Using Warm Standby Servers v6.2
When many organizations wish to improve the availability of their data, a cost effective solution is often the use of warm standby servers. These are database servers kept up to date with the online system through replication that can be brought online quickly in the event of a failure in the production system. Warm standby servers can also be used for regular maintenance by gracefully switching over to the standby server so that the production server can be brought offline for regular maintenance.