MySQL -> PostgreSQL
I just changed the Greenpeace instance of the latest Rhubarb code over from MySQL to PostgreSQL. I had a bit of trouble getting the existing instance to work with either suggested (by rails) PostgreSQL Ruby bindings, both gave errors about not being able to find PGConn. Eventually I just recreated the instance from scratch and it works now.
I tried exporting the data from MySQL and importing into PostgreSQL but even using the tools provided in the contrib/mysql directory of PostgreSQL (7.4.8) I kept getting syntax errors. Since the data was just test data I didn't bother trying to fix these. I recreated the user accounts so logins should still work but now theres no data in the system.
Oh, and it's deliberately configured NOT to send email at the moment.