This is covered in at least the 11g docs, essentially its the same as HA for any other db that supports mission critical apps, namely some version of the MAA with standby databases, switchover and sensible connection strings for the omses. Whether it fits all possible scenarios is questionable, however if you can't do a rolling upgrade of your repository, then you probably can't do real applications either. Niall Litchfield On Jun 24, 2010 4:47 PM, "Guillermo Alan Bort" <cicciuxdba@xxxxxxxxx> wrote: Distributed RAC is supported for relatively close locations, and we are deploying GC around the world. the DataGuard for repository is being considered, however that only safeguards against emergency outage... what about planned outage? is there a way to avoid it? (other than never applying a patch, of course) Alan.- On Thu, Jun 24, 2010 at 12:21 PM, Storey, Robert (DCSO) < RStorey@xxxxxxxxxxxxxxxxxx> wrote: > > W...