spark-core-aggregateByKey-get-revenue-and-count-per-order-id.scala

val orderItems = sc.textFile("/public/retail_db/order_items")

val orderItemsMap = orderItems.
  map(oi => (oi.split(",")(1).toInt, oi.split(",")(4).toFloat))
  
val revenueAndCountPerOrder = orderItemsMap.
  aggregateByKey((0.0, 0))(
    (agg, ele) => (agg._1 + ele, agg._2 + 1),
    (total, inter) => (total._1 + inter._1, total._2 + inter._2)
  )
  
revenueAndCountPerOrder.
  take(10).
  foreach(println)