Chapter 10. Implementing Database Backups
ORACLE DATABASE 10 G: ADMINISTRATION I EXAM OBJECTIVES COVERED IN THIS CHAPTER:
Describe the basics of database backup, restore and recovery.
Configure ARCHIVELOG mode.
Configure a database for recoverability.
Database Backups
Create consistent database backups.
Back up your database without shutting it down.
Create incremental backups.
Automate database backups.
Monitor the flash recovery area.
Describe the difference between image copies and backup sets.
Describe the different types of database backups.
Back up a control file to trace.
Manage backups.
NOTE
Exam objectives are subject to change at any time without prior notice and at Oracle's sole discretion. Please visit Oracle's Training and Certification website (http://www.oracle.com/education/certification/) for the most current exam objectives listing.
Oracle Database 10g (Oracle 10g) makes it easy for you to configure your database to be highly available and reliable. In other words, you want to configure your database to minimize the amount of downtime while at the same time being able to recover quickly and without losing any committed transactions when the database becomes unavailable for reasons that may be beyond your control.
As a database administrator, your primary goal is to keep the database open and available for users, usually 24 hours a day, 7 days a week. Your partnership with the server's system administrator includes the following tasks:
Proactively solving common causes of failures
Ensuring a high level of hardware redundancy
Increasing availability by using Oracle options such as Real Application Clusters (RAC) and Oracle Streams (an advanced replication technology)
Decreasing the mean time to recover (MTTR) by setting the appropriate Oracle initialization parameters and ensuring that backups are readily available in a recovery scenario
Minimizing or eliminating loss of committed transactions by using archived redo logs, standby databases, and Oracle Data Guard
NOTE
RAC, Streams, Data Guard, and standby databases are beyond the scope of this book, but are covered in more detail in advanced Oracle courseware.
In this chapter, we will first describe the components that you will use to minimize or eliminate data loss in your database while at the same time keeping availability high: checkpoints, redo log files, archived redo log files, and the Flash Recovery area. Next, we will show you how to configure your database for recovery, including a discussion of ARCHIVELOG mode and other required initialization parameters. Once your environment is configured, you will need to know how to actually back it up, using both operating system commands and the RMAN utility. Finally, we will show you how to automate and manage your backups as well as how to monitor one of the key components in your backup strategy: the Flash Recovery area. In Chapter 11, "Implementing Database Recovery," we will show you how to use the files created and maintained during your backups to quickly recover the database in the event of a database failure.
Oracle's GUI administration tool, the Enterprise Manager (EM) Database Control, makes backup configuration and performing backups easier than in any previous release of Oracle. Most, if not all, of the functionality available with the command-line interface is available in a GUI interface to save time and make backup operations less error prone.