Online Access Free Associate-Developer-Apache-Spark Practice Test

Which of the following code blocks returns all unique values of column storeId in DataFrame transactionsDf?

• A.transactionsDf.filter("storeId").distinct()
• B.transactionsDf.select("storeId").distinct()
  (Correct)
• C.transactionsDf.distinct("storeId")
• D.transactionsDf.select(col("storeId").distinct())
• E.transactionsDf["storeId"].distinct()

Which of the following statements about Spark's execution hierarchy is correct?

• A.In Spark's execution hierarchy, a job may reach over multiple stage boundaries.
• B.In Spark's execution hierarchy, a stage comprises multiple jobs.
• C.In Spark's execution hierarchy, tasks are one layer above slots.
• D.In Spark's execution hierarchy, executors are the smallest unit.
• E.In Spark's execution hierarchy, manifests are one layer above jobs.

Which of the following code blocks returns DataFrame transactionsDf sorted in descending order by column predError, showing missing values last?

• A.transactionsDf.sort(asc_nulls_last("predError"))
• B.transactionsDf.orderBy("predError").desc_nulls_last()
• C.transactionsDf.orderBy("predError").asc_nulls_last()
• D.transactionsDf.desc_nulls_last("predError")
• E.transactionsDf.sort("predError", ascending=False)

Which of the following DataFrame operators is never classified as a wide transformation?

• A.DataFrame.aggregate()
• B.DataFrame.join()
• C.DataFrame.sort()
• D.DataFrame.repartition()
• E.DataFrame.select()

The code block displayed below contains an error. The code block should arrange the rows of DataFrame transactionsDf using information from two columns in an ordered fashion, arranging first by column value, showing smaller numbers at the top and greater numbers at the bottom, and then by column predError, for which all values should be arranged in the inverse way of the order of items in column value. Find the error.
Code block:
transactionsDf.orderBy('value', asc_nulls_first(col('predError')))

• A.Two orderBy statements with calls to the individual columns should be chained, instead of having both columns in one orderBy statement.
• B.Column predError should be sorted by desc_nulls_first() instead.
• C.Column value should be wrapped by the col() operator.
• D.Instead of orderBy, sort should be used.
• E.Column predError should be sorted in a descending way, putting nulls last.