This guide for using Dataguard technology covers all areas of disaster recovery, standby databases, and automatic Oracle failover. The details of how Oracle10g's improved Dataguard provides a comprehensive solution for disaster recovery while keeping a low TCO are discussed. Descriptions of the concepts and architecture of standby databases as well as the implementation and management of Dataguard are provided. Tips for success in configuration and first-time implementation of Dataguard including the internal working of Dataguard Broker and Dataguard with Recovery Manager are revealed.
| Using the Online Code Depot | 1 | |
| Conventions Used in this Book | 3 | |
| Structure of the Book | 5 | |
| Acknowledgements | 8 | |
| Preface | 9 | |
| Chapter 1 | Introduction to Oracle Data Guard | 11 |
| Introduction | 11 | |
| Oracle Failover Options | 13 | |
| Failover and Oracle licensing | 15 | |
| Manual standby database | 16 | |
| Standby Database Concepts | 18 | |
| History of the Standby Database | 20 | |
| Chronological Development of Standby Technology | 21 | |
| Types of Standby Databases | 23 | |
| Physical Standby Database | 24 | |
| Logical Standby Database | 26 | |
| Archive Log Repository | 27 | |
| Benefits and Drawbacks of Data Guard | 28 | |
| Disaster Protection | 28 | |
| Load Balancing | 29 | |
| Automated Management | 30 | |
| Data Guard is not a Cheap Option | 30 | |
| Data Guard Operational Constraints | 31 | |
| Lifecycle of a Standby Database | 31 | |
| Creation of Standby Database | 32 | |
| Recovery or read-only mode | 33 | |
| Switchover or failover operation | 33 | |
| A Sample Data Guard Configuration | 34 | |
| Conclusion | 36 | |
| Chapter 2 | Data Guard Architecture | 38 |
| Introduction | 38 | |
| Architectural Components | 40 | |
| Process Architecture | 40 | |
| Redo Log File | 43 | |
| Archived Redo Log File | 44 | |
| Data Guard Apply Modes | 44 | |
| Redo Apply Mode | 45 | |
| SQL Apply Mode | 45 | |
| Understanding Log Miner Technology | 46 | |
| Archive Gap Sequence | 48 | |
| Detection and Resolution | 49 | |
| Data Guard Broker Architecture | 50 | |
| Configuration, Sites and Resources | 52 | |
| Server Side Components of the Broker | 54 | |
| Client Side Components of the Broker | 55 | |
| Role of the Transport Network Substrate | 56 | |
| Conclusion | 57 | |
| Chapter 3 | Implementing Standby Databases | 58 |
| Introduction | 58 | |
| Physical Standby Database | 59 | |
| Manual Recovery - Physical Standby Database | 59 | |
| Managed Recovery - Physical Standby Database | 60 | |
| Read-Only - Physical Standby Database | 60 | |
| Creating a Physical Standby Database | 61 | |
| On the Remote Host Machine | 62 | |
| On a Local Host Machine | 82 | |
| Accommodating the Difference in Directory Structure between the Primary and Standby Sites | 86 | |
| Creating a Logical Standby Database | 87 | |
| Limitations of the Logical Standby Database | 88 | |
| Requirements for the Logical Standby Database | 90 | |
| Creating a Logical Standby Database | 95 | |
| Sample Configuration | 113 | |
| Conclusion | 117 | |
| Chapter 4 | Standby Database Administration | 119 |
| Introduction | 119 | |
| Administration of Physical Standby Databases | 120 | |
| General Administration Tasks | 120 | |
| Monitor Physical Standby Databases | 127 | |
| Propagating Unrecoverable Operations to Standby Databases | 132 | |
| Physical Standby Databases with Time Lag | 136 | |
| Resolving Archive Gap Sequence on Physical Standby Databases | 137 | |
| Administration of Logical Standby Databases | 139 | |
| Starting Up and Shutting Down Logical Standby Databases | 140 | |
| Starting and Stopping the Log Apply Service | 140 | |
| Monitoring Logical Standby Databases | 141 | |
| Managing Schema Objects | 146 | |
| Logical Standby Databases with Time Lag | 152 | |
| Resolving Archive Gap Sequence on Logical Standby Databases | 153 | |
| Cascaded Standby Databases | 154 | |
| Using Physical Standby Databases for Cascaded Standby Databases | 156 | |
| Using Logical Standby Databases for Cascaded Standby Databases | 158 | |
| Conclusion | 159 | |
| Chapter 5 | Log Management Services | 160 |
| Introduction | 160 | |
| Log Transport Services | 161 | |
| Log Apply Services | 162 | |
| Physical Standby Database | 163 | |
| Logical Standby Database | 164 | |
| Log Management Policies | 165 | |
| Factors Influencing Log Transport Policies | 166 | |
| A Sample Log Management Policy | 170 | |
| Standby Redo Logs | 171 | |
| Description of remote_archive_enable Parameter | 174 | |
| Log Transport Service Transmission Attributes | 174 | |
| Process to Transfer Redo Data | 175 | |
| Network Characteristics Influencing Redo Transmission | 175 | |
| Acknowledging Redo Disk I/O Operation on the Standby Database | 177 | |
| Standby Database Protection Modes | 179 | |
| Protection Modes in Oracle9i Release 1 | 180 | |
| Protection Modes in Oracle9i Release 2 | 182 | |
| Conclusion | 186 | |
| Chapter 6 | Switchover and Failover | 188 |
| Introduction | 188 | |
| Types of Database Role Transitions | 191 | |
| Role Transition Using Switchover | 191 | |
| Role Transition Using Failover | 192 | |
