Multi-region replication like Cassandra? Sort of a question because the last time I really looked around the release of PostgreSQL 9 there wasn't a solution.
Actually an interesting solution to this is using something like kafka-connect. Debezium specifically has libraries around pgsql -> pgsql replication using kafka + kafka-connect that work shockingly well. The lag is not much different than traditional replication but you can have a single primary that kafka-connect is pulling into kafka, and a gazillion replicas off that single stream.
