Contents

Title and Copyright Information

List of Examples

List of Figures

List of Tables

Send Us Your Comments

Preface

Documentation Accessibility

Related Documentation

What's New in Oracle Data Guard?

Part I Concepts and Administration

1 Introduction to Oracle Data Guard

1.1 Data Guard Configurations

1.1.1 Primary Database

1.1.2 Standby Databases

1.1.3 Configuration Example

1.2 Data Guard Services

1.2.1 Log Transport Services

1.2.2 Log Apply Services

1.2.3 Role Management Services

1.3 Data Guard Broker

1.3.1 Using Oracle Enterprise Manager

1.3.2 Using the Data Guard Command-Line Interface

1.4 Data Guard Protection Modes

1.5 Data Guard and Complementary Technologies

1.6 Summary of Data Guard Benefits

2 Getting Started with Data Guard

2.1 Standby Database Types

2.1.1 Physical Standby Databases

2.1.2 Logical Standby Databases

2.2 User Interfaces for Administering Data Guard Configurations

2.3 Data Guard Operational Prerequisites

2.3.1 Hardware and Operating System Requirements

2.3.2 Oracle Software Requirements

2.4 Standby Database Directory Structure Considerations

2.5 Online Redo Logs, Archived Redo Logs, and Standby Redo Logs

2.5.1 Online Redo Logs and Archived Redo Logs

2.5.2 Standby Redo Logs

3 Creating a Physical Standby Database

3.1 Preparing the Primary Database for Standby Database Creation

3.1.1 Enable Forced Logging

3.1.2 Create a Password File

3.1.3 Setting Primary Database Initialization Parameters

3.1.4 Enable Archiving

3.2 Creating a Physical Standby Database

3.2.1 Create a Backup Copy of the Primary Database Datafiles

3.2.2 Create a Control File for the Standby Database

3.2.3 Prepare an Initialization Parameter File for the Standby Database

3.2.4 Copy Files from the Primary System to the Standby System

3.2.5 Set Up the Environment to Support the Standby Database

3.2.6 Start the Physical Standby Database

3.2.7 Verify the Physical Standby Database Is Performing Properly

3.3 Further Preparations

4 Creating a Logical Standby Database

4.1 Preparing for Logical Standby Database Creation

4.1.1 Determine Support for Datatypes and Storage Attributes for Tables

4.1.2 Ensure Table Rows in the Primary Database Can Be Uniquely Identified

4.2 Creating a Logical Standby Database

4.2.1 Create a Physical Standby Database

4.2.2 Prepare the Primary Database to Support a Logical Standby Database

4.2.3 Prepare to Transition to a Logical Standby Database

4.2.4 Start the Logical Standby Database

4.2.5 Verify the Logical Standby Database Is Performing Properly

4.3 Further Preparations

5 Log Transport Services

5.1 Introduction to Log Transport Services

5.2 Where to Send Redo Data

5.2.1 Destination Types

5.2.2 Configuring Destinations with the LOG_ARCHIVE_DEST_n Parameter

5.2.3 Setting Up Flash Recovery Areas As Destinations

5.3 How to Send Redo Data

5.3.1 Using Archiver Processes (ARCn) to Archive Redo Data

5.3.2 Using the Log Writer Process (LGWR) to Archive Redo Data

5.3.3 Providing for Secure Redo Data Transmission

5.4 When Redo Data Should Be Sent

5.4.1 Specifying Role-Based Destinations with the VALID_FOR Attribute

5.4.2 Specify Unique Names for Primary and Standby Databases

5.5 What to Do If Errors Occur

5.6 Setting Up a Data Protection Mode

5.6.1 Choosing a Data Protection Mode

5.6.2 Configuring Standby Redo Log Files

5.6.3 Setting the Data Protection Mode of a Data Guard Configuration

5.7 Managing Log Files

5.7.1 Specifying Alternate Directory Locations for Archived Redo Log Files

