What performance behavior would you expect in SQL Server when you use multiple time functions in a single statement?

In SQL Server, using functions such as GETDATE(), DATEADD, DATEDIFF, or converting datetime to string can make a query non‑sargable, which often forces a full table scan. When multiple time functions appear in a single SELECT or WHERE clause, the optimizer may still push them to the execution plan, but if they are applied to columns, indexes cannot be used, leading to slower execution and higher CPU usage. If the functions are applied to constants, the cost is negligible. The expected behavior is a noticeable slowdown, increased CPU and memory consumption, and potential index scans. To mitigate this, pre‑compute time values, use indexed computed columns, or rewrite the query to use range predicates that allow index seeks. Monitoring the execution plan and adjusting the query can help restore performance.