The tail of the log for the database "DBName" has not been backed up

sql

backup-strategy

database-restore

sql-server

byAnton Shumikhin·Oct 30, 2024

Resolving "The tail of the log for the database 'DBName' has not been backed up" can be achieved by conducting a TAIL-LOG backup:

-- Commence operation 'Save Tail'. Don't you dare truncate, and remember, no recovery means no take-backs!
BACKUP LOG [DBName] TO DISK = 'DBName_TailLogBackup.trn' WITH NO_TRUNCATE, NORECOVERY;

This statement captures any remaining log records, paving the way for a point-in-time recovery. NO_TRUNCATE prevents data loss from incomplete transactions, and NORECOVERY tunes the database for a full restore sequence.

Acing the database restore

Overwriting an existing database

When the occasion calls for an existing database to be RESTORE DATABASE, the simple addition of WITH REPLACE can do the deed:

-- "Mission: Restore. Don't mind the other databases. They had their chance"
RESTORE DATABASE [DBName] FROM DISK = 'DBName_FullBackup.bak' WITH REPLACE;

Bear in mind, WITH REPLACE rides roughshod over any existing data in the database, so be armed with the certainty that your database's current state can be let go.

Troubleshooting restoration glitches

Restore processes can end prematurely due to system processes or user transactions locking the database. Before embarking on a restore, ensure no such process is running.

Recovery model and restore operations

The recovery model of your database has direct ramifications on the conduct of backup and restore operations. Opting for a Simple recovery model might make the process less onerous, but it also trims the finer control achievable with the Full recovery model.

Overcoming persistent restore issues

In the face of persisting issues, check the following:

Ensure the database isn't being actively manipulated by users or applications.
All database dependencies such as replication or mirroring are correctly managed.

Turning to professional assistance or consulting the official documentation may be your best recourse when stuck.

Point-in-time recovery

One can leverage the WITH STOPAT clause to mark the restoration point:

-- "Shh. Listen to the whispers of the past. Ok, stop... Right there!""
RESTORE DATABASE [DBName] FROM DISK = 'DBName_FullBackup.bak'
WITH STOPAT = 'YYYY-MM-DD HH:MM:SS', REPLACE;

Using WITH STOPAT should be aligned with your data retention policy to avoid losing critical historic data.

Establishing backup reliability

Checking backup history

To ensure your backup strategy is watertight, routinely inspect your backup history for consistency.

Taking pre-backup precautions

Executing a BACKUP LOG WITH NORECOVERY pre-restore ensures any ongoing tasks aren't lost:

-- "Before the endgame kicks off, let's save our marvels!"
BACKUP LOG [DBName] TO DISK = 'DBName_PreRestoreLogBackup.trn' WITH NORECOVERY;

Verifying database state post-restore

After a restore, always verify the operating state. Run your staple queries and application checks to ascertain the operational state of the database.