Spark Certification

Hello All, I am planning on taking Spark Certification and I was wondering If one has to be well equipped with MLib & GraphX as well or not ? Please advise Thanks

withColumn

I was trying to append a Column to a dataframe df2 by using 'withColumn'(as shown below), can anyone help me understand what went wrong? scala> case class Sharath(name1: String, age1: Long) defined class Sharath scala> val df1 = Seq(Sharath("Sharath", 29)).toDF() df1: