From where exactly does DPA pull its data? Is there an agent on the DB Server? WMI?
Is it a good reflection of the SQL server engine point of view? Thank you.
@[Deleted User] DPA does not require an agent, it runs T-SQL to query DMVs and return data. WMI collection was turned off starting with version 10 (although you can enable this if desired). DPA also creates an xEvent session to capture deadlock details.
This architecture allows for DPA to have a minimal footprint. The metrics returned are a great way to see what is happening inside of the database engine.
HTH
Noting for the record:
DMV Dynamic Management Views
T-SQL .Transact SQL
https://docs.microsoft.com/en-us/sql/relational-databases/system-dynamic-management-views/system-dynamic-management-views?view=sql-server-ver15
