Hello Dev, if you are a database administrator, you might already be familiar with SQL Server restore database. It’s a process of recovering a database from a backup. It’s a crucial aspect of your job, and you need to know how to do it correctly. In this article, we’ll discuss everything you need to know about SQL Server restore database. We’ll start with the basics and gradually move to more complex scenarios. So, let’s get started!
What is SQL Server Restore Database?
SQL Server restore database is a process of restoring a database from a backup. It means that you are recovering your data from a previously created backup file. You can restore your entire database or a portion of it, depending on your needs. You can also restore your database to a different server or to the same server. It’s a crucial aspect of database administration as it helps in recovering lost data due to various reasons such as hardware failure, software issues, or human error.
Why is SQL Server Restore Database Important?
SQL Server Restore Database is essential because it helps in recovering your data in case of any disaster. Suppose your server crashes or someone accidentally deletes critical data. In that case, you can use the backup file to restore your database to its previous state. It helps in reducing downtime, and you can get back to normal operations quickly. You can also use SQL Server restore database to restore your database to a different server or to the same server after a server upgrade or migration.
Types of SQL Server Restore Database
There are different types of SQL Server restore database that you should be aware of. Let’s discuss them one by one:
Type |
Description |
|---|---|
Full Restore |
It restores the entire database from a full backup file. |
Differential Restore |
It restores only the changes made since the last full backup. It’s faster than full restore. |
Transaction Log Restore |
It restores the database to a specific point in time. You need to restore the full backup and transaction logs. |
Piecemeal Restore |
It restores the database in portions, using multiple backup files. |
Now that you know the types of SQL Server restore database let’s discuss how to perform each type.
How to Perform SQL Server Restore Database?
Full Restore
Performing a full restore is a simple process. Let’s discuss the steps:
Step 1: Take a Backup of the Current Database
Before restoring your database from a backup file, it’s essential to take a backup of your current database. It’s a precautionary step in case something goes wrong during the restore process. You can use the following command to take a backup:
BACKUP DATABASE [database_name]TO DISK = 'C:\backup\database_name.bak'
Replace database_name with the name of your database and C:\backup\database_name.bak with the path and filename where you want to save the backup file.
Step 2: Restore the Full Backup
To restore the full backup, you can use the following command:
RESTORE DATABASE [database_name]FROM DISK = 'C:\backup\database_name.bak'WITH REPLACE, NORECOVERY
Replace database_name with the name of your database and C:\backup\database_name.bak with the path and filename of your backup file. The REPLACE option is used to overwrite the existing database if it exists. The NORECOVERY option is used to leave the database in a restoring state.
Step 3: Restore the Database Backup with No Recovery
After restoring the full backup, you need to restore the transaction logs. Before that, you need to tell SQL Server that you’re going to restore more backups. You can do that by using the following command:
RESTORE DATABASE [database_name]WITH NORECOVERY
This command tells SQL Server that you’re going to restore more backups.
Step 4: Restore the Differential Backup (Optional)
If you have a differential backup, you can restore it after the full backup. The differential backup contains only the changes made since the last full backup. To restore it, use the following command:
RESTORE DATABASE [database_name]FROM DISK = 'C:\backup\database_name_diff.bak'WITH NORECOVERY
Replace database_name with the name of your database and C:\backup\database_name_diff.bak with the path and filename of your differential backup file.
Step 5: Restore the Transaction Logs
After restoring the full backup and differential backup (if present), you need to restore the transaction logs. The transaction logs contain all the changes made to the database since the last backup. To restore them, use the following command:
RESTORE LOG [database_name]FROM DISK = 'C:\backup\database_name_log1.trn'WITH NORECOVERY
Replace database_name with the name of your database and C:\backup\database_name_log1.trn with the path and filename of your transaction log file. You also need to restore all the subsequent transaction logs.
Step 6: Restore the Database Backup with Recovery
After restoring all the necessary backups, you can restore the database with recovery. It means that the database is now ready to use. Use the following command:
RESTORE DATABASE [database_name]WITH RECOVERY
Replace database_name with the name of your database. This command completes the SQL Server restore database process.
Differential Restore
Performing a differential restore is similar to a full restore. The only difference is that you need to restore the full backup and the differential backup. Let’s discuss the steps:
Step 1: Take a Backup of the Current Database
Before restoring your database from a backup file, it’s essential to take a backup of your current database. It’s a precautionary step in case something goes wrong during the restore process. You can use the following command to take a backup:
BACKUP DATABASE [database_name]TO DISK = 'C:\backup\database_name.bak'
Replace database_name with the name of your database and C:\backup\database_name.bak with the path and filename where you want to save the backup file.
Step 2: Restore the Full Backup
You need to restore the full backup first. Use the following command:
RESTORE DATABASE [database_name]FROM DISK = 'C:\backup\database_name.bak'WITH REPLACE, NORECOVERY
Replace database_name with the name of your database and C:\backup\database_name.bak with the path and filename of your backup file. The REPLACE option is used to overwrite the existing database if it exists. The NORECOVERY option is used to leave the database in a restoring state.
Step 3: Restore the Differential Backup
After restoring the full backup, you need to restore the differential backup. Use the following command:
RESTORE DATABASE [database_name]FROM DISK = 'C:\backup\database_name_diff.bak'WITH NORECOVERY
Replace database_name with the name of your database and C:\backup\database_name_diff.bak with the path and filename of your differential backup file.
