Standby database v. advanced replication.

I have a requirement for a new 24x7 mission critical database. Occasional outages of < 5 minutes can be tolerated, but no longer. The fail-over options being considered are: (1) a standby database, and (2) advanced replication. OPS is not being considered because it does nothing to provide fast recovery from a media failure.

I'm leaning towards a standby database because I've had bad experiences in the past with Oracle snapshots. Unless I'm mistaken, that's the same technology that advanced replication is based on. Oracle would always lose track of the fact that a fast refresh could be done and try to do a full refresh. Some of the tables in this database will contain up to 20m rows and 8g of data. Way too much to attempt a full refresh.

Standby databases look like they're easier to implement and might be more reliable, but switching back I'm told is a problem.

Has anyone out there made a similar comparison? What would your recommendation be? If you have any experiences to relate I'd like to hear about them.

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Chuck Hamilton
Oracle DBA