Book Image

Oracle Database 12c Backup and Recovery Survival Guide

Book Image

Oracle Database 12c Backup and Recovery Survival Guide

Overview of this book

The three main responsibilities of a successful DBA are to ensure the availability, recoverability, and performance of any database. To ensure the recoverability of any database, a DBA needs to have a strong backup and recovery skills set. Every DBA is always looking for a reference book that will help them to solve any possible backup and recovery situation that they can come across in their professional life. Oracle Database 12c Backup and Recovery Survival Guide has the unique advantage to be a reference to all Oracle backup and recovery options available, making it essential for any DBA in the world. If you are new to Oracle Database, this book will introduce you to the fantastic world of backup and recovery that is vital to your success. If you are an experienced DBA, this book will become a reference guide and will also help you to learn some possible new skills, or give you some new ideas you were never aware about. It will also help you to easily find the solution to some of the most well known problems you could find during your career as a DBA. This book contains useful screenshots, scripts, and examples that you will find more than useful. Most of the books currently available in the market concentrate only on the RMAN utility to backup and recovery. This book will be an exception to the rule and will become a must-have reference, allowing you to design a real and complete backup and recovery strategy. It covers the most important topics on Oracle database such as backup strategies, Nologging operations, new features in 12c, user managed backups and recoveries, RMAN (including reporting, catalog management, troubleshooting, and performance tuning), advanced data pump, Oracle Enterprise Manager 12c and SQL Developer. "Oracle Database 12c Backup and Recovery Survival Guide" contains everything a DBA needs to know to keep data safe and recoverable, using real-life scenarios.
Table of Contents (22 chapters)
Oracle Database 12c Backup and Recovery Survival Guide
Credits
About the Author
Acknowledgement
About the Author
Acknowledgement
About the Reviewers
www.PacktPub.com
Preface
Index

Hot backups


Oracle introduced hot backups back in version 6, allowing us take hot backups of our database tablespaces without the need to shut down the database like in earlier versions. Moreover in version 10g, Oracle gave us the ability to take hot backups of the entire database, making our life a little more easy. When executing a user-managed backup online, Oracle stops recording checkpoints to all the associated datafiles.

Let's take a deeper look at what's happening internally in the database when we use the BEGIN BACKUP option:

  • A hot backup flag in the datafiles header is set

  • A checkpoint occurs, flashing all dirty blocks from memory to disk, synchronizing all the datafile headers to the same SCN, and freezing the headers for consistency, protection, and recoverability

Hot backups (inconsistent backups due to fractured data blocks) can be made to the whole database, a tablespace or even at container level and it will require a recovery process after the backup is restored. Due to this...