5.7.2 Reusing Online Redo Log Files

5.7.3 Managing Standby Redo Log Files

5.7.4 Planning for Growth and Reuse of the Control Files

5.7.5 Sharing a Log File Destination Among Multiple Standby Databases

5.8 Managing Archive Gaps

5.8.1 When Is an Archive Gap Discovered?

5.8.2 How Is a Gap Resolved?

5.8.3 Using the Fetch Archive Log (FAL) Process to Resolve Archive Gaps

5.8.4 Manually Determining and Resolving Archive Gaps

5.9 Verification

5.9.1 Monitoring Log File Archival Information

5.9.2 Monitoring the Performance of Log Transport Services

6 Log Apply Services

6.1 Introduction to Log Apply Services

6.2 Log Apply Services Configuration Options

6.2.1 Using Real-Time Apply to Apply Redo Data Immediately

6.2.2 Specifying a Time Delay for the Application of Archived Redo Log Files

6.3 Applying Redo Data to Physical Standby Databases

6.3.1 Starting Redo Apply

6.3.2 Starting Real-Time Apply

6.3.3 Stopping Log Apply Services

6.3.4 Monitoring Log Apply Services on Physical Standby Databases

6.4 Applying Redo Data to Logical Standby Databases

6.4.1 Starting SQL Apply

6.4.2 Starting Real-time Apply

6.4.3 Stopping Log Apply Services on a Logical Standby Database

6.4.4 Monitoring Log Apply Services for Logical Standby Databases

6.5 Tuning the Log Apply Rate for a Physical Standby Database

7 Role Management

7.1 Introduction to Role Transitions

7.1.1 Which Role Transition to Use

7.1.2 Switchovers

7.1.3 Failovers

7.2 Role Transitions Involving Physical Standby Databases

7.2.1 Switchovers Involving a Physical Standby Database

7.2.2 Failovers Involving a Physical Standby Database

7.3 Role Transitions Involving Logical Standby Databases

7.3.1 Switchovers Involving a Logical Standby Database

7.3.2 Failovers Involving a Logical Standby Database

8 Managing a Physical Standby Database

8.1 Starting Up and Shutting Down a Physical Standby Database

8.1.1 Starting Up a Physical Standby Database

8.1.2 Shutting Down a Physical Standby Database

8.2 Using a Standby Database That Is Open for Read-Only Access

8.2.1 Assessing Whether or Not to Open a Standby Database for Read-Only Access

8.2.2 Opening a Physical Standby Database for Read-Only Access

8.2.3 Sorting Considerations for Standby Databases Open for Read-Only Access

8.3 Managing Primary Database Events That Affect the Standby Database

8.3.1 Adding a Datafile or Creating a Tablespace

8.3.2 Dropping a Tablespace in the Primary Database

8.3.3 Using Transportable Tablespaces with a Physical Standby Database

8.3.4 Renaming a Datafile in the Primary Database

8.3.5 Adding or Dropping Online Redo Log Files

8.3.6 Altering the Primary Database Control File

8.3.7 NOLOGGING or Unrecoverable Operations

8.4 Using RMAN to Back Up and Restore Files on a Physical Standby Database

8.4.1 Backup Procedure

8.4.2 Effect of Switchovers, Failovers, and Control File Creation on Backups

8.4.3 Additional Backup Situations

8.4.4 Deletion Policy for Archived Redo Log Files In Flash Recovery Areas

8.5 Recovering Through the OPEN RESETLOGS Statement

8.6 Monitoring the Primary and Standby Databases

8.6.1 Alert Log

8.6.2 Dynamic Performance Views (Fixed Views)

8.6.3 Monitoring Recovery Progress

9 Managing a Logical Standby Database

9.1 Configuring and Managing a Logical Standby Database

9.1.1 Managing SQL Apply

9.1.2 Controlling User Access to Tables in a Logical Standby Database

9.1.3 Deleting Archived Redo Log Files No Longer Needed By SQL Apply

9.1.4 Modifying a Logical Standby Database

