Chapter 18: Backup and Recovery

Overview

Data is a very important asset for an organization to maintain information about their customers, inventory, purchases, financials and products. Over the course of many years, organizations amass information to improve daily customer experience, as well as to leverage this information to support strategic decisions. Downtime is unacceptable and can be costly for the organization; for example, a stock brokerage house cannot take stock orders or an airline cannot sell tickets without their databases. Every hour the database is down can add up to millions of dollars of business opportunity lost. To keep their business activities going, organizations deploy high-availability solutions as failover clustering, data mirroring, and log shipping so that when a database server fails, they can continue to run their business on a standby database server. All of these topics are covered in other chapters in this book. Additionally, a SAN system is protected by fault-tolerant disk arrays. In addition, to protect from a local disaster, businesses normally have a disaster recovery plan to handle a situation where the site where the organization does its business is down and needs to quickly redeploy the data center to continue to serve customers.

While a high-availability solution tries to keep the business data online, a database backup plan is crucial to protect the business data asset. If there is a data-error problem and the database is unrecoverable, the DBA can use the database backup to recover the database to a consistent state. Moreover, the database backup strategy will try to reduce the amount of data loss in case of an error problem encountered during the course of the daily database activities. In this chapter, we first present an overview of backup and restore. Then we walk you through planning and developing a backup plan, managing backups, and performing restores. We also discuss data archiving and disaster recovery planning.