Preface
Data Guard is the Oracle technology that meets high availability, disaster recovery, and data protection requirements for the Oracle Database, and is the market leader product for this scope. In enterprise systems, Data Guard is very widely used, so managing Data Guard configurations is a common task of Oracle DBAs. This administration task is not just about installing and keeping standby databases synchronized with the primary database. DBAs also provide standby databases for reporting and testing purposes, recovering partial data by using them, performing role transitions for disaster recovery testing or for planned maintenance operations, integrating Data Guard with the existing Oracle environment, and so on. As an Oracle DBA, you need to learn how to install and maintain Data Guard and benefit from it as much as possible.
In this practical book, you'll not only be introduced to Oracle Data Guard, you'll also see all aspects of Data Guard administration with examples, recipes, and best practices. We'll start by learning about the fundamental components of Data Guard, and then continue with configuring physical and logical standby databases of Data Guard. The important details and best practices of Data Guard administration will be covered later on.
What this book covers
Chapter 1, Getting Started, includes an introduction to Oracle Data Guard. Configuration elements, the architecture of the physical and logical standby databases, Data Guard services, the history of Data Guard, and a comparison with other replication solutions are covered in this chapter.
Chapter 2, Configuring the Oracle Data Guard Physical Standby Database, explains how to prepare the configuration from scratch, create a physical standby database including post tasks with a step-by-step approach, and verify the physical standby database recovery including real-time apply.
Chapter 3, Configuring Oracle Data Guard Logical Standby Database, shows you how to prepare a logical standby database configuration with pre and post steps. Customization and management in a logical standby database are also covered.
Chapter 4, Oracle Data Guard Broker, explains the detailed implementation of the Data Guard broker, monitoring and managing Data Guard using the broker, troubleshooting the Data Guard broker, and configuring fast-start failover (FSFO).
Chapter 5, Data Guard Protection Modes, focuses on the three data protection modes of Oracle Data Guard. You'll learn how to choose the correct mode for your requirements and how to change modes using SQL*Plus, the Data Guard broker, and Enterprise Manager Cloud Control.
Chapter 6, Data Guard Role Transitions, will include the necessary steps to accomplish successful switchover and failover operations in the physical and logical standby database environments. It also covers different tools to perform role transitions.
Chapter 7, Active Data Guard, Snapshot Standby, and Advanced Techniques, explains what Active Data Guard is, how to integrate applications with Active Data Guard, and several advantages of using it, such as performing Data Pump exports, gathering ASH reports, and advanced compression. This chapter also describes how to use snapshot standby, implement cascade standby databases, configure the cross-platform Data Guard setup, and also provides a brief on Data Guard tuning.
Chapter 8, Integrating Data Guard with the Complete Oracle Environment, explains the configuration steps required to integrate Data Guard with Enterprise Manager Grid Control, RMAN, and RAC. Integrating Data Guard with these products is crucial to make an efficient configuration and take advantage of all of these products together.
Chapter 9, Data Guard Configuration Patching, explains how to apply one-off patches and patch set updates to databases in a Data Guard environment, and some best practices of patching.
Chapter 10, Common Data Guard Issues, gives practical information for dealing with some very common issues in Data Guard that every administrator needs to know and experience.
Chapter 11, Data Guard Best Practices, includes very important information regarding how to make a Data Guard configuration perfect and take maximum advantage of Data Guard properties. Connection failover, deletion of archived log files, using flashback, database rolling upgrade using transient logical standby and corruption detection, and prevention and automatic repair with Oracle Data Guard are covered.
What you need for this book
In order to follow the exercises in this book, you must install the Oracle Database 11g Release 2 software on two separate database servers (primary and standby). You can use a virtual machine to create virtual database servers on your PC. Also, a database has to be created on the primary database server. The Oracle management software, Enterprise Manager 12c Cloud Control, needs to be installed to follow specific exercises using this tool.
Who this book is for
If you are an Oracle DBA who wants to configure and administer Data Guard and improve your knowledge on Data Guard with a step-by-step approach and hands-on scenarios, this book is for you. With a basic understanding of Oracle database administration you'll easily be able to follow the book.
Conventions
In this book, you will find several headings appearing frequently.
To give clear instructions of how to complete a procedure or task, we use:
Time for action – heading
- Action 1
- Action 2
- Action 3
Instructions often need some extra explanation so that they make sense, so they are followed with:
What just happened?
This heading explains the working of tasks or instructions that you have just completed.
You will also find some other learning aids in the book, including:
Pop quiz – heading
These are short multiple-choice questions intended to help you test your own understanding.
Have a go hero – heading
These are practical challenges that give you ideas for experimenting with what you have learned.
You will also find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.
Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: The LOG_ARCHIVE_DEST_n parameters must be configured properly on every instance of primary and standby databases to show remote archiving destinations.
A block of code is set as follows:
LOG_ARCHIVE_CONFIG =
{
[ SEND | NOSEND ]
[ RECEIVE | NORECEIVE ]
[ DG_CONFIG=(remote_db_unique_name1, ... remote_db_unique_name9) | NODG_CONFIG ]
When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:
2 DBMS_SCHEDULER.CREATE_JOB (
3 JOB_NAME => 'REFRESH_EMPDEPT_MV_PRIMARY',
4 JOB_TYPE => 'PLSQL_BLOCK',
Any command-line input or output is written as follows:
RFS LogMiner: Registered logfile [/u01/app/oracle/archive_std/1_106_791552282.arc] to LogMiner session id [1] ... LOGMINER: Begin mining logfile for session 1 thread 1 sequence 106, /u01/app/oracle/archive_std/1_106_791552282.arc LOGMINER: End mining logfile for session 1 thread 1 sequence 106, /u01/app/oracle/archive_std/1_106_791552282.arc
New terms and important words are shown in bold. Words that you see on the screen, in menus or dialog boxes for example, appear in the text like this: Expand the Data Guard Performance category and click on the Estimated Failover Time section.
Note
Warnings or important notes appear in a box like this.
Tip
Tips and tricks appear like this.
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