Upgrading critical applications can be very difficult. One of the main problem is long downtimes cannot be periodically scheduled. Therefore, for such applications, it is desirable to implement online upgrades. This requires that the application in question, as well as any software used by the application (e.g. the database engine) all support online upgrades. As of Oracle Database 11g Release 2, With edition-based redefinition, Oracle Database offers real support for implementing online upgrades.
EDITION BASED REDEFINITION (EBR) in Oracle database - modern technology and methodology to apply patch without any downtime. Discuss the challenge of zero downtime patch application and shows how EBR can meet the challenge. EBR is free and not a priced option nor is it even restricted to just the Enterprise Edition. Any licensed edition of Oracle Database 11g Release 2 or later is entitled to use EBR.