def main(args: Array[String]): Unit = {
    printf("Infering schema from %s\n", wiki_pages)
    val (sc, conf) = Util.createSpark();
    {
      // from https://github.com/Teradata/kylo/raw/master/samples/sample-data/parquet/userdata1.parquet
      val df = sc.read.parquet("swift://wiki.OVH/userdata1.parquet")
      printf("There are %d items\n", df.count())
      df.show()
      //df.repartition(5).write.mode("overwrite").parquet("swift://wiki.OVH/userdata1-rewrite.parquet")
      //df.write.mode("overwrite").parquet("swift://wiki.OVH/userdata1-rewrite.parquet")
      df.write.mode("overwrite").format("parquet").save("swift://wiki.OVH/userdata1-rewrite.parquet")
    }
    {
      val df = sc.read.parquet("swift://wiki.OVH/userdata1-rewrite.parquet")
      printf("There are %d items\n", df.count())
      df.show()
    }
}