Refer this http://www.oracle.com/technetwork/database/features/availability/dataguardgoldengate-096557.html
I have data-guard for disaster recovery and now my management planning to do more like implement Golden gate. My question is when you can protect your data and offload pressure on primary database by maintaining active data-guard why someone need to go for golden gate?? Please share your experience for using Golden Gate over Data guard!!
One more thing, what is meant by when someone using terms standby , dataguard and active dataguard?? Aren't all they same??Active Dataguard is a feature wherein the standby database would be placed in open read-only mode and the recovery (MRP/log applying) would be in progress. This is called as active dataguard and the standby would be in sync with the primary. The standby database when kept in open read-only mode can be used reporting purposes, to run select queries. So, you would be having a feature of using the standby database as a reporting database and in the same time the standby would be applying the logs from the primary. This feature is available only from 11g.