public void close() {
      for (NonSyncDataOutputBuffer element : loadedColumnsValueBuffer) {
        IOUtils.closeStream(element);
      }
      if (codec != null) {
        IOUtils.closeStream(decompressBuffer);
        if (valDecompressor != null) {
          // Make sure we only return valDecompressor once.
          CodecPool.returnDecompressor(valDecompressor);
          valDecompressor = null;
        }
      }
    }
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