The temporal state of the transaction is represented in the database, too. Just that it happens to be in the Session table, which you access via CGI::Session. Makes maintenance easier, too, IMO. However CGI::Session wants to store the data is its problem. (Well, mostly - you can choose the approach, which could be via a Storable blob.) But the key point is that you don't need to track a bunch of files, ensure they're cleaned up, etc. The session manager can do that for you.