Azure SQL Database Architecture

This document provides an in-depth look at the architecture of Azure SQL Database, explaining how it is built on a distributed platform and leverages the capabilities of Azure SQL Managed Instance and SQL Server.

Core Components and Concepts

Azure SQL Database is a fully managed Platform as a Service (PaaS) database engine that handles most database management functions such as upgrading, patching, backups, and high availability without user involvement. It is built on the same engine as SQL Server but runs on a distributed platform.

The Shared Responsibility Model

In Azure SQL Database, Microsoft is responsible for the underlying infrastructure, operating system, and database engine patching and updates. You, as the customer, are responsible for your data and the access to it. This model simplifies database management and allows you to focus on your applications.

The Scale-Out Architecture

Azure SQL Database is designed for massive scale and high availability. It utilizes a sophisticated distributed architecture that separates compute and storage, enabling independent scaling and resilience. Key elements include:

Logical Architecture Diagram

A simplified view of the Azure SQL Database architecture:

Azure SQL Database Architecture Diagram

Note: This is a conceptual diagram. The actual implementation involves numerous redundant systems and services.

Understanding Compute and Storage Separation

One of the fundamental architectural advantages of Azure SQL Database is the separation of compute and storage. This allows for:

Deployment Options

Azure SQL Database offers several deployment options to cater to different needs:

Key Architectural Layers

The Azure SQL Database engine is built on a robust foundation:

High Availability and Disaster Recovery

Azure SQL Database offers built-in high availability and disaster recovery capabilities:

Performance and Scalability

The distributed nature of Azure SQL Database allows for seamless scaling of both performance and storage. You can choose from various service tiers (General Purpose, Business Critical, Hyperscale) and compute sizes to match your workload requirements.