private int getColumnValueCnt(int columnIndex) {
    int pointNum = 0;
    if (bitMaps == null || bitMaps.get(columnIndex) == null) {
      pointNum = rowCount;
    } else {
      for (int i = 0; i < rowCount; i++) {
        int arrayIndex = i / ARRAY_SIZE;
        if (bitMaps.get(columnIndex).get(arrayIndex) == null) {
          pointNum++;
        } else {
          int elementIndex = i % ARRAY_SIZE;
          if (!bitMaps.get(columnIndex).get(arrayIndex).isMarked(elementIndex)) {
            pointNum++;
          }
        }
      }
    }
    return pointNum;
  }
@param rowIndex should be the sorted index.
iotdb-core/datanode/src/main/java/org/apache/iotdb/db/utils/datastructure/AlignedTVList.java