What Is Azure SQL Database?
Azure SQL Database is Microsoft Azure’s fully managed relational database service, designed to handle Microsoft SQL Server (MSSQL) workloads in the cloud without the need for infrastructure management. It features built-in intelligence that learns application patterns to enhance performance, reliability, and data security.
This database service delivers dynamic scalability with the option for a serverless compute model, which automatically scales resources based on workload demands. It supports a range of applications, from small projects to large-scale enterprise databases. It helps ensure high availability, provides security features, and supports automatic backups with minimal management overhead.
This is part of a series of articles about Azure backup
In this article:
- Why Is It Critical to Backup Your Azure SQL Database?
- Types of Backups in Azure SQL Database
- Azure SQL Database Backup Use Cases
- Tutorial: Configure Backups for Azure SQL Database
Why Is It Critical to Backup Your Azure SQL Database?
Backing up Azure SQL Database is essential, even with its built-in redundancy and high availability features, due to several critical factors:
- Data loss prevention: While Azure provides geo-redundancy and automated failovers, it does not protect against user errors such as accidental deletions or modifications. Backups ensure you can restore your database to a specific point in time, mitigating the impact of such errors.
- Compliance and regulatory requirements: Many industries have strict regulations regarding data retention and recovery. Regular backups help meet these legal obligations by ensuring data can be restored when required.
- Business continuity: In the event of a catastrophic failure or corruption, backups allow for the swift restoration of services, minimizing downtime and its associated costs. This is crucial for maintaining customer trust and operational efficiency.
- Flexibility in recovery: Backups provide the ability to restore not just the entire database but also individual tables or data subsets. This granularity is useful in scenarios where only specific parts of the database are affected.
- Testing and development: Backups can be used to create replicas of the production environment for testing and development purposes without affecting the live database. This facilitates a safe environment for application testing and development.
Types of Backups in Azure SQL Database
Azure SQL Database supports several data backup strategies.
Full Backups
Full backups include the entire database and its associated transaction logs. They capture the state of the database at a given point in time, ensuring that all data can be restored in case of data loss or corruption. Azure SQL Database automatically performs full backups on a weekly basis, providing a foundational layer of data protection and recovery capability.
Full backups are essential for disaster recovery scenarios as they allow for the restoration of the entire database without the need for incremental or differential backups. This process simplifies recovery procedures by providing a single restore point, reducing complexity. These backups are stored in geo-redundant storage, ensuring high availability in case of regional outages.
Differential Backups
Differential backups capture only the changes made since the last full backup, significantly reducing the size and time needed for backups. This type of backup provides an efficient way to maintain up-to-date data protection without the overhead of performing full backups frequently. Azure SQL Database schedules differential backups every 12 or 24 hours, depending on the database’s workload and activity.
By incorporating differential backups, organizations can achieve quicker recovery times. In the event of data loss or corruption, a recent differential backup can be restored along with the last full backup, quickly bringing databases back to their most recent state with minimal data loss.
Transaction Log Backups
Transaction log backups capture all the transactions that have occurred since the last log backup. This type of backup is crucial for restoring a database to a specific point in time, offering fine-grained recovery options. Azure SQL Database performs transaction log backups approximately every 10 minutes, ensuring that recent changes are frequently captured and can be restored with minimal data loss.
The ability to restore from transaction log backups aids in maintaining business continuity, especially in scenarios where precise data recovery is required. For example, if an unintended data modification or deletion occurs, administrators can use transaction log backups to recover the database to the moment just before the undesired change was made. This backup strategy significantly reduces the risk associated with data corruption or accidental modifications.
Related content: Read our guide to Azure backup pricing (coming soon)
Here are 5 tips that can help effectively manage Azure SQL Database backups:
- Automate Backup Verification: Regularly test your backups by automating the restore process to a non-production environment. This ensures the backups are valid and can be restored without issues.
- Leverage Immutable Storage: Store critical backups in immutable storage to protect against ransomware and ensure that backups cannot be altered or deleted within a specified retention period.
- Implement Cross-Subscription Backups: For additional security, consider storing copies of your backups in a different Azure subscription to safeguard against subscription-level issues or compromises.
- Use Private Endpoints for Backup Operations: Configure private endpoints to ensure that backup and restore operations occur over secure, private connections rather than the public internet, enhancing security.
- Encrypt Backup Data: Ensure that all backups are encrypted using transparent data encryption (TDE) for in-use data and encryption-at-rest for stored backup data to enhance security and compliance.
Azure SQL Database Backup Use Cases
Azure SQL Database can be used for the following backup scenarios.
Restore an Existing Database to a Point in Time
Restoring an existing database to a specific point in time helps in handling data loss or corruption scenarios. This process uses the automatically managed backups—full, differential, and transaction log backups—to recover the database to a state just before an undesired event occurred.
The restoration involves identifying the exact point in time required for recovery and initiating the restore operation through Azure’s management portal, PowerShell, or CLI tools. This feature is useful for quickly addressing issues such as accidental data deletion or application errors that compromise database integrity.
The restore operation creates a new instance of the database at the specified point in time, ensuring no impact on the current live database while enabling thorough verification of recovered data. Once validated, this newly restored database can replace the original one or be used to retrieve items of data.
Restore a Deleted Database to a Point in Time
Azure SQL Database uses an automatic backup system that retains backups for a set period even after a database is deleted. This ensures that accidental or premature deletions do not result in permanent data loss.
