@Override public String toString() {
    return "DruidWritable{"
        + "value="
        + value
        + ", compactedValue="
        + compactedValue
        + ", compacted="
        + compacted
        + '}';
  }
list of values in a compacted form, Serializer/Deserializer needs to agree on the order of values.
This is only used when the result is compacted.
druid-handler/src/java/org/apache/hadoop/hive/druid/serde/DruidWritable.java