[Spark] join 연산, csv, json, Parquet, ORC
join person = spark.createDataFrame([ (0, "Bill Chambers", 0, [100]), (1, "Matei Zaharia", 1, [500, 250, 100]), (2, "Michael Armbrust", 1, [250, 100])])\ .toDF("id", "name", "graduate_program", "spark_status") graduateProgram = spark.createDataFrame([ (0, "Masters", "School of Information", "UC Berkeley"), (2, "Masters", "EECS", "UC Berkeley"), (1, "Ph.D.", "EECS", "UC Berkeley")])\ .toDF("id", ..