Performance impact of Extended Events filter [like_i_sql_unicode_string]
I would say you don't need all the start events, just the completed. I don't see that you are capturing data just for the SCOM database either. Extended events can cause an overhead just near to what SQL Server traces will depending on what you are trying to capture.

You are basically capturing every query that comes across the server and telling it to wait so you can first check the text of the query and then grab information through the extended event session, then letting it complete.

As well the constant activity SCOM has, depending on environment configuration, it is likely to have an extreme performance hit either with trace or extended events. I would suggest looking at the plan cache for those types of queries initially. However you might try adding more filters to your session such only grabbing a sample of data from active sessions and then also only capturing data for the particular database. That would look something like this through the GUI:



Or code your WHERE clause would look something like:

WHERE ((([package0].[divides_by_uint64]([sqlserver].[session_id],(5))) 
   AND ([package0].[greater_than_uint64]([sqlserver].[database_id],(4)))) 
   AND ([package0].[equal_boolean]([sqlserver].[is_system],(0))))) 


This would capture I think 20% of the active sessions for that database at any given time. However if you want all events then you would have to suffer the overhead of that action.

With it being a Microsoft product I would not be to concerned with what queries it is producing. If it is experiencing performance issues you should follow Microsoft guidelines for the product or consult Microsoft support.