Question

While looking at the Activity Monitor in SQL Server, I notice that under the “Recent Expensive Queries” tab, the “Executions / min” column seems to balloon to a much higher number than it should be.
What does this number actually mean? Is it literally how many times a SQL Query is performed in a minute, or does this number represent something else?
Thanks in advance for the help!

Answer 1

The “Expensive Query” you are analyzing might be using other subqueries (Let’s say 10). Then could it be your “Executions / min” count is 10 times higher? Since an execution plan is recompiled for every subqueries?

Found this answer here:

The Execution/Min means the executions per minute for the query, the execution_count column in sys.dm_exec_query_stats indicates the number of times that the plan has been executed since it was last compiled. It is normal that the value of execution_count is not equal to the Execution/Min, since if the execution plan of your query recompiled or regenerated during execution, then the execution_count will be reset to 0 and recount. For instance, if this insert statement included into a transaction block, then the execution plan’s recompile might be caused by the other statement’s execution plan recompiled, so the execution_count will be reset to 0 and recount.

Please refer to the below links for more detail information:

sys.dm_exec_query_stats: http://msdn.microsoft.com/en-us/library/ms189741.aspx
Activity Monitor: http://msdn.microsoft.com/en-us/library/cc879320(v=SQL.100).aspx

Thanks, Weilin Qiao