The following article describes the new features and enhancements that were added in Oracle Data Guard 12c Release 1.
Oracle Data guard overview:
Oracle Data Guard provides solutions to maximize high availability of Oracle databases. Oracle Data Guard maintains one or many secondary databases as alternatives to the primary production database in order to protect the primary database from loss, corruptions, disasters , errors.
Oracle Data Guard also can be used for load balancing: the standby can be opened for queries, testing, reporting.
Database administrator can choose either manual or automatic failover of production to a standby database.
What’s New in Oracle Data Guard 12cR1?
1- Far Sync Standby
2- Cascade a Standby Database in Real-Time
3- Using DBMS_ROLLING to Perform a Rolling Upgrade
4- SYSDG Privilege
5- Online Standby Datafile Movement
6- Recover Standby database using service names
You can find more details about the above new features here: 12c_DataGuard_New_Features