According to Microsoft’s documentation, “Database compatibility level … allow[s] the SQL Server Database Engine to be upgraded while keeping the same functional status for connecting applications by maintaining the same pre-upgrade database compatibility level.”
But these days, the “functional status” of a database at a given compatibility level differs depending on whether you’re using SQL Server, Azure SQL Managed Instance, or Azure SQL Database – and in the hosted versions it may change anytime without notice. Surprise, your database behaves differently now!
The whole concept is breaking down, and this is bad news for users of both managed services and the boxed product.
Read on to learn more about the issue.