How to explode columns?

Question

After:

val df = Seq((1, Vector(2, 3, 4)), (1, Vector(2, 3, 4))).toDF(\"Col1\", \"Col2\")

I have this DataFrame in Apache Spark:

Answer 1

Just add on to sgvd's solution:

If the size is not always the same, you can set nElements like this:

val nElements = df.select(size('Col2).as("Col2_count"))
                  .select(max("Col2_count"))
                  .first.getInt(0)