@Override
  public String vectorExpressionParameters() {
    return "val " + org.apache.hadoop.hive.common.type.Date.ofEpochMilli(value.getTime()) + ", " + getColumnParamString(1, inputColumnNum[0]);
  }
Method to evaluate scalar-column operation in vectorized fashion.

@batch a package of rows with each column stored in a vector
ql/src/java/org/apache/hadoop/hive/ql/exec/vector/expressions/DateScalarSubtractDateColumn.java