Preface

Oracle Data Guard is the most effective solution available today to pro tect the core asset of any enterprise--its data, and make it available on a 24x7 basis even in the face of disasters and other calami ties.

This guide describes Oracle Data Guard technology and concepts, and helps you configur e and implement standby databases.

This preface contains the following topics:

Audience
< a name="972765">Documentation Accessibility
Organization
Re lated Documentation
Conventions

Audience

Oracle Data Guard Concepts and Administration is intended for database administrators (DBAs) who adminis ter the backup, restoration, and recovery operations of an Oracle database system.

To use th is document, you should be familiar with relational database concepts and basic backup and recovery administration. You should also b e familiar with the operating system environment under which you are running Oracle software.

Documentation Accessibility

Our goal is to make Oracle products, services, and supporting documentation accessible, with good usability, to the disabled community. To that end, our documentation includes features that make information available to users of assistive technology. This documentation is avai lable in HTML format, and contains markup to facilitate access by the disabled community. Standards will continue to evolve over time , and Oracle is actively engaged with other market-leading technology vendors to address technical obstacles so that our documentatio n can be accessible to all of our customers. For additional information, visit the Oracle Accessibility Program Web site at

http://www.oracle.com/accessibility/< /p>

Accessibility of Code Examples in Documentation< /font>

JAWS, a Windows screen reader, may not always correctly read the code examples in th is document. The conventions for writing code require that closing braces should appear on an otherwise empty line; however, JAWS may not always read a line of text that consists solely of a bracket or brace.

Organization

This document contains:

Part I, "Concepts and Administration"

Chapter 1, "Introduction to O racle Data Guard"

This chapter offers a general overview of the Oracle Data Guar d architecture.

Chap ter 2, "Getting Started with Data Guard"

This chapter describes physical an d logical databases in more detail and the various interfaces you can use to manage the Data Guard configuration. It also describes t he operational requirements for using Data Guard and provides recommendations for setting up directory structures on standby database s.

Chapter 3, "Creating a Physical Standby Database"

This chapter explains how to create a ph ysical standby database.

Chapter 4, "Creating a Logical Standby Database"

This chapter explai ns how to create a logical standby database.

Chapter 5, "Log Transport Services"

This c hapter introduces log transport services. It describes the data protection modes that protect the production database against loss in the event of an unplanned outage, and it provides procedures and guidelines for configuring log transport services on a primary and standby database.

Chapter 6, "Log Apply Services"

This chapter introduces log apply service s. It provides guidelines for managing log apply services for physical and logical standby databases.

Chapter 7, "Role Management"< /a>

This chapter introduces role management services. It provides information about databas e failover and switchover role transitions.

Chapter 8, "Managing a Physical Standby Database"

This chapter describes how to manage a physical standby database. It provides information about monitoring and responding to event s that affect a standby database.

Chapter 9, "Managing a Logical Standby Database"

This cha pter describes how to manage a logical standby database. It provides information about managing SQL Apply, system tuning, and tablesp ace management.

Chapter 10, "Data Guard Scenarios"

This chapter describes common database s cenarios such as creating, recovering, failing over, switching over, configuring, and backing up standby and primary databases.

< a name="970606">

Part II, "Reference"

Chapter 11, "Initialization Pa rameters"

This reference chapter describes initialization parameters for each Or acle instance, including the primary database and each standby database in the Data Guard environment.

Chapter 12, "LOG_ARCHIVE_DEST_n Parameter Attributes"

This reference chapter provides syntax and examples for th e attributes of the LOG_ARCHIVE_DEST_n initialization parameter.

Chapter 13, "SQL Statements Relevant to Data Guard"

This reference chapter provides SQL statements that are useful for performing operations on a Data Guard configuration.

Chapter 14, "Views Relevant to Oracle Data Guard"

This reference chapte r lists views that contain useful information for monitoring the Data Guard environment. It summarizes the columns contained in each view and provides a description for each column.

