Executive Summary: Don’t bother running multiple SQL Server instances. Instead, obtain the performance metrics you need by using SQL Server 2005’s built-in sys.dm_exec_plan_attributes DMV.

I recently spoke with someone who was thinking about creating multiple SQL Server instances on his server and placing one database in each instance. You might wonder why he would want to do such a thing. He was concerned about system performance and thought that by placing one database in each instance, he could monitor them independently so that he’d know which ones were using the most resources.

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