private boolean compareLongColumnVector(LongColumnVector cv1, LongColumnVector cv2) {
    int length1 = cv1.vector.length;
    int length2 = cv2.vector.length;
    if (length1 == length2) {
      for (int i = 0; i < length1; i++) {
        if (columnVectorsDifferNullForSameIndex(cv1, cv2, i)) {
          return false;
        }
        if (!cv1.isNull[i] && !cv2.isNull[i] && cv1.vector[i] != cv2.vector[i]) {
          return false;
        }
      }
    } else {
      return false;
    }
    return true;
  }
Get the child ColumnVector of ListColumnVector
ql/src/java/org/apache/hadoop/hive/ql/io/parquet/vector/VectorizedListColumnReader.java