Just a quick note to point a MOS note which I found out yesterday . I already tweeted about it and it has been retweeted many time by my follower, but for wider audience I decided to write a blog post as well.
As you may already know, to migrate databases between different endian formats, using RMAN Transportable Tablespaces is an option but for this option to work, you need to have a downtime since tablespaces needs to be read only, and this downtime can be very long duration depending on the data size.
To sort this problem for migrations to Exadata platform (method only supported on Exadata) Oracle now brought incremental backup availability for TTS, till Oracle puts this as a public document (or somebody post about the steps) you need a MOS access to see the method.
For more information.
Reduce Transportable Tablespace Downtime using Cross Platform Incremental Backups [ID 1389592.1]
In my humble opinion, Oracle better decide to support this on other platforms since method should not have anything to do with Exadata spesific other than being supported (don’t know any rman method which needs Exadata spesific features)