问题:

I am looking at the Activty Monitor for SQL Server 2005 and we have some processes that are taking up large amounts of the CPU. When I look at what is trying to be run I get:

set transaction isolation level  read committed

This code is not coming from any of our applications.

What is causing it?

What should be done?

回答1:

Look at sys.dm_exec_sessions and sys.dm_exec_connections for the session ids that take up CPU. You'll find the application name, host name and process id of the client.

回答2:

This is the default transaction isolation level for ADO.NET and most OR/M frameworks. Chances are this is in fact coming for your code, you just don't know it.

I think this is the wrong question to ask anyways - the real question is, why is this rather common TSQL instruction causing your database CPU to spike?