Backup Without Checksum

One of the key challenges of maintaining a database is ensuring that backups are reliable and can be restored in the event of data loss. To help address this issue, SQL Server provides the CHECKSUM option for backups, which allows administrators to verify the integrity of the backup data.

When the CHECKSUM option is used, SQL Server calculates a checksum for the data in the backup as it is being written to the backup file. This checksum is then stored in the backup file along with the data. When the backup is restored, SQL Server calculates a checksum for the data being restored and compares it to the checksum stored in the backup file. If the checksums do not match, it indicates that the data in the backup file may be corrupt and the restore process will fail.

Using the CHECKSUM option for backups provides several benefits, such as:

  • Ensuring the integrity of the backup data: By verifying the checksum of the data in the backup file, administrators can be confident that the data can be restored accurately in the event of data loss.
  • Detecting data corruption early: If the data in the backup file is corrupt, the restore process will fail when the CHECKSUM option is used. This allows administrators to detect data corruption early, before it becomes a more serious issue.
  • Improving restore performance: When the CHECKSUM option is not used, SQL Server has to read the entire backup file to ensure that it is not corrupt. This can impact restore performance, as the backup file has to be read in its entirety. When the CHECKSUM option is used, the restore process only has to read the checksum from the backup file, which is much faster.

To use the CHECKSUM option for backups, the administrator can specify the CHECKSUM option in the BACKUP statement when creating the backup. For example:

BACKUP DATABASE MyDatabase
TO DISK = 'C:\MyDatabase.bak'
WITH CHECKSUM;

Using the CHECKSUM option for backups can help ensure the reliability and integrity of the backups, as well as improve restore performance. This can provide peace of mind for administrators and reduce the risk of data loss in the event of a disaster.

It is recommended to always use checksum on SQL Server backups.