@Override
  public void write(DataOutput output) throws IOException {
    String partitionInfoString = HCatUtil.serialize(partitionInfo);

    // write partitionInfo into output
    WritableUtils.writeString(output, partitionInfoString);

    WritableUtils.writeString(output, baseMapRedSplit.getClass().getName());
    Writable baseSplitWritable = (Writable) baseMapRedSplit;
    //write  baseSplit into output
    baseSplitWritable.write(output);
  }
Gets the table schema.
@return the table schema
hcatalog/core/src/main/java/org/apache/hive/hcatalog/mapreduce/HCatSplit.java