Databricks Certified Associate Developer for Apache Spark — Question 151

Which of the following operations can be used to perform a left join on two DataFrames?

Answer options

• A. DataFrame.join()
• B. DataFrame.crossJoin()
• C. DataFrame.merge()
• D. DataFrame.leftJoin()
• E. Standalone join() function

Correct answer: A

Explanation

The correct answer is A, as DataFrame.join() is specifically designed to perform join operations including left joins. Options B and D are incorrect because DataFrame.crossJoin() does not perform a left join, and DataFrame.leftJoin() is not a valid method. Option C, DataFrame.merge(), can also perform joins but does not specifically indicate a left join without additional parameters, and option E is not a valid function for DataFrames.