public static StructObjectInspector getStandardStructOI(RowResolver rr) {
    StructObjectInspector oi;
    List<ColumnInfo> colLists = rr.getColumnInfos();
    List<String> structFieldNames = new ArrayList<String>();
    List<ObjectInspector> structFieldObjectInspectors = new ArrayList<ObjectInspector>();
    for (ColumnInfo columnInfo : colLists) {
      String colName = columnInfo.getInternalName();
      ObjectInspector colOI = columnInfo.getObjectInspector();
      structFieldNames.add(colName);
      structFieldObjectInspectors.add(colOI);
    }
    oi = ObjectInspectorFactory.getStandardStructObjectInspector(structFieldNames,
        structFieldObjectInspectors);
    return oi;

  }
For each column on the input RR, construct a StructField for it
OI is constructed using the list of input column names and
their corresponding OIs.

@param rr
@return
ql/src/java/org/apache/hadoop/hive/ql/parse/PTFTranslator.java