@Override
  public void readFields(DataInput dataInput) throws IOException {
    writeId = dataInput.readLong();
    bucketId = dataInput.readInt();
    rowId = dataInput.readLong();
  }
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