9.1.5 How Triggers and Constraints Are Handled on a Logical Standby Database

9.1.6 Skipping SQL Statements on a Logical Standby Database

9.1.7 Adding or Re-creating Tables on a Logical Standby Database

9.1.8 Viewing and Controlling Logical Standby Events

9.1.9 Understanding and Viewing SQL Apply Activity

9.1.10 Enabling Real-Time Apply

9.1.11 Determining How Much Redo Data Was Applied

9.1.12 Recovering from Errors

9.1.13 Refreshing Materialized Views

9.2 Upgrading the Oracle Database Software Version

9.3 Recovering Through the OPEN RESETLOGS Statement

9.4 Tuning Logical Standby Databases

9.4.1 Create a Primary Key RELY Constraint

9.4.2 Gather Statistics for the Cost-Based Optimizer

9.4.3 Adjust the Transaction Consistency

9.4.4 Adjust the Maximum Number of Parallel Execution Processes

9.4.5 Control Memory Usage on the Logical Standby Database

10 Data Guard Scenarios

10.1 Setting Up and Verifying Archival Destinations

10.1.1 Configuring a Primary Database and a Physical Standby Database

10.1.2 Configuring a Primary Database and a Logical Standby Database

10.1.3 Configuring Both Physical and Logical Standby Databases

10.1.4 Verifying the Current VALID_FOR Attribute Settings for Each Destination

10.2 Choosing the Best Available Standby Database for a Role Transition

10.2.1 Example: Best Physical Standby Database for a Failover

10.2.2 Example: Best Logical Standby Database for a Failover Operation

10.3 Using Flashback Database After a Failover

10.3.1 Converting a Failed Primary Database into a Physical Standby Database

10.3.2 Converting a Failed Primary Database into a Logical Standby Database

10.4 Using Flashback Database After Issuing an Open Resetlogs Statement

10.4.1 Flashing Back a Physical Standby Database

10.4.2 Flashing Back a Logical Standby Database

10.5 Using a Physical Standby Database with a Time Lag

10.5.1 Establishing a Time Lag on a Physical Standby Database

10.5.2 Failing Over to a Physical Standby Database with a Time Lag

10.5.3 Switching Over to a Physical Standby Database with a Time Lag

10.6 Recovering from a Network Failure

10.7 Recovering After the NOLOGGING Clause Is Specified

10.7.1 Recovery Steps for Logical Standby Databases

10.7.2 Recovery Steps for Physical Standby Databases

10.7.3 Determining If a Backup Is Required After Unrecoverable Operations

10.8 Resolving Archive Gaps Manually

10.8.1 What Causes Archive Gaps?

10.8.2 Determining If an Archive Gap Exists

10.8.3 Manually Transmitting Log Files in the Archive Gap to the Standby Site

10.8.4 Manually Applying Log Files in the Archive Gap to the Standby Database

10.9 Creating a Standby Database That Uses OMF or ASM

Part II Reference

11 Initialization Parameters

12 LOG_ARCHIVE_DEST_n Parameter Attributes

13 SQL Statements Relevant to Data Guard

13.1 ALTER DATABASE Statements

13.2 ALTER SESSION Statements

14 Views Relevant to Oracle Data Guard

Part III Appendixes

A Troubleshooting Data Guard

A.1 Common Problems

A.1.1 Standby Archive Destination Is Not Defined Properly

A.1.2 Renaming Datafiles with the ALTER DATABASE Statement

A.1.3 Standby Database Does Not Receive Redo Data from the Primary Database

A.1.4 You Cannot Mount the Physical Standby Database

A.2 Log File Destination Failures

A.3 Handling Logical Standby Database Failures

A.4 Problems Switching Over to a Standby Database

A.4.1 Switchover Fails Because Redo Data Was Not Transmitted

A.4.2 Switchover Fails Because SQL Sessions Are Still Active

