Recovery Paths

Administering SQL Server

Administering SQL Server

Recovery Paths

A new recovery path is created if you recover a database to an earlier point in time and begin using the database from that point. This recovery path will contain new transactions that make it unique. If you need to restore the database again, it is not possible to combine the data from the two recovery paths. You must restore data along one path or the other.

Note  Restoring a full database backup and recovering the database without using any other type of backup does not result in a new recovery path.

Examples of when a new recovery path is created include:

  • Restoring a full database backup and a differential backup and recovering the database without applying existing transaction log backups.

  • Recovering the database at the end of a differential backup other than the most recent differential backup.

  • Recovering the database at the end of a transaction log backup other than the most recent transaction log backup.

  • Recovering the database at a specific time or a marked transaction within a transaction log backup.

In the example above, a Full Database Backup and a sequence of four Log Backups are created. The database is then restored to the end of Log Backup 2 by restoring the Full Database Backup, Log Backup 1, and Log Backup 2. The database is recovered at this point, creating a new recovery path. The database is then used for a time, and two more transaction log backups, Log Backup 5 and Log Backup 6, are created. If you again restore the Full Database Backup and apply transaction log backups, you must follow one of the two recovery paths:

  • Log Backup 1, Log Backup 2, Log Backup 3, and Log Backup 4

    -or-

  • Log Backup 1, Log Backup 2, Log Backup 5, and Log Backup 6

The database can be recovered at any point in time along either path, but it is not possible to combine data from the two. For example, you cannot restore Log Backups 1 through 6 in sequence because Log Backups 3 and 4 contain data that is inconsistent with Log Backups 5 and 6.