As of October 2018, Azure SQL Database Managed Instance is now generally available in the general purpose tier. Business Critical should be available in the near future.
The general purpose tier of Managed Instance being available will now allow businesses to do proof of concepts and be able to elevate those environments to production knowing they are fully supported.
Managed Instance is a new deployment model of Azure SQL Database. Azure SQL Database is built on a database scoped programming model whereas Managed Instance is built on an instance scoped programming model. Azure SQL Database provides database isolation protection which makes it great for applications that leverage a single database. Many software-as-service vendors benefit greatly from this model. Other applications that require multiple databases can’t properly utilize Azure SQL Database due to the database isolation. Azure SQL Database does not support cross-database queries.
With Managed Instance being instance scoped, all the databases on the instance are on the same server and support cross database queries. The goal of Managed Instance is to provide near 100% surface area compatibility with SQL Server. Many of the perceived limitations of Azure SQL Database are supported with Managed Instance. Things like SQL Agent, database mail, service broker, CLR, and more.
If you would like to be in a managed environment and have looked at Azure SQL Database but need more of the look at feel of SQL Server, Managed Instance is likely what you need. If you need help doing a proof of concept or a migration, reach out.
