SQL Server on Azure VM and Azure SQL Database are two different options for hosting and managing SQL Server instances on the Azure cloud platform. While both options provide SQL Server functionality, there are some key differences that may influence which option you choose for your specific needs.
Here are some of the main differences between SQL Server on Azure VM and Azure SQL Database:
Deployment and Management:
SQL Server on Azure VM involves deploying a virtual machine on Azure and then installing and configuring SQL Server on that virtual machine. You are responsible for managing and maintaining the virtual machine and SQL Server instance, including backups, security, and updates.
Azure SQL Database, on the other hand, is a fully managed database service that handles most of the deployment and management tasks for you. Microsoft manages the underlying infrastructure, including backups, security, and updates, leaving you free to focus on your data and applications.
With SQL Server on Azure VM, you can scale up or down the virtual machine as needed to meet your performance and capacity requirements. However, scaling up or down can be time-consuming and may require downtime.
Azure SQL Database, on the other hand, provides automatic scaling and resource allocation, allowing you to quickly and easily adjust capacity as needed. This can help you optimize performance and reduce costs by only paying for the resources you need.
High Availability and Disaster Recovery:
SQL Server on Azure VM requires you to implement your own high availability and disaster recovery (HADR) solutions, such as database mirroring, failover clustering, or Always On Availability Groups. This can be complex and time-consuming to set up and maintain.
Azure SQL Database, on the other hand, provides built-in HADR features, such as geo-replication and automatic failover, to ensure your data is always available and protected. This can help you reduce downtime and minimise the risk of data loss.
With SQL Server on Azure VM, you are responsible for implementing and maintaining your own security measures, such as firewalls, encryption, and access controls. This can be challenging and time-consuming, especially if you are not a security expert.
Azure SQL Database, on the other hand, provides built-in security features, such as encryption, auditing, and threat detection, to help you protect your data and comply with industry standards and regulations.
SQL Server on Azure VM may be a more cost-effective option for long-term usage or for workloads that require large amounts of storage or memory. With SQL Server on Azure VM, you pay for the virtual machine and storage separately, which can be more cost-effective for larger workloads.
Azure SQL Database, on the other hand, is a fully managed service with a pay-as-you-go pricing model, which means you pay only for what you use. This can be more cost-effective for smaller workloads or for workloads that require frequent scaling up or down.
SQL Server on Azure VM provides full compatibility with on-premises SQL Server instances, which means you can migrate your existing applications and databases to the cloud without any changes to your code or database schema.
Azure SQL Database, on the other hand, is a platform-as-a-service (PaaS) solution that provides limited compatibility with on-premises SQL Server instances. While most T-SQL commands and features are supported, there may be some differences in behavior or syntax that require changes to your code or database schema.
SQL Server on Azure VM provides dedicated hardware resources, which can provide higher performance and lower latency for certain workloads. However, performance can be affected by other factors, such as the size and configuration of the virtual machine and the network connectivity.
Azure SQL Database, on the other hand, provides a highly optimised and scalable database engine that is designed to handle large workloads with low latency and high throughput. Azure SQL Database also provides built-in performance monitoring and tuning tools to help you optimize your queries and indexes.
Backup and Restore:
SQL Server on Azure VM requires you to implement your own backup and restore strategy, which can be complex and time-consuming. You need to configure and manage backup schedules, storage accounts, and retention policies.
Azure SQL Database, on the other hand, provides built-in backup and restore capabilities that automatically backup your database to Azure Storage and allow you to restore to any point in time within a retention period of up to 35 days. Azure SQL Database also provides automated geo-replication to a secondary region for disaster recovery purposes.
SQL Server on Azure VM provides greater control and flexibility, but requires more management and maintenance on your part. Azure SQL Database provides a fully managed, scalable, and highly available database service, but with less control over the underlying infrastructure. Ultimately, the choice between the two options depends on your specific needs, skills, and resources.