@Override
  public Operator<? extends OperatorDesc> clone()
    throws CloneNotSupportedException {
    TableScanOperator ts = (TableScanOperator) super.clone();
    ts.setNeededColumnIDs(new ArrayList<Integer>(getNeededColumnIDs()));
    ts.setNeededColumns(new ArrayList<String>(getNeededColumns()));
    ts.setReferencedColumns(new ArrayList<String>(getReferencedColumns()));
    return ts;
  }
The operator name for this operator type. This is used to construct the
rule for an operator

@return the operator name
ql/src/java/org/apache/hadoop/hive/ql/exec/TableScanOperator.java