RelationalDBDesign 





Database Backup   «Prev  Next»
Lesson 1

Introduction to Oracle Recovery Manager

The most important job for an Oracle database administrator (DBA) is the backup and recovery of Oracle databases. In the first course in this series, you learned what could happen when you do not take this role to heart. As a DBA, you can almost get away with a poorly performing database, as long as the data within the database is correct. After all, poor performance can be eliminated with tuning, Oracle Sql Tuning. But if the data is not available or cannot be recovered, your ability to restore the original state will be in jeopardy.

Backup and Recovery Features for Oracle 11g Release 2

The following Backup and Recovery features are new in Oracle Database 11g Release 2
  1. Oracle Secure Backup (OSB) Cloud Module
    Users can take advantage of the Internet-based data storage services offered by Amazon Simple Storage Service (Amazon S3) for their RMAN backup and recovery tasks. The OSB Cloud Module interface extends the Amazon S3 functionality and provides an easy-to-manage, cost-efficient, and scalable alternative to maintaining in-house data storage and a local, fully configured backup infrastructure.
  2. DUPLICATE Database Command Enhancements
    Users can duplicate a database without connecting to a target database. The only requirements for this operation are a connection to a catalog and an auxiliary database. This new functionality is useful when the target database is not always available. Users can also duplicate a database without connecting to a target database and a recovery catalog. In this case, the only requirement is that you provide a disk backup location where RMAN can find all the backups, data file copies, archived logs, and control file copies for database duplication. This database duplication enhancement is helpful when it is not possible to connect to the target database and the recovery catalog. When you duplicate from a target database, RMAN determines if any excluded tablespaces contain SYS-owned objects, materialized views, and identifies tablespaces that are not self-contained before starting any duplication operations.


Recovery Manager

Oracle contains a utility called Recovery Manager, or RMAN, to manage the backup, restoration, and recovery of Oracle database files. If you are managing multiple databases, RMAN is the tool for you. This module introduces Recovery Manager and its components.
  1. By the end of this module, you will be able to:
  2. Discuss the purpose and features of Oracle Recovery Manager
  3. Review the basic components of RMAN
  4. Discuss the preparation involved in using RMAN
  5. Discuss the role of Backup Manager as a graphical user interface (GUI) tool for backup and recovery
  6. Discuss how backup sets are used within Recovery Manager
  7. Discuss the concept of image copies
  8. Discuss the role of the recovery catalog
  9. Demonstrate how to create a recovery catalog
For more detailed information, refer to the Oracle Server Backup and Recovery documentation. You can find this on your Oracle release CDs. This documentation can also be found online at the Oracle Web site refer to the Resources page for additional information. Several third-party books on the topic can also provide practical examples and can be found on the Resources page. In the next lesson, you will learn the basic features of Oracle Recovery Manager.

Media Management Considerations

The RMAN utility in Oracle Database 12c focuses on the best way to leverage disk backups as the media recovery solution. With the price of disks falling, massive storage area networks (SANs) have found a permanent place in many datacenters. With the business evolving toward cheaper and larger disks, upgrades in RMAN functionality (such as the Fast Recovery Area) were implemented to make best use of the available storage space.
It is a logical progression for the RMAN backup utility, and, of course, writing to disk is something that the Oracle Database is extremely good at. Therefore, any time it gets to leverage its disk-writing muscle, the RDBMS will do so for performance improvements.
But, for many customers, the world of unlimited disk storage has not arrived. For many, the size of the database, or its location, keeps it from being backed up to disk. Or, there still may be a business requirement to make a copy of the data and archive it offsite. So what does RMAN do if it needs to write to good, old-fashioned tape?
Tape backups of the Oracle database require third-party assistance. This is primarily due to the disparate nature of the different sequential media subsystems that are on the market and that are used every day. Instead of trying to employ different system calls for each different type of tape device, RMAN’s development team decided to employ those software vendors that already earn a living by selling products that can read and write from tape.
Oracle has its own media management software solution, Oracle Secure Backup (OSB). OSB is a fully integrated RMAN-to-tape solution that does not require any thirdparty vendor software plug-in, and OSB has come a long way since its introduction in 10gR2. However, many customers will continue to purchase a license from any of the number of certified backup providers that have an Oracle RMAN plug-in.