@Override
  public boolean isDeterministic() {
    boolean result = FunctionRegistry.isDeterministic(genericUDF);
    for (ExprNodeEvaluator child : children) {
      result = result && child.isDeterministic();
    }
    return result;
  }
Class to allow deferred evaluation for GenericUDF.
ql/src/java/org/apache/hadoop/hive/ql/exec/ExprNodeGenericFuncEvaluator.java