Azure SQL Database - Managed Cloud Database

What is Azure SQL Database?

Azure SQL Database is Microsoft’s fully managed relational cloud database built on the SQL Server engine. The service provides built-in intelligence with automatic tuning, a serverless compute mode for variable workloads, and continuously updated SQL Server features without manual maintenance or patching.

At its core, Azure SQL Database is a platform-as-a-service (PaaS) offering that fully abstracts infrastructure management such as backups, patching, and high availability. You get a SQL Server-compatible database with T-SQL support, without managing VMs, operating system updates, or storage configuration.

Azure SQL Database is available in several service tiers: General Purpose for most workloads with a balanced ratio of performance and cost, Business Critical for the lowest latency via local SSD storage and a free readable replica, and Hyperscale with decoupled compute and storage for very large and fast-growing databases. Microsoft now positions Hyperscale as the recommended default tier for new and modernizing OLTP and HTAP workloads. In addition, the serverless compute mode (within the General Purpose tier) is available for workloads with highly variable usage. All tiers support either vCore-based or DTU-based pricing.

Core Features

• General Purpose: Storage decoupled from compute via Azure Blob Storage, standard SLA, latency in the low single-digit to low double-digit millisecond range.
• Business Critical: An integrated cluster of database engine processes with locally attached SSD storage, a primary replica plus multiple secondary replicas, and a free readable replica for reporting.
• Hyperscale: Cloud-native architecture with decoupled compute and storage, a configurable number of high-availability replicas (0-4), and near-instant backups via storage snapshots.
• Serverless: Automatic pausing when idle and automatic scaling of compute resources between configurable minimum and maximum values.
• Security: Always Encrypted, Transparent Data Encryption, dynamic data masking, row-level security.
• High availability and disaster recovery: Zone redundancy, active geo-replication, and auto-failover groups for automated cross-region failover.

Typical Use Cases

SaaS Applications with Elastic Pools

SaaS providers host many customer databases in elastic pools that dynamically share compute and storage resources across multiple databases. Each customer gets an isolated database, while resources are shared across the pool, saving costs for variable load profiles.

Mission-Critical Line-of-Business Apps

Enterprise applications such as ERP, finance, or inventory systems use the Business Critical tier for low latency and the built-in readable replica for reporting workloads without affecting the primary system.

Variable Workloads with Serverless

Development and test databases, as well as applications with sporadic access patterns, use serverless mode. The database automatically pauses when idle and automatically scales compute resources based on load.

Data Warehousing with Hyperscale

Analytical workloads with large data volumes use Hyperscale to grow without significant performance degradation. Hyperscale separates compute and storage, scales storage automatically, and offers multiple read replicas for parallel queries.

Migrated SQL Server Workloads

Organizations migrate on-premises SQL Server instances to Azure SQL Database using the Azure Database Migration Service. Compatibility with T-SQL, stored procedures, triggers, and views enables migrations with low adaptation effort. Azure Hybrid Benefit can reduce license costs for existing SQL Server licenses.

Benefits

• Fully managed database without operating your own infrastructure.
• Automatic tuning and Query Performance Insights for continuous optimization.
• Flexible pricing models (vCore, DTU, serverless) for different workload profiles.
• Built-in high availability and disaster recovery capabilities.
• Close integration with the Azure ecosystem (Entra ID, Key Vault, Private Link).

Frequently Asked Questions about Azure SQL Database

What is the difference between General Purpose and Business Critical?

General Purpose uses decoupled remote storage with standard latency and suits most workloads. Business Critical uses locally attached SSD storage with significantly lower latency and includes a free readable replica, at a noticeably higher cost than General Purpose.

What is Hyperscale and which workloads is it suited for?

Hyperscale is a cloud-native architecture that separates compute and storage. Storage grows automatically with the database, backups happen nearly instantly via storage snapshots, and multiple read replicas can be added. Microsoft now recommends Hyperscale as the default choice for new OLTP and HTAP workloads, not just for very large databases.

What is an elastic pool and when should I use it?

Elastic pools share vCores and storage across multiple databases. They suit scenarios with many databases and variable load profiles, such as one database per SaaS customer, since not every database needs to be individually provisioned for peak load.

How do automatic backups work?

Azure SQL Database automatically creates full, differential, and transaction log backups. Point-in-time restore allows recovery to any point within the configured retention period of 1 to 35 days. For longer retention, long-term retention with weekly, monthly, or yearly backups is available for up to 10 years.

Can I run Azure SQL Database inside my own VNet?

Azure SQL Database runs in Microsoft’s multi-tenant infrastructure rather than directly inside your own VNet. For full VNet integration with private IP addresses, Azure SQL Managed Instance is better suited. SQL Database does offer private endpoints, providing a private IP address inside your own VNet with traffic routed over the Microsoft backbone without public internet exposure.

What does Azure SQL Database cost?

Costs depend on the chosen tier, the number of vCores or DTUs, the hardware configuration, and the region. Serverless is billed based on actual compute time used, while provisioned compute is billed for fixed allocated resources. Azure Hybrid Benefit and reserved instances can reduce costs for existing SQL Server licenses or long-term usage. Exact prices are available on the official Azure pricing page.

Is Azure SQL Database GDPR compliant?

Yes, Azure SQL Database can be operated in compliance with GDPR when European Azure regions are chosen. Data does not leave the selected region unless geo-replication to another region is explicitly configured. Microsoft provides data processing agreements under Art. 28 GDPR, along with features like Always Encrypted and Transparent Data Encryption for additional data security.

Azure SQL Database vs. Alternatives

When choosing a cloud solution, the question of alternatives often arises. Azure SQL Database competes with comparable services from other cloud providers:

• AWS: RDS for SQL Server, Aurora (PostgreSQL/MySQL-compatible)
• Google Cloud: Cloud SQL, AlloyDB (PostgreSQL-compatible)

While functionality is often similar, services differ in pricing models, regional availability, and integration ecosystems. Azure SQL Database excels particularly for customers with a Microsoft stack, through SQL Server compatibility, Azure Hybrid Benefit for existing licenses, and deep integration with Azure services.

Integration with innFactory

As a Microsoft Solutions Partner, innFactory supports you with architecture and migration to Azure SQL Database. We help with tier selection, performance tuning, cost optimization, and hybrid scenarios.

Contact us for a non-binding consultation on Azure SQL Database and cloud database strategies.