Step 4: Restore the Transaction Logs (Optional)
If you have transaction logs, you can restore them after the differential backup. The transaction logs contain all the changes made to the database since the last backup. To restore them, use the following command:
RESTORE LOG [database_name]FROM DISK = 'C:\backup\database_name_log1.trn'WITH NORECOVERY
Replace database_name with the name of your database and C:\backup\database_name_log1.trn with the path and filename of your transaction log file. You also need to restore all the subsequent transaction logs.
Step 5: Restore the Database Backup with Recovery
After restoring all the necessary backups, you can restore the database with recovery. It means that the database is now ready to use. Use the following command:
RESTORE DATABASE [database_name]WITH RECOVERY
Replace database_name with the name of your database. This command completes the SQL Server restore database process.
Transaction Log Restore
Transaction log restore is used to restore your database to a specific point in time. It means that you can restore your database to the exact state it was at a particular point in time. Let’s discuss the steps:
Step 1: Take a Backup of the Current Database
Before restoring your database from a backup file, it’s essential to take a backup of your current database. It’s a precautionary step in case something goes wrong during the restore process. You can use the following command to take a backup:
BACKUP DATABASE [database_name]TO DISK = 'C:\backup\database_name.bak'
Replace database_name with the name of your database and C:\backup\database_name.bak with the path and filename where you want to save the backup file.
Step 2: Restore the Full Backup
You need to restore the full backup first. Use the following command:
RESTORE DATABASE [database_name]FROM DISK = 'C:\backup\database_name.bak'WITH REPLACE, NORECOVERY
Replace database_name with the name of your database and C:\backup\database_name.bak with the path and filename of your backup file. The REPLACE option is used to overwrite the existing database if it exists. The NORECOVERY option is used to leave the database in a restoring state.
Step 3: Restore the Transaction Logs
After restoring the full backup, you need to restore the transaction logs. The transaction logs contain all the changes made to the database since the last backup. To restore them, use the following command:
RESTORE LOG [database_name]FROM DISK = 'C:\backup\database_name_log1.trn'WITH STOPAT = '2022-06-01 11:00:00.000', NORECOVERY
Replace database_name with the name of your database and C:\backup\database_name_log1.trn with the path and filename of your transaction log file. The STOPAT option is used to specify the point in time to which you want to restore your database. You can replace '2022-06-01 11:00:00.000' with your desired date and time. You also need to restore all the subsequent transaction logs.
Step 4: Restore the Database Backup with Recovery
After restoring all the necessary backups, you can restore the database with recovery. It means that the database is now ready to use. Use the following command:
RESTORE DATABASE [database_name]WITH RECOVERY
Replace database_name with the name of your database. This command completes the SQL Server restore database process.
Piecemeal Restore
Piecemeal restore is used when restoring a large database where backups are taken in parts. Let’s discuss the steps:
Step 1: Take a Backup of the Current Database
Before restoring your database from a backup file, it’s essential to take a backup of your current database. It’s a precautionary step in case something goes wrong during the restore process. You can use the following command to take a backup:
BACKUP DATABASE [database_name]TO DISK = 'C:\backup\database_name_part1.bak'WITH NOFORMAT, NOINIT, SKIP
Replace database_name with the name of your database and C:\backup\database_name_part1.bak with the path and filename where you want to save the backup file. The NOFORMAT option is used to exclude media format information from the backup file. The NOINIT option is used to skip the verification of the backup file. The SKIP option is used to skip the allocation of space to the backup file.
Step 2: Restore the Partial Backup
You need to restore the partial backup first. Use the following command:
RESTORE DATABASE [database_name]FROM DISK = 'C:\backup\database_name_part1.bak'WITH NORECOVERY
Replace database_name with the name of your database and C:\backup\database_name_part1.bak with the path and filename of your partial backup file.
Step 3: Restore the Differential Backup (Optional)
If you have a differential backup, you can restore it after the partial backup. The differential backup contains only the changes made since the last full backup. To restore it, use the following command:
RESTORE DATABASE [database_name]FROM DISK = 'C:\backup\database_name_part2_diff.bak'WITH NORECOVERY
Replace database_name with the name of your database and C:\backup\database_name_part2_diff.bak with the path and filename of your differential backup file.
Step 4: Restore the Transaction Logs
After restoring the partial backup and differential backup (if present), you need to restore the transaction logs. The transaction logs contain all the changes made to the database since the last backup. To restore them, use the following command:
RESTORE LOG [database_name]FROM DISK = 'C:\backup\database_name_part2_log1.trn'WITH NORECOVERY
Replace database_name with the name of your database and C:\backup\database_name_part2_log1.trn with the path and filename of your transaction log file. You also need to restore all the subsequent transaction logs.
Step 5: Restore the Next Partial Backup (Optional)
If you have more partial backups, you can restore them following the same procedure. Use the following command:
RESTORE DATABASE [database_name]FROM DISK = 'C:\backup\database_name_part3.bak'WITH NORECOVERY
Replace database_name with the name of your database and C:\backup\database_name_part3.bak with the path and filename of your next partial backup file.
Step 6: Restore the Transaction Logs (Optional)
If you have transaction logs for the next partial backup, you need to restore them. Use the following command:
RESTORE LOG [database_name]FROM DISK = 'C:\backup\database_name_part3_log1.trn'WITH NORECOVERY
Replace database_name with the name of your database and C:\backup\database_name_part3_log1.trn with the path and filename of your transaction log file. You also need to restore all the subsequent transaction logs.