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Welcome to our guide on SQL Server Backup and Recovery. As a critical aspect of database management, understanding how to systematically back up and recover your SQL Server database will ensure that your data remains safe, even when faced with a catastrophe.
Understanding SQL Server Backup
First off, creating a database backup simply means making a copy of your database. This copy can be used in the case of a disaster as a source to restore your data. SQL Server provides a few different types of backup namely: full, differential, and transaction log backup.
1. Full Backup
Full backup means backing up the whole database. It’s the base of both differential backup and transaction log backup. Here is an example of SQL code you would write to perform a full backup of a database called ‘myDatabase’:
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BACKUP DATABASE myDatabase TO DISK = 'C:\Backups\myDatabase.bak'; |
2. Differential Backup
After the full backup, you might want to save the storage by only backing up the changed or added part of the database since the last backup. Here is how it can be done:
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BACKUP DATABASE myDatabase TO DISK = 'C:\Backups\myDatabase.bak' WITH DIFFERENTIAL; |
3. Transaction Log Backup
Transaction log backups can be used in combination with full database backups to restore the database to a point of time. This is how you can do this:
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BACKUP LOG myDatabase TO DISK = 'C:\Backups\myDatabase_Log.bak'; |
Understanding SQL Server Recovery
With the backup ready and kept safely, let’s understand how recovery works. SQL Server offers different recovery models namely: Simple, Full, and Bulk-Logged.
Restoring a Backup
To restore a database from a full backup, use the RESTORE DATABASE command, as shown in the example below:
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RESTORE DATABASE myDatabase FROM DISK = 'C:\Backups\myDatabase.bak'; |
Restoring a database may require several steps, depending on the type and number of backups you have made.
Conclusion
Database backup and recovery is vital in maintaining data integrity and availability. Understanding and implementing SQL Server backup and recovery procedures will ensure your data remains safe and accessible. Practice these commands, make them a routine part of your database administration, and you will be well on your way to mastering SQL Server!