A.4.3 Switchover Fails Because User Sessions Are Still Active

A.4.4 Switchover Fails with the ORA-01102 Error

A.4.5 Switchover Fails Because Redo Data Is Not Applied After the Switchover

A.4.6 Roll Back After Unsuccessful Switchover and Start Over

A.5 What to Do If SQL Apply Stops

A.6 Network Tuning for Redo Data Transmission

A.7 Managing Data Guard Network Timeout

A.8 Slow Disk Performance on Standby Databases

A.9 Log Files Must Match to Avoid Primary Database Shutdown

B Data Guard and Real Application Clusters

B.1 Configuring Standby Databases in a Real Application Clusters Environment

B.1.1 Setting Up a Multi-Instance Primary with a Single-Instance Standby

B.1.2 Setting Up a Multi-Instance Primary with a Multi-Instance Standby

B.1.3 Setting Up a Cross-Instance Archival Database Environment

B.2 Configuration Considerations in a Real Application Clusters Environment

B.2.1 Format for Archived Redo Log Filenames

B.2.2 Archive Destination Quotas

B.2.3 Data Protection Modes

B.2.4 Role Transitions

B.3 Troubleshooting

B.3.1 Switchover Fails in a Real Application Clusters Configuration

B.3.2 Avoiding Downtime in Real Application Clusters During a Network Outage

C Cascaded Redo Log Destinations

C.1 Configuring Cascaded Redo Log Destinations

C.1.1 Configuring Cascaded Redo Log Destinations for Physical Standby Databases

C.1.2 Configuring Cascaded Redo Log Destinations for Logical Standby Databases

C.2 Role Transitions with Cascaded Redo Log Destinations

C.2.1 Standby Databases Receiving Redo Data from a Physical Standby Database

C.2.2 Standby Databases Receiving Redo Data from a Logical Standby Database

C.3 Examples of Cascaded Redo Log Destinations

C.3.1 Local Physical Standby and Cascaded Remote Physical Standby

C.3.2 Local Physical Standby and Cascaded Remote Logical Standby

C.3.3 Local and Remote Physical Standby and Cascaded Local Logical Standby

C.3.4 Consolidated Reporting with Cascaded Logical Standby Destinations

C.3.5 Temporary Use of Cascaded Destinations During Network Upgrades

D Creating a Physical Standby Database with Recovery Manager

D.1 Preparing to Use RMAN to Create a Standby Database

D.1.1 About Standby Database Preparation Using RMAN

D.1.2 Creating the Standby Control File with RMAN

D.1.3 Naming the Standby Database Datafiles When Using RMAN

D.1.4 Naming the Standby Database Log Files When Using RMAN

D.2 Creating a Standby Database with RMAN: Overview

D.2.1 RMAN Standby Creation Without Recovery

D.2.2 RMAN Standby Creation with Recovery

D.3 Setting Up the Standby Instance

D.4 Creating a Standby Database with the Same Directory Structure

D.4.1 Creating the Standby Database Without Performing Recovery

D.4.2 Creating the Standby Database and Performing Recovery

D.5 Creating a Standby Database with a Different Directory Structure

D.5.1 Naming Standby Database Files with DB_FILE_NAME_CONVERT

D.5.2 Naming Standby Database Files with SET NEWNAME

D.5.3 Naming Standby Database Files with CONFIGURE AUXNAME

D.6 Creating a Standby Database on the Local Host

D.7 Creating a Standby Database with Image Copies

D.7.2 When Copies and Datafiles Use the Same Names

D.7.3 When Copies and Datafiles Use Different Names

D.8 Usage Scenario

E Setting Archive Tracing

E.1 LOG_ARCHIVE_TRACE Initialization Parameter

E.2 Determining the Location of the Trace Files

E.2.1 Setting the LOG_ARCHIVE_TRACE Initialization Parameter

E.2.2 Choosing an Integer Value

F Sample Disaster Recovery ReadMe File

Index