protected int compareToInternal(RecordIdentifier other) {
    if (other == null) {
      return -1;
    }
    if (writeId != other.writeId) {
      return writeId < other.writeId ? -1 : 1;
    }
    if (bucketId != other.bucketId) {
      return bucketId < other.bucketId ? - 1 : 1;
    }
    if (rowId != other.rowId) {
      return rowId < other.rowId ? -1 : 1;
    }
    return 0;
  }
What was the original row id for the last row?
@return the row id
ql/src/java/org/apache/hadoop/hive/ql/io/RecordIdentifier.java