Azure SQL
Azure SQL is a family of managed, secure, and intelligent database services provided by Microsoft Azure
that uses the SQL Server engine in the cloud. This suite of services lets you choose the level of
administration you want, from fully managed options to hosting SQL Server on a virtual machine.
Azure SQL Family
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Azure SQL Database (PaaS):
A fully managed Platform-as-a-Service (PaaS) relational database service built for the cloud.
It handles upgrades, patching, backups, and monitoring with minimal user intervention.
Deployment options: Single database, elastic pool, or serverless compute tier that scales automatically.
-
Azure SQL Managed Instance (PaaS):
Provides near-100% compatibility with the latest SQL Server Enterprise Edition.
Designed for migrating on-premises workloads with minimal changes. Offers isolation with native VNet support.
-
SQL Server on Azure Virtual Machines (IaaS):
Lets you run SQL Server inside a fully managed VM. Provides full control over OS and SQL,
but requires you to manage most database administration tasks.
Best Practices for Azure SQL
Performance Optimization
- Choose the right service tier (General Purpose, Business Critical, Hyperscale).
- Use elastic pools for SaaS or multi-database environments with unpredictable usage.
- Enable auto-tuning for query performance and index management.
- Monitor performance using Azure Monitor, Query Performance Insight, and Database Watcher.
- Implement retry logic to handle transient failures gracefully.
Security
- Use Microsoft Entra ID (formerly Azure AD) for authentication.
- Apply network security: VNets, private endpoints, NSGs, and firewall rules.
- Enable Transparent Data Encryption (TDE) and Always Encrypted for sensitive data.
- Turn on Microsoft Defender for SQL to detect threats and vulnerabilities.
- Enable auditing for compliance and anomaly detection.
Cost Optimization
- Right-size resources and scale up/down as needed.
- Use serverless compute tier for variable workloads.
- Leverage Azure Hybrid Benefit to reuse existing SQL Server licenses.
- Consider reserved capacity for predictable workloads to save costs.
Best Use Cases
For Azure SQL Database
- Cloud-native applications requiring high availability and minimal admin effort.
- Variable workloads with elastic pools for SaaS applications.
- Cost-effective development and testing with serverless options.
For Azure SQL Managed Instance
- Lift-and-shift migration of on-premises SQL Server workloads.
- Consolidating multiple SQL Server instances into a managed pool.
- Applications requiring high security and isolation with VNet support.
For SQL Server on Azure VMs
- Scenarios needing full administrative control over OS and SQL Server.
- Lift-and-shift migrations requiring 100% SQL Server compatibility.
- Legacy deployments with custom hardware or configurations.
