"Scalar UDFs and Row-by-Row Processing"

They can be inlined into execution plans. They run once per row, causing performance issues. They are always executed in parallel. They have no impact on execution plans.

It eliminates the use of UDFs entirely. It allows scalar UDFs to be inlined into execution plans. It executes UDFs in parallel only when called from a SELECT statement. It converts all scalar UDFs into stored procedures.

It improves the performance significantly. It is treated as a non-SARGable expression, impacting query optimization. It allows parallel execution of queries. It does not affect the execution plan at all.

Using multi-statement table-valued functions instead. Implementing cursors to process each row individually. Inlining the expression directly in the query. Relying on heuristic optimizations by SQL Server.