RMAN ACTIVE DUPLICATE USING BACKUPSET IN 12C(NEW FEATURE) (Doc ID 1987193.1)

Last updated on APRIL 18, 2023

Applies to:

Goal

This Article explains RMAN ACTIVE DUPLICATE NEW FEATURE where RMAN ACTIVE DUPLICATE can be performed USING BACKUPSET.

Prior to Oracle Database 12c,  the ACTIVE DUPLICATE process used production database processes to send image copies across the network. This could be a time-consuming activity because the duplication process is directly proportional to the database size. Now, with 12c, the database duplication process has been improved, with the use of backup sets instead of image copies. As a result, the database size is relatively smaller because RMAN skips unused blocks, committed undo blocks etc. Plus, you can use compression and multi-section options for even faster duplication. Moreover, auxiliary channels from the destination site are used to PULL the backups over the network, as opposed to the PUSH method, used prior to 12c.

With Oracle Database 12c, a “pull” (or restore) process is based on backup sets. A connection is first established with the source database.The auxiliary instance then retrieves the required database files from the source database as backup sets. A restore operation is performed from the auxiliary instance instance. Therefore, fewer resources are used on the source database.

Both TNS connections are required on target and auxiliary instances.

Based on the DUPLICATE clauses, RMAN dynamically determines which process to use (‘push’ or ‘pull’). This ensures that existing customized scripts continue to function.

• When you specify USING BACKUPSET , RMAN uses the ‘pull’ method.
• When you specify SET ENCRYPTION before the DUPLICATE command, RMAN automatically uses the ‘pull’ method and creates backup sets. The backups sent to the
destination are encrypted.
• The SECTION SIZE clause divides data files into subsections that are restored in parallel across multiple channels on the auxiliary database. For an effective use of
parallelization, allocate more AUXILIARY channels.
• With the USING COMPRESSED BACKUPSET clause, the files are transferred as compressed backup sets. RMAN uses unused block compression while creating backups,
thus reducing the size of backups that are transported over the network.

Solution

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