private boolean compareBytesColumnVector(BytesColumnVector cv1, BytesColumnVector cv2) {
    int length1 = cv1.vector.length;
    int length2 = cv2.vector.length;
    if (length1 != length2) {
      return false;
    }

    for (int i = 0; i < length1; i++) {
      // check for different nulls
      if (columnVectorsDifferNullForSameIndex(cv1, cv2, i)) {
        return false;
      }

      // if they are both null, continue
      if (cv1.isNull[i] && cv2.isNull[i]) {
        continue;
      }

      // check if value lengths are the same
      int innerLen1 = cv1.vector[i].length;
      int innerLen2 = cv2.vector[i].length;
      if (innerLen1 != innerLen2) {
        return false;
      }

      // compare value stored
      for (int j = 0; j < innerLen1; j++) {
        if (cv1.vector[i][j] != cv2.vector[i][j]) {
          return false;
        }
      }
    }
    return true;
  }
Get the child ColumnVector of ListColumnVector
ql/src/java/org/apache/hadoop/hive/ql/io/parquet/vector/VectorizedListColumnReader.java