Book Image

Oracle Data Guard 11gR2 Administration : Beginner's Guide

Book Image

Oracle Data Guard 11gR2 Administration : Beginner's Guide

Overview of this book

Data Guard is the high availability, disaster recovery and data replication solution for Oracle Databases. With the huge growth of Data Guard it's getting harder to encounter an Oracle DBA not dealing with Data Guard. Since it's a common DBA task to provide high availability of databases, Data Guard is a must-know topic for every Oracle Database Administrator."Oracle Data Guard 11g R2 Beginner's Administration Guide" is a practical guide that provides all the information you will need to configure and maintain Data Guard. This book will show you what Data Guard can really do.By following the practical examples in this book, you'll learn to set up your Data Guard Broker, the management framework for Data Guard configurations. Learn and implement different data protection modes, perform role transitions between databases (switchover and failover) and configure Active Data Guard. Next, we will dive into the features of Snapshot Standby. The book progresses into looking at Data Guard configuration with other Oracle products (such as EM, RAC, and RMAN) and patch databases in Data Guard. The final chapters will cover commonly encountered Data Guard issues and Data Guard best practices, which are very important to make a Data Guard configuration perfect and take maximum advantage of Data Guard properties.
Table of Contents (19 chapters)
Oracle Data Guard 11gR2 Administration Beginner's Guide
Credits
About the Authors
About the Reviewers
www.PacktPub.com
Preface
Pop Quiz Answers
Index

Using flashback on a standby database


Flashback is a useful feature introduced in Oracle database version 9i and more properties were added on in the next versions, 10g and 11g. When enabled, the flashback feature helps us recover data loss, corrupted data, or logical errors easily. In the following scenarios, we can use flashback with PITR (Point-in-Time Recovery) to recover data:

  • Dropped tables

  • Truncated tables

  • Massive changes by inserts / updates / deletes

  • Logical errors

If we're not using flashback, the steps to restore a table loss will be as follows:

  1. Restore the full database on a separate server using a backup performed before the table's drop operation.

  2. After restoring the database, perform the until time recovery.

  3. Open the database with resetlogs.

  4. Export the table from the restored database and import it into the production database.

If you are using flashback, you can use it to recover the table. However, if there is no standby database, this will be a disadvantage because we'll need to...