Part III, "Appendixes and Glossary"

Appendix A, "Troubleshooting Data Guard"

This appendix discusses troubleshooting tips for Data Guard and standby databases.

Appendix B, "Data Guard and Real Application Clusters"< /font>

This appendix describes the primary and standby database configurations in a Rea l Application Clusters environment.

Appendix C, "Cascaded Redo Log Destinations"

This app endix describes how to implement cascaded redo log file destinations, whereby a standby database receives redo data from another stan dby database, instead of directly from the primary database.

Appendix D, "Creating a Physical Standby Database with Recovery Manager"
This appendix describes how to use Recovery Manager to create a physical standby database.

Appendix E, "Sett ing Archive Tracing"

This appendix describes how the LOG_ARCHIVE_TRACE parameter controls output generated by the ARCn, LGWR, and foreground processes on the primary database , and the RFS and FAL server processes on the standby database.


 
Appendix F, "Sample Disaster Recovery ReadMe File"
 
This appendix provides a sample ReadMe file that includes the kind of information that the person who is m
aking disaster recovery decisions would need when deciding which standby database should be the target of the failover operation.

 
Related Documentation
<
/a> 
Readers of Oracle Data Guard Concepts and Administration should also read:

The beginning of Oracle Database Concepts, that provides an overview of the concepts and terminology related to the Or
acle database and serves as a foundation for the more detailed information in this guide.
The chapters in the Oracle Database Ad
ministrator's Guide that deal with managing the control files, online redo log files, and archived redo log files.
The chapter in the Oracle Database Utilities that discusses LogMiner technology.
Oracle Data Guard Broker that des
cribes the graphical user interface and command-line interface for automating and centralizing the creation, maintenance, and monitor
ing of Data Guard configurations.
 
Discussions in this book also refer you to the follo
wing guides:

Oracle Database SQL Reference
Oracle Database Reference
Oracle Database
 Backup and Recovery Basics
Oracle Database Backup and Recovery Advanced User's Guide
Oracle Net Service
s Administrator's Guide
SQL*Plus User's Guide and Reference

Oracle High Availability Architecture and Bes
t Practices
 
If you need to upgrade existing Data Guard configurations to this
 Oracle release, see Oracle Database Upgrade Guid
e for complete instructions. In addition, refer to Oracle Database Concepts for information about other Oracle products and features that provide disaster recovery
and high-availability solutions.
 
Also, see Oracle Streams Concepts and Administration for information about Oracle Streams and the S
treams Downstream Capture Database. The Streams downstream capture process uses the Oracle Data Guard log transport services to trans
fer redo data to log files on a remote database where a Streams capture process captures changes in the archived redo log files at th
e remote destination.
 
Printed documentation is available for sale in the Oracle Store at

http://oraclestore.oracle.com/




To download free release notes, installation documentation, white papers, or other col
lateral, please visit the Oracle Technology Network (OTN). You must register online before using OTN; registration is free and can be
 done at
http://otn.oracle.com/membership/
<
a name="972334">



If you already have a username and password for OTN, then you can go
 directly to the documentation section of the OTN Web site at
http://otn.oracle.com/documentation/



Conventions
 
This section describes the conventions used in the text and
code examples of this document. The following table describes those conventions and provides examples of their use.
 

<
td class="Informal">lowercase monospace (fixed-width font) italic



 Convention
 Meanin
g
 Example


 
[ ]
 
Brackets enclos
e one or more optional items. Do not enter the brackets.
 
DEC
IMAL (digits [ , precision ])

 
{ }
 
Braces enclose two or more items, one of which is required. Do not enter the braces.
 
{ENABLE | DISABLE}

 
|
 
A vertical bar represents a choice of two or more options within brackets or braces. Enter one of the options. Do not enter the
 vertical bar.
 
{ENABLE | DISABLE} 

[COMPRESS | NOCOMPRESS]

 
...
 
Hori
zontal ellipsis points indicate either:

That we have omitted pa
rts of the code that are not directly related to the example
That you can repea
t a portion of the code
 

CREATE TABLE ... AS subquery; 

SELECT col1, col2, ... , coln FROM employees;

 
. 
. 
.<
/p>
 
Vertical ellipsis points indicate that we have omitted several lin
es of code not directly related to the example.
 

