Chapter 8. Page restores
It’s said that taking and verifying backups is a DBA’s first responsibility, but I believe that the most important thing is the ability to restore data when necessary, in as short a time as possible. That ability requires real knowledge and practical experience of effectively using the restore command, as well as the less commonly used page restore feature.
There are several possible granularities at which a database can be fully or partially restored. I suspect that everyone is familiar with the full restore, a replacement of the entire database with whatever was in the backup, but that’s far from the only option you have.
The database can also be restored at a filegroup level if ...