title: south, dry run, and transactions
body: <p>Can still run a data migration through a dry run and have it do all the data manipulations via the ORM API, but simply not commit (rollback) the transaction at the end?</p>
  
  <p>I understand that there are potential portability issues.  For example, Postgres not doing DDL inside a transaction.  But if I want to, can I still somehow do the above?</p>