Exam Certified Associate Developer for Apache Spark topic 1 question 7 discussion

E is correct.

The correct answer is E. By default, DataFrames will be split into 200 unique partitions when data is being shuffled. Explanation: The spark.sql.shuffle.partitions configuration parameter in Spark determines the number of partitions to use when shuffling data. When a shuffle operation occurs, such as during DataFrame joins or aggregations, data needs to be redistributed across partitions based on a specific key. The spark.sql.shuffle.partitions value defines the default number of partitions to be used during such shuffling operations.

E. By default, DataFrames will be split into 200 unique partitions when data is being shuffled. The spark.sql.shuffle.partitions configuration parameter determines the number of partitions that are used when shuffling data for joins or aggregations. The default value is 200, which means that by default, when a shuffle operation occurs, the data will be divided into 200 partitions. This allows the tasks to be distributed across the cluster and processed in parallel, improving performance. However, the optimal number of shuffle partitions depends on the specific details of your cluster and data. If the number is too small, then each partition will be large, and the tasks may take a long time to run. If the number is too large, then there will be many small tasks, and the overhead of scheduling and processing all these tasks can degrade performance. Therefore, tuning this parameter to match your specific use case can help optimize the performance of your Spark applications.