Each site is capable of processing independently from the other remote sites, and the addition of a new site will not affect the overall system. While each site maintains its own unique identity and control, it functions as a part of a unified federation such that other remote sites can access information from it in a seamless fashion.
Continuous operation also refers to the ability of each node to be available to the overall system 24 hours per day, seven days per week. To accomplish this goal, remote sites may have a "hot backup" tool such as the Oracle Enterprise Backup Utility (EBU) or the Oracle8 Recovery Manager (RMAN) to back up the database while it remains available for update.
Other Oracle continuous-operation tools include Oracle Parallel Server and Oracle snapshots.