The code block displayed below contains an error. The code block should return a copy of DataFrame transactionsDf where the name of column transactionId has been changed to transactionNumber. Find the error.
Code block:
transactionsDf.withColumn("transactionNumber", "transactionId")

• A. The method withColumn should be replaced by method withColumnRenamed and the arguments to the method need to be reordered.
• B. The arguments to the withColumn method need to be reordered and the copy() operator should be appended to the code block to ensure a copy is returned.
• C. Each column name needs to be wrapped in the col() method and method withColumn should be replaced by method withColumnRenamed.
• D. The copy() operator should be appended to the code block to ensure a copy is returned.
• E. The arguments to the withColumn method need to be reordered.

Which of the following code blocks returns a copy of DataFrame transactionsDf that only includes columns transactionId, storeId, productId and f?
Sample of DataFrame transactionsDf:
1.+-------------+---------+-----+-------+---------+----+
2.|transactionId|predError|value|storeId|productId| f|
3.+-------------+---------+-----+-------+---------+----+
4.| 1| 3| 4| 25| 1|null|
5.| 2| 6| 7| 2| 2|null|
6.| 3| 3| null| 25| 3|null|
7.+-------------+---------+-----+-------+---------+----+

• A. transactionsDf.drop(col("value"), col("predError"))
• B. transactionsDf.drop(["predError", "value"])
• C. transactionsDf.drop("predError", "value")
• D. transactionsDf.drop([col("predError"), col("value")])
• E. transactionsDf.drop(value, predError)

Which of the following statements about executors is correct?

• A. Executors store data in memory only.
• B. Executors are launched by the driver.
• C. An executor can serve multiple applications.
• D. Executors stop upon application completion by default.
• E. Each node hosts a single executor.

Which of the following describes the difference between client and cluster execution modes?

• A. In cluster mode, the driver runs on the worker nodes, while the client mode runs the driver on the client machine.
• B. In cluster mode, the driver runs on the edge node, while the client mode runs the driver in a worker node.
• C. In cluster mode, each node will launch its own executor, while in client mode, executors will exclusively run on the client machine.
• D. In cluster mode, the driver runs on the master node, while in client mode, the driver runs on a virtual machine in the cloud.
• E. In client mode, the cluster manager runs on the same host as the driver, while in cluster mode, the cluster manager runs on a separate node.

Which of the following code blocks returns a new DataFrame with only columns predError and values of every second row of DataFrame transactionsDf?
Entire DataFrame transactionsDf:
1.+-------------+---------+-----+-------+---------+----+
2.|transactionId|predError|value|storeId|productId| f|
3.+-------------+---------+-----+-------+---------+----+
4.| 1| 3| 4| 25| 1|null|
5.| 2| 6| 7| 2| 2|null|
6.| 3| 3| null| 25| 3|null|
7.| 4| null| null| 3| 2|null|
8.| 5| null| null| null| 2|null|
9.| 6| 3| 2| 25| 2|null|
10.+-------------+---------+-----+-------+---------+----+

• A. transactionsDf.select(col("transactionId").isin([3,4,6]), "predError", "value")
• B. transactionsDf.filter(col(transactionId).isin([3,4,6]))
• C. 1.transactionsDf.createOrReplaceTempView("transactionsDf")
  2.spark.sql("FROM transactionsDf SELECT predError, value WHERE transactionId % 2 = 2")
• D. transactionsDf.filter(col("transactionId").isin([3,4,6])).select([predError, value])
• E. transactionsDf.filter(col("transactionId") % 2 == 0).select("predError", "value") (Correct)
• F. transactionsDf.filter("transactionId" % 2 == 0).select("predError", "value")