SQL Server 2019 Components and Features by OS

SQL Server 2019, currently in preview, brings the database feature set of the Windows and Linux version closer to parity, but going forward, many new features will be OS specific and it is unlikely that the two versions will ever be the same. The chart compares components and key features available on Windows and Linux versions. New capabilities planned for SQL Server 2019 are shown with an asterisk(*).

SQL Server on Linux is not a shimmed or virtual implementation of SQL Server for Windows running on Linux, but rather it is the core product running natively on a Linux distribution. This is possible because SQL Server runs on a platform abstraction layer, called SQLPAL, which communicates between the core SQL Server product and the underlying OS, whether Windows or Linux.

The abstraction layer allowed Microsoft to quickly bring the product to Linux; however, the Linux OS is different from Windows, and there have been some modifications and additions to the product to accommodate OS-specific characteristics. For example, file path structures are different, and failover features require extra Linux components to work properly.