Microsoft SQL Server, Azure SQL Database, and Azure SQL Data Warehouse: What's the difference?

Microsoft has so many database products with SQL in their names that it's not hard to understand why some people get them confused. Do you know the difference between:

The tl;dr is that SQL Server can be an on-premises enterprise database, Azure SQL Database is a cloud-hosted enterprise database, and Azure SQL Data Warehouse is a cloud-hosted data warehouse. But there's more to the story.

A deeper dive

All of these platforms have some history behind them.

SQL Server was Microsoft's first enterprise database. It debuted in 1989 for OS/2, an ill-fated operating system collaboration between Microsoft and IBM. Microsoft ported SQL Server to Windows NT when that operating system was introduced in 1993. The most current version is SQL Server 2019. It runs atop Windows Server and Linux operating systems, either on local servers or on cloud instances.

On-premises servers were the standard way organizations ran most of their software until about 2006, when Amazon launched Amazon Web Services (AWS) and gave birth to the cloud computing revolution. Amazon began offering a relational database on AWS in 2009. Amazon Relational Database Service (RDS) was a SaaS alternative to local databases like SQL Server, or to running those databases on Amazon Elastic Compute Cloud (EC2). There's a version of RDS for SQL Server.

Meanwhile, Microsoft began working on its own cloud platform, Windows Azure, which it introduced it in 2010. (The company changed the name to Microsoft Azure in 2014.) Along with cloud storage, Microsoft offered a cloud-hosted version of SQL Server that it called SQL Azure, which it renamed Azure SQL Database in 2012. The current version of Azure SQL Database shares the SQL Server 2016 codebase.

Amazon, meanwhile, continued developing its cloud platform. In 2013 it launched Redshift, a column-oriented database designed to support analytics queries. In 2015, Microsoft countered with Azure SQL Data Warehouse, its own enterprise data warehouse.

The competition

Today each of these databases competes against several prominent alternatives:

Microsoft database Comparable products and platforms
On-premises relational database SQL Server Oracle Database, IBM Db2, SAP Sybase ASE, PostgreSQL, MySQL, MariaDB
Cloud RDBMS Azure SQL Database Amazon RDS, Amazon Aurora, Google Cloud SQL, Heroku Postgres, EnterpriseDB Postgres, Oracle Database Cloud Service
Cloud data warehouse Azure SQL Data Warehouse Amazon Redshift, Google BigQuery, Snowflake, IBM Db2 Warehouse on Cloud

Stitch supports Azure SQL Data Warehouse as a destination. Demand for an Azure data warehouse alternative has grown along with the platform's strong and steady growth. Stitch's acquisition by Talend last year, and the close partnership between Talend and Microsoft, also made support for Azure SQL Data Warehouse a natural move.

If you're using Azure SQL Data Warehouse, sign up for Stitch and begin replicating your data sources to your data warehouse in minutes. New users get a free 14-day trial, during which you can move an unlimited amount of data from more than 90 data sources, including popular platforms such as Google Analytics and Google Ads, Shopify, Salesforce, and Stripe.

Image credit: Jason Mrachina, Yiuamwbxn