 
Bold
 
Bold typeface indicates terms that are defined in the text or terms that ap
pear in a glossary, or both.
 
When you specify this clause, you cre
ate an index-organized table.

 
UPPERCASE monospace (fixed-width font)
 
Uppercase monospace typeface indicates elements supplied by the system.
 
You can back up the database by using the BACKUP command. 
Use the DBMS_STATS.GENERATE_STATS procedure.

 
lowercase monospace (fixed-width font)
 
Lowercase monospace typeface indicates executables, filenames, directory
 names, and sample user-supplied elements.
 
Enter sqlplus to open SQL*Plus. 

Back up the datafiles and control files in the /disk1/oracle/dbs<
/code> directory. 

The department_id, department_name, and loc
ation_id columns are in the hr.departments table.
 


 
Lowercase monospace italic font represents placeholders or variables.<
/td>
 
You can specify the parallel_clause. 
Run Uold_release.SQL where old_release<
/em> refers to the release you installed prior to upgrading.

 
MixedCase

monospace (fixed-width font)
 
Mixed-case monospace typeface indicates a Data Guard broker database property. The mixed case h
elps you visually differentiate a Data Guard broker property from other system-supplied elements, which are always shown in uppercase
 typeface. 
Mixed-case monospace typeface can also indicate other programmatic elements. Enter
 these elements as shown.
 
The StandbyFileManagement p
roperty corresponds to the STANDBY_FILE_MANAGEMENT initialization parameter. 
The
 JRepUtil class implements these methods.

Convention	Meanin g	Example
[ ]	Brackets enclos e one or more optional items. Do not enter the brackets.	`DEC IMAL (``digits` `[ ,` `precision` `])`
{ }	Braces enclose two or more items, one of which is required. Do not enter the braces.	`{ENABLE \| DISABLE}`
\|	A vertical bar represents a choice of two or more options within brackets or braces. Enter one of the options. Do not enter the vertical bar.	`{ENABLE \| DISABLE}` `[COMPRESS \| NOCOMPRESS]`
`...`	Hori zontal ellipsis points indicate either: That we have omitted pa rts of the code that are not directly related to the example That you can repea t a portion of the code	`CREATE TABLE ... AS` `subquery``;` `SELECT` `col1``,` `col2``, ... , coln FROM employees;`
. . .< /p>	Vertical ellipsis points indicate that we have omitted several lin es of code not directly related to the example.
Bold	Bold typeface indicates terms that are defined in the text or terms that ap pear in a glossary, or both.	When you specify this clause, you cre ate an index-organized table.
`UPPERCASE monospace (fixed-width font)`	Uppercase monospace typeface indicates elements supplied by the system.	You can back up the database by using the `BACKUP` command. Use the `DBMS_STATS`.`GENERATE_STATS` procedure.
`lowercase monospace (fixed-width font)`	Lowercase monospace typeface indicates executables, filenames, directory names, and sample user-supplied elements.	Enter `sqlplus to open SQL*Plus.` `Back up the datafiles and control files in the /disk1/oracle/dbs< /code> directory. The department_id, department_name, and loc ation_id columns are in the hr.departments table.`
Lowercase monospace italic font represents placeholders or variables. < /td>	You can specify the `parallel_clause`. Run `U``old_release``.SQL` where `old_release`< /em> refers to the release you installed prior to upgrading.
`MixedCase monospace (fixed-width font)`	Mixed-case monospace typeface indicates a Data Guard broker database property. The mixed case h elps you visually differentiate a Data Guard broker property from other system-supplied elements, which are always shown in uppercase typeface. Mixed-case monospace typeface can also indicate other programmatic elements. Enter these elements as shown.	The `StandbyFileManagement` p roperty corresponds to the `STANDBY_FILE_MANAGEMENT` initialization parameter. The `JRepUtil` class implements these methods.