Till Oralce 10g, Using a combination of Data Guard, restore points, and Flashback Database, a physical standby database can be opened temporarily in read/write mode. From Oracle 11g, we can use snapshot standby. What is the difference
between 10g method and snapshot standby?
I think they are same with only difference is that in 10g you need to create guaranted restore point manually and in 11g this is done automatically when you convert physical standby to snapshot database.
Apart from the easier way to get that Snapshot Standby in 11g, there is one big difference:
In 10g, the Redo Transport from Primary to Standby had to be stopped during the 'Snapshot Standby' (the term did not exist in 10g), leaving the Primary at risk in case of a disaster.
This is no longer the case with 11g: We can ship redo to the Standby during its Snapshot Standby role.