SQL Server is a relational database management system developed by Microsoft. Migrating an on-premises SQL Server to Azure involves moving the database, its data, and potentially the application to Azure's cloud platform. This migration can be achieved through various methods, including using Azure Database Migration Service (DMS), Azure SQL Migration extension, or by leveraging the SQL Server's native backup and restore features.
Why we may have to migrate on-premises SQL Server database to Azure SQL Database (PaaS—Platform as a Service)?
Microsoft’s enabling functions and cloud offerings have many advantages with Azure SQL Database that runs as a PaaS. On a high level, for instance, there is no need for you to create VMs or install the Windows Server operating system or SQL Server. They are all simply available to use. All you have to do is log into the Azure portal and pick the size and configuration that fits your needs.
Note: The PaaS offering from Microsoft provides you with everything required to support database services. Microsoft owns more than half of the administration overhead, which includes patching, software updates, system maintenance, etc. However, it is important to understand the underlying database service implications of this model. Azure SQL Database doesn’t in-house full feature parity when compared to the on-premise database versions of SQL Server like SQL Server 2014, SQL Server 2016, and SQL server 2017.