Azure SQL Database Reference Overview

Introduction to Azure SQL Database

Azure SQL Database is a fully managed Platform as a Service (PaaS) database engine that is built on the SQL Server engine. It is a cloud-based relational database service that provides a scalable, high-performance, and highly available solution for modern application development.

Azure SQL Database offers a unique proposition for developers and administrators: you can use the latest stable version of Microsoft SQL Server, and it handles most of the database management functions without requiring you to have deep infrastructure expertise. This allows you to focus on your application and its data, rather than on database administration.

Key benefits include:

• High Availability and Durability: Built-in redundancy and automated backups ensure your data is safe and accessible.
• Scalability: Easily scale your database resources up or down based on demand.
• Performance: Optimized for high performance with various service tiers and compute options.
• Security: Robust security features including encryption, threat detection, and access control.
• Intelligent Capabilities: Leverages machine learning for performance tuning, security recommendations, and anomaly detection.

Key Concepts

Understanding these core concepts is essential for effectively using Azure SQL Database:

Database Editions and Service Tiers

Azure SQL Database offers different deployment options and service tiers to meet varying needs:

• Single Database: An isolated database with its own set of resources managed via a logical server.
• Elastic Pool: A collection of single databases with shared resources, ideal for workloads with unpredictable usage patterns.
• Managed Instance: A fully managed SQL Server instance hosted in Azure, offering near 100% compatibility with on-premises SQL Server.

Within these options, you choose service tiers like:

• General Purpose: Balanced compute and storage for common transactional workloads.
• Business Critical: High performance with low latency, utilizing in-memory technologies and multiple replicas.
• Hyperscale: Scalable to very large databases with rapid scaling capabilities.

Logical Server

A logical server is a management construct in Azure that acts as a central administrative point for a collection of databases. It contains databases that are independent and can be moved between servers. Each logical server has a unique name, and it contains server-level firewall rules, authentication, and management policies.

DTUs and vCores

Resource provisioning is managed through either:

• Database Transaction Units (DTUs): A bundled measure of CPU, memory, and I/O.
• vCores: A more transparent model that allows you to choose the number of virtual cores, memory, and storage.

The vCore model is generally recommended for new deployments.

Transparent Data Encryption (TDE)

TDE encrypts data at rest, including data and log files, protecting sensitive information from unauthorized access.

Azure Hybrid Benefit

Leverage your existing on-premises SQL Server licenses with Software Assurance to save costs on Azure SQL Database.

Getting Started with Azure SQL Database

Here's a typical workflow to get started:

1. Create a Logical Server: Provision a logical server in the Azure portal or using Azure CLI.
2. Create a Database: Within the logical server, create a new database, selecting your desired service tier and performance level.
3. Configure Firewall Rules: Set up server-level and database-level firewall rules to control access.
4. Connect to Your Database: Use SQL Server Management Studio (SSMS), Azure Data Studio, or other compatible tools to connect.
5. Develop Your Application: Start building your applications to interact with the database using standard SQL and relevant SDKs.

For detailed guidance and best practices, refer to the subsequent sections of this reference.