What is the best way to handle database backups and recovery?

1 Backup Types

When considering backups for a database, there are various types that can be utilized depending on the needs and resources. Full backups are the most reliable and comprehensive but also the most time-consuming and space-consuming. Differential backups, on the other hand, are partial copies of the database containing only data that has changed since the last full backup, and they require a full backup to be restored. Lastly, incremental backups are also partial copies of the database, containing only data that has changed since the last backup, either full or differential. This type of backup is the fastest and smallest but requires all previous backups to be restored.

2 Backup Frequency

The frequency of your backups depends on how often your data changes and how much data loss you can tolerate. Generally, you should backup your data as often as possible to capture the latest state of the database, but also consider the impact of the backup process on performance and availability. Factors influencing the backup frequency include the size of your database, rate of data change, recovery point objective (RPO), and backup window. A larger database takes longer to backup and requires more storage space, while a shorter backup window means a lower backup frequency. The lower the RPO, the higher the backup frequency must be to ensure that data is not lost in case of a failure or disaster.

3 Backup Storage

The storage of your backups is a key part of your backup strategy. You should store your backups in a secure and reliable location, such as off-site or in the cloud, to protect them from physical damage, theft, or corruption. It's also wise to have multiple copies of your backups in case one fails or gets lost. When considering the storage of your backups, there are several factors to consider, such as the storage medium (e.g. tapes, disks, or cloud services), the storage format (e.g. binary, compressed, or encrypted), and the retention period (defined by legal, regulatory, or business requirements). Additionally, you should delete or overwrite old backups to free up space and minimize confusion.

4 Recovery Types

When recovering a database, the most common approaches are restoring, rolling back, and rolling forward. Restoring involves copying data from a backup to the original or new location; however, it may cause data loss depending on the age of the backup. Rolling back involves undoing changes made to the database since the last backup with the help of the transaction log. It is more complex than restoring but can minimize or eliminate data loss. Finally, rolling forward applies changes made to the database after the last backup, using the transaction log or other sources. This is also complex and less common than restore or rollback, but it can recover the most recent state of the database if sources are available and accurate.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?