Before I do an upgrade I always ask for the size of the TFS database set. It provides me the information on how long an upgrade might take. The queries below, also provides information of attachments that might be taking up extra disk space. By reducing the overall database set, the whole upgrade process will go faster. Plus, it is a good time to do some house cleaning.
If you use the Attach/Detach process to do an TFS 2013 upgrade, you don’t get progress status bar as you would using the Upgrade wizard. If you have a large database upgrade to perform, it is good to see some type of progress of the upgrade process.Below is some select T-SQL command that you can run to see what job is being executed.