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

Time for action – fixing NOLOGGING changes on a standby database with incremental datafile backups


As a prerequisite for this exercise, first put the primary database in the no-force logging mode using the ALTER DATABASE NO FORCE LOGGING statement. Then perform some DML operations in the primary database using the NOLOGGING clause so that we can fix the issue in the standby database with the following steps:

  1. Run the following query to identify the datafiles that are affected by NOLOGGING changes:

    SQL> SELECT FILE#, FIRST_NONLOGGED_SCN FROM V$DATAFILE WHERE FIRST_NONLOGGED_SCN > 0;
    
    FILE#      FIRST_NONLOGGED_SCN
    ---------- -------------------
             4            20606544
    
  2. First we need to put the affected datafiles in the OFFLINE state in the standby database. For this purpose, stop Redo Apply in the standby database, execute the ALTER DATABASE DATAFILE ... OFFLINE statement, and start Redo Apply again:

    SQL> ALTER DATABASE RECOVER MANAGED STANDBY DATABASE CANCEL;
    SQL> ALTER DATABASE...