[Aug. 8, 2012 Update: Added additional details about logical standby and Oracle Streams]
[Aug. 24, 2011 update: Clarified description of AutoConfig dependency when enabling EBS failover environments]
Oracle Data Guard allows you to create standby databases for disaster recovery. Oracle Data Guard Broker provides an easy interface to configure standby databases and to perform role transitions with a single command for switchover and failover. It logically groups the primary and standby databases into a broker configuration that allows the broker to manage and monitor them together as an integrated unit. Oracle Data Guard Broker can automate the following operations:
There are two interfaces to manage broker configurations:
If you've implemented standby databases as part of your EBS disaster recovery or business continuity strategy, we'd recommend that you consider using Data Guard Broker, too. We've provided step-by-step configuration instructions to use the Data Guard Broker [DGMGRL] tool to manage Physical Standby databases for E-Business Suite Release 12. For detailed instructions, see:
Failover with E-Business Suite environments is not automatic. E-Business Suite environments must be failed over manually due to the need to run AutoConfig to reconfigure services on the failover site.
What about logical standby or Oracle Streams?
Neither logical standby nor Oracle Streams can be used for replicating E-Business Suite databases. As documented in Maximum Availability Architecture and Oracle E-Business Suite Release 11i (Note 403347.1):
The process that mines the redo to create SQL statements for a logical standby cannot handle all data types and actions provided by the Oracle database. The E-Business Suite uses some of those “unsupported” data types. Thus, the Applications development group does not support the use of logical standby for an E-Business Suite implementation.