Performing Backups and Recovery with your 10g Database

The next few blogs will discuss the new features that have been provided to streamline backup and recovery tasks. It utilizes the Flash Recovery Area, a feature that unifies related recovery files within a specific area and simplifies database administrator tasks. In previous releases of the Oracle database when you backed up the database using incremental backups, RMAN had to examine the entire data file to determine which blocks had changed. In Oracle Database 10g, you can create a block change-tracking file that records the blocks modified since the last backup. RMAN uses the tracking file to determine which blocks to include in the incremental backup. The change-tracking file enables RMAN to make the incremental backup time proportional to the amount of content modified since the last backup instead of being proportional to the size of the data files being backed up.

In Oracle Database 10g, flashback functionality has been extended. The Flashback Database feature provides a way for you to quickly revert your entire Oracle database to the state it was in at a past point in time. In addition to flashback operations at the database level, it is also possible to flash back an entire table. You can also quickly recover a table that has been inadvertently dropped. The existing flashback query capabilities have also been enhanced.


Configuring the Flash Recovery Area
The flash recovery area is a unified storage location for all recovery related files and activities in an Oracle database. All files that are needed to completely recover a database from a media failure are part of the flash recovery area. The recovery related files that can be created in the flash recovery area include: archived redo log files, control files, backups created by Recovery Manager (RMAN), flashback logs, and the change tracking file.


By allocating a storage location and unifying related recovery files within a specific area, the Oracle database server relieves the database administrator from having to manage the disk files created by these components.Follow the steps below to verify that your database is in ARCHIVELOG mode and configure the flash recovery area.

Log in to Enterprise Manager Database Console by opening your browser and entering the following URL:
http://localhost:1158/em

Enter sys/oracle as SYSDBA and click Login.



The Oracle Database Home page allows you to view the current state of the database by displaying a series of metrics that portray the overall health of the database. The Oracle Database Home page provides a launch point for the database status and administration and configuration of the database environment. It contains four pages via subtabs with each page displaying subsections. Click on the Maintenance tab.



Under Backup/Recovery Settings, click Recovery Settings.

You need to put the database in archivelog mode. In the Media Recovery section, select the ARCHIVELOG Mode check box. Then scroll down to the Flash Recovery Area section.

Scroll down to the Flash Recovery Area region of the page and click Enable Flashback Database. Change the Flashback Retention Time to 6 hours, and then click Apply.

Click Yes to restart the database.

Enter your Host Credentials as oracle/ and Database Credentials as sys/ as SYSDBA. Check the box to Save as Preferred Credentials and then click OK.

Click Yes to confirm.

Your database is being restarted. Wait about 10 minutes and click Refresh.

Once you click Refresh, the DB Control Home Page appears and you are automatically logged in as the SYS user.