Last week at Microsoft Ignite, Microsoft introduced the public preview of the Managed Instances for Azure SQL Database. This is a new product that is a hybrid between running fully platform as a service (PaaS, in this case being Azure SQL Database) or infrastructure as a service (IaaS, or in this case SQL Server running on a VM). It has built-in support for cross-database queries and basically looks and feels just like your on-premises SQL Server. Probably my favorite part is the ability to just migrate a backup directly into the service from Azure Blob storage. There is also the benefit of being able to bring your own license to reduce some of the costs. Additionally, you can have much larger databases, up to 35 TB.

Managed instances will be a good fit for you if:

You don’t own your code and need it to work with SQL Server

Your application makes a lot of cross database calls

You need to be able to migrate with near zero downtime

You have large databases that are not a good fit for the Azure SQL Database model

I think Azure SQL DB and Managed Instances will co-exist for the foreseeable future as each platform has a good use case.