Far Sync is used to extend zero data loss protection to a remote standby database and avoid the impact to primary database performance of WAN network latency. A primary database ships synchronously to a light-weight instance referred to as a far sync instance (a control file and log files, no data files and no media recovery). The far sync instance then forwards the redo asynchronously to a remote standby database that is the failover target. Additional Far Sync features include the ability to directly service up to 29 remote destinations, and the ability to utilize Oracle Advanced Compression to compress redo for efficient transmission across a WAN. Far Sync is transparent to the administrator with regards to Data Guard role transitions. The same switchover or failover command used for any Data Guard configuration will transition any remote standby databases served by a far sync instance to the primary production role.
Business Benefit: Zero data loss protection can be achieved across long distances. The far sync instance is located within a distance of the primary database where synchronous transport does not impact application performance. Far Sync handles all communication with remote standby databases and is transparent when executing a zero data loss failover. Far Sync also offloads the production database of the overhead of servicing multiple remote destinations and redo transport compression.
