Central-to-Backup Configuration
In a central-to-backup or standby design scheme, illustrated in the following figure, if a source database fails, an emergency backup database is available to resume activity.
Using central-to-backup with a peer-to-peer design scheme allows Ingres Replicator to ensure data is replicated to the failed database upon recovery; consistency is thereby restored across databases. Without a peer-to-peer scheme, a DBA must use a copy from a read-only backup and perform manual recovery.
Note: A two-database peer-to-peer backup (or standby) scheme is identical to a two-database peer-to-peer, except that in the standby scheme the backup database is normally not accessed by users.
The central-to-backup configuration can maximize database availability across an enterprise without sacrificing fault tolerance. A central-to-backup configuration can also be used for continuous (24 x 7) operation. When database maintenance tasks such as recreating indexes are necessary on the main database, the users can be switched to access the secondary copy.
