public int delete(long lowerBound, long upperBound) {
    int deletedNumber = 0;
    long maxTime = Long.MIN_VALUE;
    long minTime = Long.MAX_VALUE;
    for (int i = 0; i < rowCount; i++) {
      long time = getTime(i);
      if (time >= lowerBound && time <= upperBound) {
        int originRowIndex = getValueIndex(i);
        if (!isNullValue(originRowIndex)) {
          int arrayIndex = originRowIndex / ARRAY_SIZE;
          int elementIndex = originRowIndex % ARRAY_SIZE;
          markNullValue(arrayIndex, elementIndex);
          deletedNumber++;
        }
      } else {
        maxTime = Math.max(time, maxTime);
        minTime = Math.min(time, minTime);
      }
    }
    return deletedNumber;
  }
Get whether value is null at the given position in TvList.

@param unsortedRowIndex value index
@return boolean
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/utils/datastructure/TVList.java