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Recovery Manager (RMAN) Enhancements in Oracle Database 12c Release 1 (12.1)
This article provides an overview of the recovery manager (RMAN) new features and enhancements introduced by Oracle 12c Release 1 (12.1). Several of the sections are covered in separate articles, so they are linked from here.
- Multisection Image Copies and Incremental Backups
- Network-Enabled RESTORE
- RMAN Command-Line Interface Enhancements
- Storage Snapshot Optimization
- RMAN Virtual Private Catalog
Covered in other articles.
- Database Duplication Enhancements
- Backup and Recovery of CDBs and PDBs
- SYSBACKUP Privilege
- Table-Level Recovery From Backups
- Cross-Platform Backup and Restore (Not covered yet)
Related articles.
- Multitenant : Backup and Recovery of a Container Database (CDB) and a Pluggable Database (PDB) in Oracle Database 12c Release 1 (12.1)
- Administrative Privileges and Job Role Separation in Oracle Database 12c Release 1 (12.1)
- Recovery Manager (RMAN) Table Point In Time Recovery (PITR) in Oracle Database 12c Release 1 (12.1)
- Recovery Manager (RMAN) Database Duplication Enhancements in Oracle Database 12c Release 1 (12.1)
- RMAN Quick Links : 8i, 9i, 10g, 11g, 12c, All Articles
Multisection Image Copies and Incremental Backups
In previous releases it was only possible to perform multisection backups using conventional backup sets. In Oracle 12c, it is also possible to use multisection backups for image copy and incremental backups.
In all three cases, multisection backups are triggered by the addition of the SECTION SIZE
clause of the BACKUP
command, which indicates the size of the fragment to be processed by each slave. If the file size is smaller than the SECTION SIZE
value, a multisection backup of that file is not performed.
# Backup set. BACKUP SECTION SIZE 400M DATABASE; # Image copy. BACKUP AS COPY SECTION SIZE 400M DATABASE; # Incremental and incrementally updated image copy. BACKUP INCREMENTAL LEVEL 1 SECTION SIZE 400M DATABASE; BACKUP INCREMENTAL LEVEL 1 FOR RECOVER OF COPY WITH TAG 'mydb_incr_backup' SECTION SIZE 400M DATABASE;
Network-Enabled RESTORE
Restore and recovery operations can be performed directly over a network without the need to manually transfer files. This is done using the FROM SERVICE
clause, which is used to specify an entry in the "tnsnames.ora" file pointing to the service the data should be sourced from. The documentation discusses two scenarios where this might be useful.
Using a file from a physical standby database to restore a missing/damaged file in the primary database.
RESTORE DATAFILE '/u01/oradata/primary/hr.dbf' FROM SERVICE standby_tns;
Refreshing a physical standby database from a primary database. This performs an incremental backup of the primary database and uses it to refresh the standby database.
RECOVER DATABASE FROM SERVICE primary_db;
There are some additional post-recovery steps to take when doing a network refresh of a standby database, described here.
RMAN Command-Line Interface Enhancements
The command line interface of RMAN has been simplified with respect to using SQL. Previously, SQL commands had to start with the SQL
keyword and needed to be enclosed by quotes. In Oracle 12c this is no longer necessary for most commands. You also have the option of using the SQL
keyword, without quoting the subsequent command.
# Pre-12c SQL "ALTER SYSTEM SWITCH LOGFILE"; # 12c : Using SQL keyword. SQL ALTER SYSTEM SWITCH LOGFILE; # 12c : No SQL keyword. ALTER SYSTEM SWITCH LOGFILE;
You can also do queries in a similar way to SQL*Plus.
RMAN> SELECT name FROM v$database; NAME --------- CDB1 RMAN>
The SQL commands available from RMAN directly are described here.
Storage Snapshot Optimization
Oracle 12c supports backups taken using 3rd party storage shapshots, without the need to put the database in backup mode. There are some requirements the storage must adhere to for this functionality to be supported, listed here.
Recovering using a snapshot performed in this manner requires the use of the SNAPSHOT TIME
clause.
RECOVER DATABASE UNTIL TIME '04/25/2016 12:00:00' SNAPSHOT TIME '04/25/2016 13:00:00';
RMAN Virtual Private Catalog
A virtual private catalog is an RMAN catalog implemented using Virtual Private Database (VPD), so it appears as multiple independent catalogs. This can be useful when a single catalog is shared between multiple teams, each managing different systems. This functionality was introduced in Oracle 11g.
In Oracle 12c (12.1.0.2), the use of the virtual private catalog functionality is now restricted to the Enterprise Edition of the database. You can read more about virtual private catalogs here.
For more information see:
- Changes in This Release for Backup and Recovery User's Guide (12.1)
- Multitenant : Backup and Recovery of a Container Database (CDB) and a Pluggable Database (PDB) in Oracle Database 12c Release 1 (12.1)
- Administrative Privileges and Job Role Separation in Oracle Database 12c Release 1 (12.1)
- Recovery Manager (RMAN) Table Point In Time Recovery (PITR) in Oracle Database 12c Release 1 (12.1)
- Recovery Manager (RMAN) Database Duplication Enhancements in Oracle Database 12c Release 1 (12.1)
- RMAN Quick Links : 8i, 9i, 10g, 11g, 12c, All Articles
Hope this helps. Regards Tim...