9426_C29>on</ISIRI_9426_C29>
<ISIRI_9426_C30>on</ISIRI_9426_C30>
<ISIRI_9747_K1>on</ISIRI_9747_K1>
<ISIRI_9747_K2>on</ISIRI_9747_K2>
<ISIRI_9747_K3>on</ISIRI_9747_K3>
<ISIRI_9747_K4>on</ISIRI_9747_K4>
<ISIRI_9747_K5>on</ISIRI_9747_K5>
<ISIRI_9747_K6>on</ISIRI_9747_K6>
<ISIRI_9747_K7>on</ISIRI_9747_K7>
<ISIRI_9747_K8>on</ISIRI_9747_K8>
<ISIRI_9747_K9>on</ISIRI_9747_K9>
<ISIRI_9747_K10>on</ISIRI_9747_K10>
<ISIRI_9747_K11>on</ISIRI_9747_K11>
<ISIRI_9747_K12>on</ISIRI_9747_K12>
<ISIRI_9747_K13>on</ISIRI_9747_K13>
<ISIRI_9747_K14>on</ISIRI_9747_K14>
<ISIRI_9747_K15>on</ISIRI_9747_K15>
<ISIRI_9747_K16>on</ISIRI_9747_K16>
<ISIRI_9747_K17>on</ISIRI_9747_K17>
<ISIRI_9747_K18>on</ISIRI_9747_K18>
<ISIRI_9747_K19>on</ISIRI_9747_K19>
<ISIRI_9747_K20>on</ISIRI_9747_K20>
<ISIRI_9747_K21>on</ISIRI_9747_K21>
<ISIRI_9747_K22>on</ISIRI_9747_K22>
<ISIRI_9747_K23>on</ISIRI_9747_K23>
<ISIRI_9747_K24>on</ISIRI_9747_K24>
<ISIRI_9747_K25>on</ISIRI_9747_K25>
<ISIRI_9747_K26>on</ISIRI_9747_K26>
<ISIRI_9747_K27>on</ISIRI_9747_K27>
<ISIRI_9747_K28>on</ISIRI_9747_K28>
<ISIRI_9747_K29>on</ISIRI_9747_K29>
<ISIRI_9747_K30>on</ISIRI_9747_K30>
<ISIRI_9747_K31>on</ISIRI_9747_K31>
<ISIRI_9747_K32>on</ISIRI_9747_K32>
<ISIRI_9747_K33>on</ISIRI_9747_K33>
<ISIRI_9747_K34>on</ISIRI_9747_K34>
<ISIRI_9747_K35>on</ISIRI_9747_K35>
<ISIRI_9747_K36>on</ISIRI_9747_K36>
<ISIRI_9747_K37>on</ISIRI_9747_K37>
<ISIRI_9747_K38>on</ISIRI_9747_K38>
<ISIRI_9747_K39>on</ISIRI_9747_K39>
<ISIRI_9747_K40>on</ISIRI_9747_K40>
<ISIRI_9747_K41>on</ISIRI_9747_K41>
<ISIRI_9747_K42>on</ISIRI_9747_K42>
<ISIRI_9747_K43>on</ISIRI_9747_K43>
<ISIRI_9747_K44>on</ISIRI_9747_K44>
<ISIRI_9747_K45>on</ISIRI_9747_K45>
<ISIRI_9747_K46>on</ISIRI_9747_K46>
<TapCompany>LANDIRENZO</TapCompany>
<TapSerialNumber>039837</TapSerialNumber>
<RegulatorCompany>OMVL</RegulatorCompany>
<RegulatorSerialNumber>039837</RegulatorSerialNumber>
<CapsuleCompany>JINDUN</CapsuleCompany>
<CapsuleSerialNumber>1004986</CapsuleSerialNumber>
<CapsuleType>2</CapsuleType>
<CapsuleBuiltDate>1391</CapsuleBuiltDate>
<CapsuleExpireDate>1402</CapsuleExpireDate>
<GasSystemGeneration>2</GasSystemGeneration>
<Remark>تایید</Remark>
<PassedISIRI9747>on</PassedISIRI9747>
<PassedISIRI9426>on</PassedISIRI9426>
<PassedISIRI6792>noneed</PassedISIRI6792>
</GasResultTestParameterView>
I need a lot of reports based on my xml result. 我需要大量基于xml结果的报告。 But when I want to search an item in my XML, it takes a lot of time.
但是,当我想在XML中搜索项目时,会花费很多时间。 How can I make my table and my xml faster?
如何使表和xml更快?
If you define your Resulttest
column as XML
, then you can fetch individual bits from your XML and store them into your table structure - as computed columns . 如果将
Resulttest
列定义为XML
,则可以从XML中获取各个位并将其存储为表列 (作为计算列) 。
Storing as XML has two main benefits: 以XML格式存储有两个主要好处:
XML
column allows you to use the XQuery function on it, to handle the XML structures XML
列可让您在其上使用XQuery函数来处理XML结构 First, define a scalar function like this (assuming you want to "surface" the TapCompany
value): 首先,定义一个这样的标量函数(假设您想“
TapCompany
” TapCompany
值):
CREATE FUNCTION dbo.GetTapCompany(@Input XML)
RETURNS VARCHAR(100)
AS
BEGIN
DECLARE @Result VARCHAR(100)
SELECT @Result = @Input.value('(/GasResultTestParameterView/TapCompany)[1]', 'VARCHAR(100)')
RETURN @Result
END
This function takes the XML value (from your table row) as input, goes into the XML and gets the TapCompany
value, and returns it. 此函数将XML值(来自表行)作为输入,进入XML并获取
TapCompany
值,然后将其返回。
Then, add this as a column to your database table: 然后,将其作为列添加到数据库表中:
ALTER TABLE dbo.GasTests
ADD TapCompany AS dbo.GetTapCompany(Resulttest);
Now, you should be able to select from your table, and get the value of TapCompany
along side your other table values: 现在,您应该能够从表中进行选择,并获得
TapCompany
的值以及其他表的值:
SELECT
Id,
GasReceptionId,
LineId,
LabelCode,
TapCompany
FROM
dbo.GasTests
Unfortunately, you cannot make this column persisted - so each time you select from that table and include that column, the scalar function that provides the value will be called. 不幸的是,您不能使该列持久存在 -因此,每次从该表中选择并包括该列时,都会调用提供该值的标量函数。 Therefore, I'm unsure if you'll see any performance improvement - but I think that should be quite easy to check for you - with your real data - give it a try!
因此,我不确定您是否会看到任何性能改进-但我认为应该很容易检查一下-使用您的真实数据-试试看!
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