protected String getLongValueParamString(int typeNum, long value) {
    return "val " + value + ":" + getParamTypeString(typeNum);
  }
Evaluate the child expressions on the given input batch.
@param vrg {@link VectorizedRowBatch}
ql/src/java/org/apache/hadoop/hive/ql/exec/vector/expressions/VectorExpression.java