@Override
    public int compareTo(Object arg0) {
      throw new RuntimeException("compareTo not supported in class "
          + this.getClass().getName());
    }
ValueBuffer is the value of each record in RCFile. Its on-disk layout is as
below:
<ul>
<li>Compressed or plain data of [column_1_row_1_value,
column_1_row_2_value,....]</li>
<li>Compressed or plain data of [column_2_row_1_value,
column_2_row_2_value,....]</li>
</ul>
ql/src/java/org/apache/hadoop/hive/ql/io/RCFile.java