问：如何从年-月-日分区列列表中提取最近/最近的分区
1） 我需要提取最新的分区。
2） 我需要分别计算年、月和日，这样我就可以在另一个Dataframe中使用它作为变量。
因为最终目标是获得最新/最近的分区。。。你可以使用jodaapi DateTime 通过排序 isAfter 获取最新的分区，如下面的示例所示。
之后 spark.sql(s"show Partitions $yourtablename") 你会得到一个Dataframe collect 因为它的小数据没有问题。
一旦你收集了Dataframe分区，你就会得到这样一个数组

val x = Array(
    "year=2019/month=1/day=21",
    "year=2019/month=1/day=22",
    "year=2019/month=1/day=23",
    "year=2019/month=1/day=24",
    "year=2019/month=1/day=25",
    "year=2019/month=1/day=26",
    "year=2019/month=2/day=27"
  )
  val finalPartitions = listKeys()

  import org.joda.time.DateTime

  def listKeys(): Seq[Map[String, DateTime]] = {
    val keys: Seq[DateTime] = x.map(row => {
      println(s" Identified Key: ${row.toString()}")
      DateTime.parse(row.replaceAll("/", "")
        .replaceAll("year=", "")
        .replaceAll("month=", "-")
        .replaceAll("day=", "-")
      )
    })
      .toSeq
    println(keys)
    println(s"Fetched ${keys.size} ")
    val myPartitions: Seq[Map[String, DateTime]] = keys.map(key => Map("businessdate" -> key))

    myPartitions
  }
  val mapWithMostRecentBusinessDate = finalPartitions.sortWith(
    (a, b) => a("businessdate").isAfter(b("businessdate"))
  ).head

  println(mapWithMostRecentBusinessDate)
  val latest: Option[DateTime] = mapWithMostRecentBusinessDate.get("businessdate")
  val year = latest.get.getYear();
  val month = latest.get.getMonthOfYear();
  val day = latest.get.getDayOfMonth();
  println("latest year "+ year + "  latest month " + month + "  latest day  " + day)

最终结果：即你最近的约会是 2019-02-27 现在基于此，您可以以优化的方式查询配置单元数据。

Identified Key: year=2019/month=1/day=22
 Identified Key: year=2019/month=1/day=23
 Identified Key: year=2019/month=1/day=24
 Identified Key: year=2019/month=1/day=25
 Identified Key: year=2019/month=1/day=26
 Identified Key: year=2019/month=2/day=27
WrappedArray(2019-01-21T00:00:00.000-06:00, 2019-01-22T00:00:00.000-06:00, 2019-01-23T00:00:00.000-06:00, 2019-01-24T00:00:00.000-06:00, 2019-01-25T00:00:00.000-06:00, 2019-01-26T00:00:00.000-06:00, 2019-02-27T00:00:00.000-06:00)
Fetched 7 
Map(businessdate -> 2019-02-27T00:00:00.000-06:00)
latest year 2019  latest month 2  latest day  27