A Far Sync Standby Database is a cascading Standby Database that acts as a Redo Log Repository for a Terminal Database. It does not contain any datafiles. Only Log Transport Services are active on a Far Sync Standby Database. The Advantage of a Far Sync Standby Database is that it can be a local ArchiveLog Repository for the Primary Database acting in Maximum Availability Mode where the Physical or Logical Standby Database can be on a far remote Site.

Creating a Far Sync Standby Instance

You can prepare your Environment for a Far Sync Instance the same Way like for a Physical Standby Database. Instead of a Physical Standby Controlfile we are creating a Far Sync Standby Controlfile from the Primary Database and use this Controlfile to mount the Far Sync Instance:

SQL> alter database create far sync instance controlfile as '[File Specification]';

You can then setup Log Transport Services to the Cascaded Standby just like for normal Cascaded Standby Databases.

Data Guard Broker and Far Sync Standby Database

The Data Guard Broker also supports Far Sync Standby Databases and Cascaded Standby Databases. You can add a Far Sync Standby to your Data Guard Broker Configuration using:

DGMGRL> add far_sync [Name] as connect identifier is [Connect Identifier];

Then set the Data Guard Broker Property ‘RedoRoutes’ for the Databases accordingly. You can find an Explanation about ‘RedoRoutes’ in