Would a complete refresh of updatable mview will perform both way replication? What if since the last refresh the same field was updated in both envs? Which one will prevail?if you look at Concepts http://docs.oracle.com/cd/B19306_01/server.102/b14226/repmview.htm
An updatable materialized view log (USLOG$_materialized_view_name) is used to determine which rows must be overwritten or removed from a materialized view during a fast refresh. A read-only materialized view does not create this log, and Oracle does not use this log during a complete refresh because, in this case, the entire materialized view is replaced.I would experiment first with creating a similar test UMV, done updates on both sides and do complete refresh.
It is not clear to me what is a purpose of "a script that would check differences and execute updates, some kind of convoluted manual replication solution" while you are already using the updateable fast MV, which is itself kind of "difference based update"?2. Why does anyone care if after all this time no one noticed that the MV was hopelessly out of date?Up to now there was someone that would run a script that would check differences and execute updates, some kind of convoluted manual replication solution,