I have a process which process the history data. I want to know if I use exists function in the where it will improve any performance..

declare @data xml
set @data  ='<AuditData><Data><Inserted><ins>
    <Endocrine><Endocrine Asymptomatic="0" Lethargy="0" >
      <Diabetic value="1" DietControlled="0" OralMedication="0">
    	<Insulin value="0" />
      </Diabetic>
      <DisposalSharps value="1" />
      <Comments value="" />
    </Endocrine></Endocrine></ins></Inserted></Data></AuditData>'

select pref.query('Endocrine') as value
FROM  @data.nodes('//AuditData/Data/Inserted/ins/Endocrine') AS d(pref)

select pref.query('Endocrine') as value
FROM  @data.nodes('//AuditData/Data/Inserted/ins/Endocrine') AS d(pref)
WHERE @data.exist('(//Endocrine)') = 1

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