Azure SQL Database Migration

Comprehensive guides and tools for migrating your databases to Azure SQL Database.

Migrate to Azure SQL Database

Azure SQL Database offers 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.

This documentation provides resources and guidance for migrating your existing SQL Server databases, or other relational databases, to Azure SQL Database. We cover various migration strategies, tools, and best practices to ensure a smooth and successful transition.

Migration Overview

Migrating to Azure SQL Database involves several key phases: discovery, assessment, planning, migration execution, and optimization. Each phase has specific tasks and considerations to ensure data integrity and minimal downtime.

Azure SQL Database supports a variety of workloads, from small databases to large enterprise-scale applications. The migration approach will depend on factors such as your source database type, size, complexity, and acceptable downtime.

Migration Methods

We support multiple migration methods to suit different scenarios:

  • Online Migration: Minimizes downtime by allowing applications to continue running against the source database during the migration process. This is ideal for critical applications where downtime is not an option.
  • Offline Migration: Requires a period of downtime for the application while the database is migrated. This is simpler to implement and can be suitable for non-critical applications or during planned maintenance windows.

Tools & Services for Migration

Microsoft provides a robust set of tools and services to facilitate your migration:

  • Azure Migrate: A centralized hub for discovering, assessing, and migrating on-premises applications and databases to Azure.
  • Azure Database Migration Service (DMS): A fully managed service designed to enable seamless migrations from multiple database sources to Azure data platforms with minimal downtime.
  • SQL Server Management Studio (SSMS): Provides a graphical interface for migrating databases using the "Generate Scripts" or "Deploy Database to Microsoft Azure SQL Database" wizards.
  • Data Migration Assistant (DMA): An application that provides recommendations on database migration and can migrate schema and data from SQL Server to Azure SQL Database.

Choose the tool that best fits your migration strategy and technical requirements.

Database Assessment

Before migrating, it's crucial to assess your source database for compatibility issues and feature parity with Azure SQL Database. This helps identify potential challenges early on.

Use tools like Data Migration Assistant (DMA) or Azure Migrate's assessment features to:

  • Identify compatibility issues and unsupported features.
  • Receive recommendations for performance improvements.
  • Estimate the effort and resources required for migration.

Performing an Offline Migration

An offline migration typically involves the following steps:

1

Backup the Source Database

Ensure you have a recent, verified backup of your source database.

2

Migrate Schema and Data

Use tools like SSMS or DMA to generate scripts for your schema and data, and then deploy them to a newly created Azure SQL Database instance.

3

Reconfigure Applications

Update your application connection strings to point to the Azure SQL Database.

4

Test and Validate

Thoroughly test your application to ensure everything functions as expected.

Performing an Online Migration

Online migrations are more complex and often leverage Azure Database Migration Service (DMS):

1

Set up DMS

Create an Azure Database Migration Service instance in your Azure subscription.

2

Configure Migration Project

Define your source and target database details, select databases, and configure migration settings.

3

Start Data Synchronization

DMS will perform an initial data load and then continuously synchronize changes from the source to the target database.

4

Perform Cutover

During a brief downtime window, stop application traffic, ensure all pending changes are synchronized, and then perform the cutover to the Azure SQL Database.

Post-Migration Activities

After a successful migration, focus on optimizing your database and application performance in Azure:

  • Monitor performance metrics.
  • Tune queries and indexes.
  • Configure automatic backups and disaster recovery options.
  • Update any application logic that relies on specific SQL Server features not available in Azure SQL Database.

Migration Best Practices

  • Thorough Assessment: Always start with a comprehensive assessment.
  • Test Extensively: Perform multiple test migrations and application validation.
  • Minimize Downtime: Plan your migration window carefully and consider online migration for critical systems.
  • Security First: Implement appropriate security measures for your Azure SQL Database.
  • Monitor and Optimize: Continuously monitor performance and optimize post-migration.
Start Your Migration