24.3. Continuously Running Replication Server

A continuously running replication server allows the backup server to answer read-only queries while the master server is running. It receives a continuous stream of write activity from the master server. Because the backup server can be used for read-only database requests, it is ideal for data warehouse queries.

Slony is an example of this type of replication, with per-table granularity. It updates the backup server in batches, so the replication is asynchronous and might lose data during a fail over.