As mentioned in the previous topic, Azure SQL Database is a Massively Parallel Processing (MPP) system. By contrast, a Symmetric Multiprocessing (SMP) system is more like the classic SQL Server that you’re probably familiar with, in that it usually utilizes one large machine, either on-premises on the client, either a physical or virtualized machine. A Massively Parallel Processing (MPP) system, on the other hand, is composed of multiple machines, not just one large machine. Usually these machines will all have a slice of the data from the database, and when a query comes in, the query execution is distributed across each machine to generate the query results you require. When you need to perform query analysis against large datasets, an MPP system scales very well as the amount of data increases.
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