code: @Override
    public SqlResult sql(String command, Integer maxRows, DataSourceDescriptor dataSource) throws DDFException {
      // TODO: handle other dataSources and dataFormats
      DataFrame  rdd = this.getHiveContext().sql(command);
      Schema schema = SparkUtils.schemaFromDataFrame(rdd);
  
      String[] strResult = SparkUtils.df2txt(rdd, "\t");
      return new SqlResult(schema,Arrays.asList(strResult));
    }
docs: TODO SparkSql