Oracle 11g does include an interesting feature, the feature to upgrade your applications in a well ordered and controlled manner. You can test the application before you GoLive with it, and you do not loose any information. The users can do their job in the pre-upgraded version whilst you change the new version, test it and change to it.
Edition-Based Redefinition is, Tom Kyte says, the most important thing that happened since we got PL/SQL in the database. And, Mr Kyte always - in my opinion - knows what he says.
So, go for the manual pages and study EBR. You can have editions on SYNOMYNS, VIEWs and PL/SQL-modules in the database. And there are some rules to consider when you try this out. So carefully study the steps in the manual.
Demo App for REST enabled SQL
2 months ago