title: the transaction log for database 'tempdb' is full due to 'ACTIVE_TRANSACTION
body: <p>I'm running same query in two different windows of the same server.
  the only difference is : the query that is throwing above error has got 'index' on the temporary tables.</p>
  
  <p>The query w/o index on temporary tables is working fine. Please explain how could index be a reason for this error?</p>