@Override
  public boolean canRunOptimizedCalculation(int rowNum, Range range) {
    return true;
  }
This class evaluates count(*) for a PTF group.

Count all rows of the group.  No input column/expression.
ql/src/java/org/apache/hadoop/hive/ql/exec/vector/ptf/VectorPTFEvaluatorCountStar.java