UDFs in PySpark: When to Use Them, Why They Can Be Slow, and Better Alternatives
How User-Defined Functions work inside Spark—and why experienced PySpark engineers treat them carefully You have a DataFrame. You need to apply a custom transformation. So you write a Python function: Then you turn it into a UDF: It works. But there is an important question: Should you actually use a UDF? In PySpark, the answer … Read more