Square DBA – Oracle DBA Talk

What is the difference between Active Dataguard, and the Logical Standby implementation of 10g dataguard?

Here is an interview question I ran across on Ask Tom that I thought was perfect.
Active dataguard is mostly about the physical standby.

• Use physical standby for testing without compromising protection of the production system. You can open the physical standby read/write – do some destructive things in it (drop tables, change data, whatever – run a test – perhaps with real application testing). While this is happening, redo is still streaming from production, if production fails – you are covered.
• Use physical standby for reporting while in managed recovery mode. Since physical standby supports all of the datatypes – and logical standby does not (11g added broader support, but not 100%) – there are times when logical standby isn’t sufficient.
• It also permits fast incremental backups when offloading backups to a physical standby database