Google "Postgres BDR". It is new, but it allows you to replicate changes on master to another master. With some configuration it can even change replicated data.
Thank you. I believe that bidirectional replication will solve the ETL problem, if it can be configured to stream from a replica in the source/oltp cluster (to minimize network IO on the source cluster master db) to the master of the destination/olap cluster. The olap master can mirror the oltp data, but also use triggers to denormalize oltp tables.
One thing I'd like to see is the ability to sanitize/munge data from the source cluster before it is sent to the destination cluster, for masking sensitive data in the source cluster (PCI, HIPAA, etc).
One thing I'd like to see is the ability to sanitize/munge data from the source cluster before it is sent to the destination cluster, for masking sensitive data in the source cluster (PCI, HIPAA, etc).