Chapter 10. Backup and recovery
In this chapter, we’ll cover
- Backup types
- Recovery models
- Online piecemeal restore
- Database snapshots
- Backup compression
The importance of backups can’t be overstated. During normal activity, it’s easy to view backing up databases as an administrative chore that complicates the day and offers little benefit. However, when required in an emergency, the presence of valid backups could make all the difference to an organization’s ongoing survival. As DBAs, we have a vital role to play in that process.
Successful backup strategies are those that are designed from a restore perspective—that is, they begin with service level agreements covering data loss and restoration times, and work backwards to derive the backup design. Second only to not performing backups, the biggest backup-related mistake a DBA can make is failing to verify backups. There are countless stories of backup tapes being recalled for recovery before finding out that the backups have been failing for the past few months (or years!). While the backup may appear to have succeeded, how can you be sure until you actually restore it?