PgSQL Replication
This page describes how to set up direct replication with pgSQL. Generally, replication allows having two database servers (typically one for data entry and one for reporting) that stay synchronised. Concretely, when data is added, deleted or updated on the master server, the changes get immediately replicated on the slave or standby server. The standby database is read-only, i.e. no changes can be made directly there - only changes on the master are being replicated. Currently (August 2014) this mechanism is only in place at MACCA in Kabul.