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

The archived log deletion policy on the standby database


The continuously transferred redo transaction is archived at the standby database before or after being applied, depending on the configuration. At the end, we're faced with lots of files filling the log destination either on the filesystem or ASM disk group. We need to build an automatic structure on the standby site, where applied archived logs are deleted automatically based on a specific logic.

There are several methods for archived log deletion. It's possible to delete archived logs with the rm command of the operation system or ASM. However, if we use rm, the control file will not be updated about the deletion of archived logfiles. Thus, in order to update the control file with the deletion operation, we must run crosscheck and delete expired RMAN commands as follows:

RMAN> crosscheck archivelog all; 
RMAN> delete expired archivelog all;

Another option is scheduling an RMAN job that deletes applied archived logs on the standby...