Exam Certified Associate Developer for Apache Spark topic 1 question 52 discussion

D. result_df = df1.join(df2, on="id", how="outer")

D is correct. There is no exists outerJoin() operation in pyspark.

The correct answer is C - DataFrame.outerJoin(). The outer join operation can be performed by specifying the join type as "outer" when calling the outerJoin() function on a DataFrame. The join() function in Spark only performs an inner join, while the merge() function is not a valid function in Spark SQL. The crossJoin() function performs a Cartesian product between two DataFrames, which is not an outer join.