How to Restore Differential Backups in SQL Server?

Differential backups play a significant role when it comes to the recovery of SQL Server databases in case of any issue. These backups only capture the changes made to the database since the last full backup. Due to this, the restoration process becomes more efficient and the downtime is reduced. In this article, we will understand the concept of differential backups and explain the step-by-step process to restore them.

Understanding Differential Backups

?Differential backups are incremental backups that capture only the changes made to a database since the last full backup. They serve as a “middle ground” between full backups (which capture the entire database) and transaction log backups (which capture changes made since the last backup - either full or differential). Differential backups significantly reduce the time and resources required for database restoration compared to full backups.

How to Create a Differential Backup?

?Before discussing the process of restoring differential backups, it is essential to understand how to create them. To create a differential backup in MS SQL Server, simply follow these steps:

·?????? Launch the SQL Server Management Studio (SSMS): Launch SSMS and connect to the SQL Server instance containing the database you want to back up.

·?????? Select the Database: In the Object Explorer, expand the Databases node, right-click on the desired database, and choose Tasks > Back Up.

·?????? Select Backup Type: In the Backup Database window, select "Differential" as the backup type.

·?????? Choose Destination: Choose the destination to save the backup file. You can create a new backup file or overwrite an existing one.

·?????? Configure Backup Options: Review and configure backup options, such as compression, encryption, and backup expiration.

·?????? Initiate Backup: Click the "OK" button to initiate the backup process.

?How to Restore Differential Backup in SQL Server?

?You can restore a differential backup in SQL Server by following the given steps:

·?????? Open SSMS: Launch SSMS and connect to the SQL Server instance where you want to restore the database.

·?????? Go to Restore Database Wizard: In the Object Explorer, right-click on the "Databases" node and choose "Restore Database." This will open the Restore Database wizard.

·?????? Select the Source: In the wizard, select "Device" as the source and click the ellipsis (...) button to choose the backup file containing the differential backup.

·?????? Specify Backup Media: In the "Specify Backup" window, select the differential backup set you want to restore.

·?????? Review Restore Options: Review and configure restore options, including the destination database name, file path, and more.

·?????? Start the Restore Process: Click the "OK" button to initiate the restoration process. SQL Server will restore the differential backup and apply it to the previously restored full backup, bringing the database up to the point of the differential backup.

Once the restoration process is complete, you will receive a confirmation message.

You can restore the differential backup in the SQL server using TSQL:

Open SSMS: Launch SSMS and connect to the SQL Server instance where you want to restore the database

In SSMS, open a new query window.

RESTORE DATABASE Stellar

FROM DISK = 'C:\Path\To\YourFullBackup.bak'

WITH NORECOVERY;        

-- Restore the differential backup

RESTORE DATABASE Stellar

FROM DISK = 'C:\Path\To\YourDifferentialBackup.bak'

WITH RECOVERY;        

RESTORE DATABASE Stellar WITH RECOVERY statement to bring the database online.

RESTORE LOG Stellar

FROM DISK = 'C:\Path\To\YourTransactionLogBackup.trn'

WITH NORECOVERY;

Then bring Database Online:

RESTORE DATABASE YourDatabaseName WITH RECOVERY;        

?Your Database will be restored.

Tips for Effective Backup Creation and Recovery

It is important to ensure the effectiveness of your backup and recovery strategy. You can follow the given best practices that can help you in your backup and restore strategy:

·?????? Regular Backups: Schedule regular full and differential backups to capture changes efficiently.

·?????? Test Restoration: Periodically test the restoration of your backups to ensure they are valid and can be successfully restored when needed.

·?????? Monitor for Corruption: Implement database monitoring to detect corruption issues and take corrective actions.

·?????? Documentation: Document everything related to your backup and recovery procedures. This will facilitate efficient recovery in case of emergency.

What if the Backup gets Corrupted?

Differential backups are not immune to corruption. Corruption can occur due to various reasons, such as disk errors, hardware failure, or software issues. In such cases, you can rely on an advanced SQL database repair tool, like Stellar Repair for MS SQL.

Stellar Repair for MS SQL is a powerful tool designed to repair and recover data from corrupted SQL Server databases and backup files, including differential backup. By using this software, you can salvage valuable data from corrupted differential backup files, ensuring minimal data loss and reducing downtime.

?Conclusion

Differential backups in SQL Server play an important part in database management and disaster recovery. These backups help in efficiently recovering your database to a specific point in time, reducing data loss and minimizing downtime. Above, we have explained the detailed process of creating and restoring differential backups in SQL Server. However, in case your differential backup becomes corrupted, a robust tool like Stellar Repair for MS SQL can come in handy. It can recover your critical data from damaged/corrupted backup files.