void startPartition() throws HiveException {
      if ( isStreaming() ) {
        tabFn.startPartition();
      } else {
        if ( prev == null || prev.isOutputIterator() ) {
          if ( inputPart == null ) {
            createInputPartition();
          } else {
            inputPart.reset();
          }
        }
      }
      if ( next != null ) {
        next.startPartition();
      }
    }
@return the name of the operator
ql/src/java/org/apache/hadoop/hive/ql/exec/PTFOperator.java