For very large Microsoft SQL Server databases, a complete restore operation can take many hours. During this time the database cannot be used to prevent data being entered and lost as information is copied back from tape or disk. In a high-availability environment, any downtime is costly, so keeping it to a minimum is essential.
Fortunately, page-level restore techniques can be used to keep recovery times to a minimum by reducing the amount of data that needs to copied back from the backup media. Since the release of Microsoft SQL Server 2005, DBAs have had the option of carrying out a ‘page level restore’ which allows them to recover a ‘handful’ of pages, rather than having to restore entire datasets and copy the information back into the original database.
The page-level restore operation is perfect for situations where data becomes corrupted during writes through a faulty disk controller, misconfigured antivirus software or an IO subsystem. Better still, restore level operations can be performed online for Enterprise editions of Microsoft SQL Server.