I am still using Tableau 7.xx while I wait for my organization to push Tableau 8 out enterprise wide. I set up my connection as an incremental refresh, then realized I had a problem with a formula in the underlying data (it is in Excel). I had to refresh the connection which then created a full extract. How can I go back to an incremental refresh? If the answer is that I need to build a new connection, how can I do that then replace the existing one so I don't lose all the calculated fields I've created in Tabelau?