SCOM SQL query killing instance performance

Question

Hi!
Since a few day, a new query running against our SCOM datawarehouse db is killing the performance of the SQL instance. The query run 1'000'000 times per hour for a total of 100'000'000 logical read per hour, and this continuously. The query is part of the
following Procedure: OperationsManagerDW.dbo.fn_BuildInstancePropertyDelta
Any idea what's wrong ?
What could trigger this new behavior ? 
Rgds
/Chris
Waiting on statement:
RETURN
   SELECT 1 AS Tag ,
      NULL AS Parent ,
      ISNULL(S1.PropertyGuid, S2.PropertyGuid) AS [Property!1!Guid] ,
      S1.PropertyValue AS [Property!1!NewValue!ELEMENT] ,
      S2.PropertyValue AS [Property!1!OldValue!ELEMENT]
   FROM
      SELECT PropertyGuid = Set1.PropertyXml.value('@Guid' ,'nvarchar(256)') ,
         PropertyValue = Set1.PropertyXml.value('.' ,'nvarchar(max)')
      FROM @PropertyXml1.nodes('Root/Property') AS Set1(PropertyXml)
      ) AS S1
   FULL JOIN
      SELECT PropertyGuid = Set1.PropertyXml.value('@Guid' ,'nvarchar(256)') ,
         PropertyValue = Set1.PropertyXml.value('.' ,'nvarchar(max)')
      FROM @PropertyXml2.nodes('Root/Property') AS Set1(PropertyXml)
      ) AS S2
   ON (S1.PropertyGuid = S2.PropertyGuid)
   WHERE (S1.PropertyValue <> S2.PropertyValue)
   OR ( (ISNULL(S1.PropertyValue, S2.PropertyValue) IS NOT NULL)
  AND ((S1.PropertyValue IS NULL)
   OR (S2.PropertyValue IS NULL)) ) FOR XML EXPLICIT

Answer 1

Hallo,
We open a ticket to Microsoft Support.
In the SCOM application logs, this huge SQL cpu activity correlates with an error 31553, Violation of unique key constraint.
We get the information that if the following query return some rows, it means you are hitting the same issue and you should better open a ticket to get information how to fix the problem.
select
* from ManagedEntityStage mes
inner
join ManagedEntity me on mes.ManagedEntityGuid
= me.ManagedEntityGuid
inner
join ManagedEntityProperty mep
on me.ManagedEntityRowId
= mep.ManagedEntityRowId
where mep.FromDateTime
= mes.ChangeDateTime
order
by mep.ManagedEntityRowId
Rgds
/Chris