Top 10 topics for Data Guard on Metalink by usage

Metalink Knowledge Base Data Guard top 10 notes by usage

1. 10.2 Data Guard Physical Standby Switchover(751600.1)
   
2. Data Guard Support for Heterogeneous Primary and Standby Systems in Same Data Guard Configuration (413484.1)
   
3. Applying Patchset with a 10g Physical Standby in Place (278641.1)
   
4. The Gains and Pains of Nologging Operations (290161.1)
   
5. Steps To Create Physical Standby Database (736863.1)
   
6. Oracle10g: Data Guard Switchover and Failover Best Practices (387266.1)
   
7. MAA - Creating a RAC Physical Standby for a RAC Primary (380449.1)
   
8. Script to Collect Data Guard Primary Site Diagnostic Information (241374.1)
   
9. MAA - Data Guard Redo Transport and Network Best Practices (387174.1)
   
10. Creating a 10gr2 Data Guard Physical Standby database with Real-Time apply (343424.1)
    

As you can see the 2nd place is for Heterogeneous standbies and also MAA
best practices are definitely on the edge of usage.
I think it shows that standby and Data Guard configuration are used not only to
increase availability of systems but also to migrate from one platform to another
as for example it is possible to migrate from Windows 32-bit to Linux 64-bit
with Oracle 11g and minimal downtime.

Have a good day!