| Determining a Suitable Standby Database for Role Transition | 193 | |
| Disadvantages of Transitioning to a Logical Standby Database | 194 | |
| Switchover Operation | 195 | |
| Preparing the Primary Database for Switchover | 195 | |
| Preparing the Standby Database for Switchover | 196 | |
| Switchover to a Physical Standby Database | 198 | |
| Switchover to a Logical Standby Database | 200 | |
| Verify Switchover Operation | 201 | |
| Failover Operation | 202 | |
| Failover to a Physical Standby Database | 202 | |
| Failover to a Logical Standby Database | 205 | |
| Verify Failover Operation | 206 | |
| Impact on Other Standby Database in Configuration | 207 | |
| Transparent Application Failover | 207 | |
| Conclusion | 208 | |
| Chapter 7 | Performance Tuning of Data Guard Configuration | 211 |
| Introduction | 211 | |
| Understanding Tuning Requirements | 212 | |
| Monitoring Data Guard Performance | 213 | |
| Tuning the Log Transfer Service | 215 | |
| Gathering Log Transfer Related Statistics | 215 | |
| Determining Optimal Network Bandwidth | 217 | |
| Gathering Oracle Net Related Statistics | 220 | |
| Network Tuning for the Log Transport Service | 221 | |
| I/O Activity on the Standby Host | 223 | |
| Tuning the Data Guard Log Apply Services | 224 | |
| Gathering Log Apply Service Related Statistics | 224 | |
| Physical Standby Database | 224 | |
| Logical Standby Database | 226 | |
| Statistics Related to Log Mining Engine and Memory Usage | 227 | |
| Tuning Tips for the SQL Apply Operation | 229 | |
| Configuring Data Guard for High Performance | 231 | |
| Conclusion | 232 | |
| Chapter 8 | Data Guard Broker | 234 |
| Introduction to Data Guard broker | 234 | |
| Broker Concept | 235 | |
| Broker Management Model in Oracle10g | 236 | |
| States and Properties | 237 | |
| Preparing to Use Data Guard Broker | 238 | |
| Managing Data Guard Using DGMGRL | 239 | |
| Data Guard Configuration Management | 240 | |
| Viewing Configuration and Site Attributes | 242 | |
| Administration of Log Management Services | 245 | |
| Role Transition using Data Guard Broker | 247 | |
| Managing Data Protection Modes | 249 | |
| Conclusion | 251 | |
| Chapter 9 | Recovery Manager and Data Guard | 253 |
| Introduction | 253 | |
| Explanation of RMAN Terminology | 255 | |
| Creating Physical Standby Databases using RMAN | 258 | |
| What needs to be Backed Up for a Standby Database Creation? | 258 | |
| Creation Using a Backup Set | 259 | |
| Creation Using Image Copies | 266 | |
| Backup of a Standby Database Using RMAN | 268 | |
| Conclusion | 270 | |
| Chapter 10 | Oracle 10g: New Features of Data Guard | 271 |
| Introduction | 271 | |
| Oracle10g Data Guard Enhancements | 272 | |
| Overview of Oracle 10g New Data Guard Features | 273 | |
| 10g Data Guard Supplemental Loggin | 280 | |
| Upgrading to Oracle10g Data Guard | 281 | |
| Architectural Changes | 282 | |
| Standby Redo Logs | 282 | |
| Flashback Database | 284 | |
| Creating Standby Databases Using Oracle10g | 285 | |
| Enhanced Data Type Support | 285 | |
| Creating Logical Standby Databases | 286 | |
| Improvements in Data Guard Management | 289 | |
| Administration of Standby Database | 289 | |
| Improved Log Management Services | 290 | |
| Data Guard Performance Improvement | 293 | |
| Conclusion | 295 | |
| Book Conclusion | 296 | |
| Appendix A | Data Guard Reference | 297 |
| Data Guard Reference | 297 | |
| Initialization Parameters | 298 | |
| The db_file_name_convert parameter | 298 | |
| The fal_client parameter | 298 | |
| The fal_server parameter | 299 | |
| The log_archive_dest_n parameter | 299 | |
| The db_unique_name parameter | 307 | |
| The log_archive_dest_state_n parameter | 308 | |
| The log_file_name_convert parameter | 309 | |
| The remote_archive_enable parameter | 309 | |
| The standby_archive_dest parameter | 309 | |
| The standby_file_management parameter | 309 | |
| Dynamic Performance Views | 310 | |
| Common Views | 310 | |
| Physical Database Only Views | 319 | |
| Logical Database Only Views | 320 | |
| PL/SQL Supplied Packages for Data Guard | 326 | |
| dbms_logstdby Supplied Package | 326 | |
| Appendix B | Troubleshooting Guide | 331 |
| B.1 | Resolving Issues Related to Log Transport Services | 331 |
| B.2 | SQL Apply Operation on the Logical Standby Database Stalls Due to Lack of Space in the Tablespace for LogMiner Dictionary | 333 |
| B.3 | Log Apply Service Stops Due to Missing Temp files | 335 |
| B.4 | Upgrading the Protection Mode Causes the Primary Database to Shutdown | 336 |
| B.5 | Error When Recovering from Partial Archived Redo Log File | 337 |
| Index | 339 | |
| About the Author | 344 | |
| About Mike Reed | 345 |
Overview
This guide for using Dataguard technology covers all areas of disaster recovery, standby databases, and automatic Oracle failover. The details of how Oracle10g's improved Dataguard provides a comprehensive solution for disaster recovery while keeping a low TCO are discussed. Descriptions of the concepts and architecture of standby databases as well as the implementation and management of Dataguard are provided. Tips for success in configuration and first-time implementation of Dataguard including the internal ...