This page describes how backups of your Cloud SQL instance work, and how they can be used to restore your data to the same or another instance.
For step-by-step directions for scheduling backups or creating an on-demand backup, see Creating and Managing On-Demand and Automatic Backups.
What backups provide
Backups provide a way to restore your Cloud SQL instance to recover lost data or recover from a problem with your instance. You should enable automated backups for any instance that contains data that you need to protect from loss or damage.
What backups cost
Cloud SQL retains up to 7 automated backups for each instance. The storage used by backups is charged at a reduced rate. See the pricing page for more information.
About backup size
Cloud SQL backups are incremental; they contain only data that has changed since the previous backup was taken. This means that your oldest backup is a similar size to your database, but the sizes of subsequent backups depend on the rate of change of your data. When the oldest backup is deleted, the size of the next oldest backup increases so that a full backup still exists.
When backups are created
When you enable automated backups, you specify a 4-hour backup window. The backup will start during the backup window. When possible, schedule backups when your instance has the least activity.
If your data has not changed since your last backup, no backup is taken.
About on-demand backups
You can create a backup at any time. This could be useful if you are about to perform a risky operation on your database, or if you need a backup and you do not want to wait for the backup window. You can create on-demand backups for any instance, whether the instance has automatic backups enabled or not.
On-demand backups are not automatically deleted the way automated backups are. They persist until you delete them. This affects your storage charges.
About the special backup user
Cloud SQL creates a special database user,
cloudsqladmin, for each
instance, and generates a unique instance-specific password for it.
Cloud SQL logs in as the
cloudsqladmin user to perform automated backups.
How backups affect instance operations
Writes and other operations are unaffected by backup operations.