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Example: Online restore of a read-write file (full recovery model)

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Applies to: SQL Server

This article is relevant for SQL Server databases under the full recovery model that contain multiple files or filegroups.

In this example, a database named adb, which uses the full recovery model, contains three filegroups. Filegroup A is read/write, and filegroup B and filegroup C are read-only. Initially, all of the filegroups are online.

File a1 in filegroup A appears to be damaged, and the database administrator decides to restore it while the database remains online.

Note

Under the simple recovery model, online restore of read/write data isn't allowed.

Restore sequences

The syntax for an online restore sequence is the same as for an offline restore sequence.

  1. Online restore of file a1.

    RESTORE DATABASE adb FILE = 'a1' FROM backup
WITH NORECOVERY;

    At this point, file a1 is in the RESTORING state, and filegroup A is offline.

  2. After you restore the file, take a new log backup to make sure that the point at which the file went offline is captured.

    BACKUP LOG adb TO log_backup3;

  3. Online restore of log backups.

    You restore all the log backups taken since the restored file backup, ending with the latest log backup (log_backup3, taken in the previous step). After the last backup is restored, the database is recovered.

    RESTORE LOG adb FROM log_backup1 WITH NORECOVERY;
RESTORE LOG adb FROM log_backup2 WITH NORECOVERY;
RESTORE LOG adb FROM log_backup3 WITH NORECOVERY;
RESTORE DATABASE adb WITH RECOVERY;

    File a1 is now online.

Additional examples

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