This tip shows a neat trick with CROSS APPLY that lets your metadata queries ignore columns that don't exist yet.
January 2019
Read a quick overview Scalar UDF Inlining, a long-awaited feature in SQL Server 2019 that will improve the performance of some workloads.
If you use scalar user-defined functions, and can't take advantage of new handling in SQL Server 2019, see some other ways to reduce the impact on performance.