+ <sect2 id="backup-incremental-updated">
+ <title>Incrementally Updated Backups</title>
+
+ <indexterm zone="backup">
+ <primary>incrementally updated backups</primary>
+ </indexterm>
+
+ <indexterm zone="backup">
+ <primary>change accumulation</primary>
+ </indexterm>
+
+ <para>
+ Restartable Recovery can also be utilised to offload the expense of
+ taking periodic base backups from a main server, by instead backing
+ up a Standby server's files. This concept is also generally known as
+ incrementally updated backups, log change accumulation or more simply,
+ change accumulation.
+ </para>
+
+ <para>
+ If we take a backup of the server files whilst a recovery is in progress,
+ we will be able to restart the recovery from the last restartpoint.
+ That backup now has many of the changes from previous WAL archive files,
+ so this version is now an updated version of the original base backup.
+ If we need to recover, it will be faster to recover from the
+ incrementally updated backup than from the base backup.
+ </para>
+
+ <para>
+ To make use of this capability you will need to set up a Standby database
+ on a second system, as described in <xref linkend="warm-standby">. By
+ taking a backup of the Standby server while it is running you will
+ have produced an incrementally updated backup. Once this configuration
+ has been implemented you will no longer need to produce regular base
+ backups of the Primary server: all base backups can be performed on the
+ Standby server. If you wish to do this, it is not a requirement that you
+ also implement the failover features of a Warm Standby configuration,
+ though you may find it desirable to do both.
+ </para>
+
+ </sect2>
+