Managing Database Backup and Recovery - High-Performance Web Databases: Design, Development, and Deployment - page 689

Chapter 51

Managing
Database Backup
and Recovery

Michael Simonyi

INTRODUCTION

Management of the corporate database is arguably one of the most mis-
managed areas in information technology today. Database technology has
evolved from historical glass-house foundations of the past into the point-
and-click implementations that come right out of the box today. Where
databases and systems were once carefully designed, implemented, and
deployed, they are now installed, loaded, and deployed without regard to
basic effective design. This article addresses the concepts necessary to
formulate a method to protect, back up, and, in the event of failure, recover
perhaps the most important aspect of a business — its database. Without
proper preparation, planning, and testing, an entire database infrastruc-
ture can become the target of lost devices, indexes, degraded backup
mechanisms, and corrupted data.

HIGH AVAILABILITY VS. RECOVERABILITY

There are important differences between database availability and
recoverability. Database availability can be a driving factor to recoverabil-
ity, but it does not guarantee recoverability. Database availability is the
measurement of production uptime and physical access to production
data in a networked environment. In contrast, database recoverability
refers to the ability to recover a database successfully in its entirety. Recov-
erability is a measurement of how accurate and lengthy the process of
recovering from partial or total failure can be. The difference lies in the
application of backup tools used in conjunction with high-availability tools.
The redundancy of high-availability systems in an environment can
directly relate to a higher grade of successful backups for the database
environment as well as the supporting systems. In this article, a database