title: Query slow when executing with actual execution plan
body: <p>I'm trying to optimize a stored procedure. When ran in management studio, it takes about 40 seconds. When ran with the "Include actual execution plan" toggled on, it takes over 10 minutes, sometimes longer. During those 10 minutes, SMSS.exe hogs a whole CPU core, so possibly a client issue.</p>
  
  <p>The stored procedure is fairly big, over 2k rows, so the query plan is also quite large. This happens only for the SP, on multiple machines. It doesn't happen every time, it seems to come and go. Sometimes, when the cancel button is clicked during the execution, management studio comes up with a semi-random nondescript error message.</p>
  
  <p>SMSS 10.50.1600.1 , SQL 2008 R2</p>
  
  <p>Any ideas?</p>