title: performance of ActiveRecord SessionStore
body: <p>How big is the performance penalty switching from the cookieStore to the ActiveRecord SessionStore?</p>
  
  <p>By default Ruby on Rails uses the CookieStore. But it has the disadvantage that the client needs to have its cookies enabled.</p>
  
  <p>Switching to the Active SessionStore seems to solve that problem. I'm considering switching.</p>
  
  <p>I read that performance is worse using the ActiveRecord SessionStore. But what is worse? Will a user notice this, or is it a matter of milliseconds? Anybody has seen benchmark results comparing the 2 options?</p>
  
  <p>Any other reasons (not) to switch to the ActiveRecord SessionStore?</p>