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

Purpose of backup and recovery


As a DBA, you are the person responsible for recovering the data and guarding the business continuity of your organization. Consequently, you have the key responsibility for developing, deploying, and managing an efficient backup and recovery strategy for your institution or clients that will allow them to easily recover from any possible disastrous situation. Remember, data is one of the most important assets a company can have. Most organizations would not survive after the loss of this important asset.

Testing backups

It's incredible how many corporations around the world do not have a proper disaster recovery plan (DRP) in place, and what is worse, many DBAs never even test their backups. Most of the time when auditing Oracle environments for clients, I ask the following question to the DBA team:

  • Are you 100 percent sure that you can trust your backups? For this question I generally receive answers like:

    • I'm not 100 percent sure since we do not recover from backups too often

    • We do not test our backups, and so I cannot guarantee the recoverability of them

Another good question is the following:

  • Do you know how long a full recovery of your database will take? Common responses to this question are:

    • Probably anything between 6 and 12 hours

    • I don't know, because I've never done a full recovery of my database

As you can see, a simple implementation of a procedure to proactively test the backups randomly will allow you to:

  • Test your backups and ensure that they are valid and recoverable: I have been called several times to help clients because their current backups are not viable. Once I was called to help a client and discovered that their backup-to-disk starts every night at 10 P.M. and ends at 2 A.M. Afterwards, the backup files are copied to a tape by a system administrator every morning at 4 A.M. The problem here was that when this process was implemented, the database size was only 500 GB, but after few months, the size of the database had grown to over 1 TB. Consequently, the backup that was initially finishing before 2 A.M. was now finishing at 5 A.M., but the copy to a tape was still being triggered at 4 A.M. by the system administrator. As a result, all backups to a tape were unusable.

  • Know your recovery process in detail: If you test your backups, you will have the knowledge to answer questions regarding how long a full recovery will take. Answering that your full recovery will take around three and a half hours, but you prefer to say five hours just in case of any unexpected problem that you will come across, you will look more professional. This will let me know that you really know what you are talking about.

  • Document and improve your recovery process: The complete process needs to be documented. If the process is documented and you also allow your team to practice on a rotation basis, this will ensure that they are familiar with the course of action and will have all the knowledge necessary to know what to do in case of a disaster. You will now be able to rest in your home at night without being disturbed, because now you are not the only person in the team with the experience required to perform this important task.

Good for you if you have a solid backup and recovery plan in place. But have you tested that plan? Have you verified your ability to recover?