Apache Spark 面试题与答案

Question: Explain the difference between Spark transformations and actions.

Answer: Transformations are operations that create a new RDD, while actions are operations that return a value to the driver program or write data to an external storage system.

Example:

val mappedRDD = inputRDD.map(x => x * 2)
val result = mappedRDD.reduce((x, y) => x + y)