To initiate the restoration, users specify the deletion time as the restore point within the retention period, leveraging Azure’s management tools. The process creates a new instance of the deleted database on its original server, undoing the deletion and recovering all data up to the specified moment.
This feature helps protect against accidental deletions. It simplifies recovery by automating backup retention and restoration processes, minimizing the administrative burden and reducing downtime.
Restore a Database to Another Geographic Region
Azure SQL Database offers a geo-redundant backup feature, useful for disaster recovery scenarios where the primary region is not accessible due to outages or regional disruptions. By storing backups in geo-redundant storage, Azure SQL Database ensures a copy of the data is available in a secondary region, enabling restoration when the primary region is compromised.
To initiate a geo-restore, users select the desired backup and target region through Azure’s management portal or automation tools. The system then creates a new database instance in the target region using the selected backup. This helps maintain business continuity and data availability across geographic boundaries, protecting against regional failures.
Restore a Database from a Long-Term Backup
Azure SQL Database supports restoring a database from a specific long-term backup using a Long-Term Retention (LTR) policy, which allows backups to be retained for up to 10 years. This is useful for compliance with regulatory requirements and for scenarios where historical data needs to be accessed or analyzed.
To perform a restore from an LTR backup, users specify the backup’s timestamp through Azure’s management tools, initiating the creation of a new database instance based on this historical data. This feature ensures that even very old data can be recovered, supporting various business and legal requirements.
Tutorial: Configure Backups for Azure SQL Database
Here’s a step-by-step guide to configuring backups using Azure SQL Database. The instructions are adapted from an official Azure training module.
Create a Logical Server and Database
Using Azure CLI, you can execute commands to create a logical server and database:
- First, set up some variables:
$serverName = "myserver-$(Get-Random)"
$location = $(Get-AzResourceGroup -ResourceGroupName [name of sandbox resource group]).location
$sqlAdmin = Get-Credential -credential dbadminThis script generates a unique server name, determines the location from your resource group, and sets up admin credentials.
- Next, create the logical server:
New-AzSqlServer `
-ResourceGroupName [name of sandbox resource group] `
-Location $location `
-ServerName $serverName `
-SqlAdministratorCredentials $sqlAdmin- Then, create the database:
New-AzSqlDatabase `
-ResourceGroupName [name of sandbox resource group] `
-ServerName $serverName `
-DatabaseName sql-my-dbBy default, this creates a general-purpose database with Standard-series hardware and 2 vCores.
Configure a Backup Retention Policy
To configure the backup retention policy for the database:
- In the Azure portal, navigate to All resources and select the myserver-NNNN logical server.
- For Data management, choose Backups.
- Open the Retention policies tab and click on the sql-my-db database.
- Move the Point-in-time-restore slider bar to 28 days.
- Click Apply, then confirm the selection.
Enable Network Access
To enable network access to the database logical server:
- Navigate back to the myserver-NNNN logical server.
- Click on Security, then Networking.
- For Firewall rules, select the Add your client IPv4 address option. Input your IP address.
- For Exceptions, check the box to allow Azure services and resources to access the server.
- Click Save.
Add Data to the Database
To add data:
- Go to Settings and select SQL databases, then sql-my-db.
- In the left menu, select Query editor (preview), and log in with the dbadmin credentials.
- Create a table:
CREATE TABLE Products
(
ProductId INT IDENTITY PRIMARY KEY,
ProductName NVARCHAR(100) NOT NULL,
Price DECIMAL(10, 2) NOT NULL,
Quantity INT NOT NULL
);- Insert a record:
INSERT INTO Products (ProductName, Price, Quantity)
VALUES ('Laptop', 999.99, 10);- Query the database to verify the record:
SELECT * FROM dbo.Products;This completes the setup and ensures you have data for validating backup and restore processes.
Azure SQL Database Backup at Lower Cost, Better Security, and Improved Scalability with N2WS
N2WS Backup & Recovery offers several features that significantly enhance the backup and recovery capabilities for Azure SQL Database, offering benefits in terms of cost efficiency, scalability, and security.
No-cost Azure Backups
Unlike Azure Backup, which has a fixed service cost and charges per number of protected instances, N2WS does not have fixed service costs. You can manage backups for free and only pay for Azure storage and bandwidth costs.
Backing up from AWS to Azure
N2WS enables data lifecycle management from AWS to an Azure repository. This feature allows users to archive snapshots from AWS instances and volumes to a storage account in Azure, optimizing long-term storage costs.
Immutability
Users can make backups immutable, adding a layer of security by preventing data changes during the retention period. This cross-cloud archiving not only reduces storage costs but also meets various compliance requirements.
Better security
For users who prioritize security and compliance, N2WS supports multi-factor authentication (MFA). This feature adds an extra layer of protection to user accounts by requiring a temporary code sent via email or generated by an authenticator app.
Improved scalability
N2WS enhances scalability with features like agentless SQL backups using worker instances. This capability allows for efficient backup and recovery of SQL databases, leveraging Azure-native snapshots. The agentless approach improves performance and scalability, ensuring that production databases are regularly backed up and can be swiftly restored.
Additionally, the enhanced VPC Capture & Clone capabilities now support IPv6 and provide improved scalability for complex environments, ensuring that network configurations can be efficiently managed and recovered.
