Among the features introduced in Oracle 11g is Edition Based Redefinition. This feature enables us to have multiple active versions of database objects in order to facilitiate online application upgrades.
Prior to this release, if an application used stored procedures or triggers, upgrades required database downtime in order to redefine database objects. This new feature facilitates zero down-time application upgrades but it is a complicated feature and using it can be difficult.
Our colleague, Dennis Heltzel, is writing a series of blog posts about the nuances of using this important new feature. The following four posts cover the general concepts of Oracle Editioning and discuss some important limitations and problems that he found while implementing it.
I hope you find these helpful:
https://dheltzel.wordpress.com/2013/05/25/editioning-in-an-oracle-database-concepts/
https://dheltzel.wordpress.com/2013/05/29/editioning-with-synonyms/
https://dheltzel.wordpress.com/2013/06/05/editioning-views/
https://dheltzel.wordpress.com/2013/06/08/editioning-new-data-dictionary-views/