title: Join table or duplicate data?
body: <p>I am looking for real-world implementations:
  Use case is this -> I store the user login details (mode, session, browser, OS, etc) in the session table. I have a activity table where i track activities that FKs to session table.</p>
  
  <p>Now when a user takes an activity on an object like "Create a photo" I want to include all the details with it like the browser the user used to upload the image, his IP address, etc. So all the fields in the session table. </p>
  
  <p>On a good day you would normally FK the session_Id with the photo table and join to pull that data. But what if i duplicate the same 6-7 colunms in the photo and each object table to prevent joins/FKs? </p>
  
  <p>I want to know what works in the real world on large scale user content sites.</p>