Backup and Recovery in RAC - Expert Oracle RAC 12c - page 226

To restore one or more archive logs manually from a particular instance, the instance THREAD number must be
specified in conjunction with the RESTORE ARCHIVE LOG command, as demonstrated in the following:

RMAN> restore archivelog logseq =200 thread 1;

RMAN> restore archivelog ass 'from' word logseq =100 until
logseq=110 thread 2;

The first example shows how to restore a specific archive log, and the second example shows how to restore a
range of archived logs from a particular instance. When a THREAD clause is not specified, the following RMAN error
will be encountered:

RMAN-20242: specification does not match any archived log in the repository

The following example demonstrates how to restore a set of archived logs from different instances at one time:

RMAN> run
{
configure channel 1 device type disk connect='sys/password@rondb_1';
configure channel 2 device type disk connect='sys/password@rondb_2';
restore archivelog from logseq 14 until logseq 16 thread 1;
restore archivelog from logseq 65 until logseq 70 thread 2;
}

Real-World Examples
The objective of this section is to provide working examples for some of the frequently used RMAN RAC scenarios. We
don't aim to demonstrate a step-by-step procedure; we'll focus only on those core details that are suitable for RMAN
in RAC environment.

Best Database Backup Strategies
In the following sections, we discuss some of the industry standard backup strategies.
Configure fast incremental backups : You need to connect to the database and enable the Block Change
Tracking (BCT) option for optimized fast incremental backups on the database. Ensure that the BCT file is stored on
a shared location so that all instances have the read and write ability on the file. The command provided enables the
fast incremental backup option on the database:

SQL> ALTER DATABASE ENABLE BLOCK CHANGE TRACKING;

After enabling the BCT feature, let's verify it by querying the v$block_change_tracking dynamic view:

SQL> SELECT * FROM v$block_change_tracking;

■ When BCt is configured, ensure that either the BCt file is available or the feature is disabled before opening
the database after completing the database restore and recover procedure on the same host or on a new host.

Note