public Class<? extends OutputFormat> getOutputFileFormatClass() {
    if (outputFileFormatClass == null && tableDesc != null) {
      setOutputFileFormatClass(tableDesc.getOutputFileFormatClass());
    }
    return outputFileFormatClass;
  }
Return a deserializer object corresponding to the partitionDesc.
ql/src/java/org/apache/hadoop/hive/ql/plan/PartitionDesc.java