Which method would be ineffective for calculating min, max, mean, and standard deviation for data in a Spark DataFrame?

Utilizing df.explain().show() is ineffective for calculating min, max, mean, and standard deviation because this method is primarily used for understanding the execution plan of a DataFrame operation rather than performing data computations. The df.explain() method provides insights into the logical and physical plans that Spark uses to execute operations on the DataFrame, which can help in optimizing queries and understanding how Spark processes the data. However, it does not perform any statistical calculations or computations on the DataFrame itself.

In contrast, using statistical functions in PySpark, applying summary statistics methods, and executing aggregate functions are designed specifically for performing such calculations. These methods allow for direct computation of various statistical measures, making them effective for gathering insights from the data within a Spark DataFrame.