@Override
  public String writeToString() {
    StringBuilder buf = new StringBuilder();
    if (tableName == null) {
      buf.append("null");
    } else {
      buf.append(tableName);
    }
    buf.append(':');
    buf.append(highWatermark);
    buf.append(':');
    buf.append(minOpenWriteId);
    if (exceptions.length == 0) {
      buf.append(':');  // separator for open write ids
      buf.append(':');  // separator for aborted write ids
    } else {
      StringBuilder open = new StringBuilder();
      StringBuilder abort = new StringBuilder();
      for (int i = 0; i < exceptions.length; i++) {
        if (abortedBits.get(i)) {
          if (abort.length() > 0) {
            abort.append(',');
          }
          abort.append(exceptions[i]);
        } else {
          if (open.length() > 0) {
            open.append(',');
          }
          open.append(exceptions[i]);
        }
      }
      buf.append(':');
      buf.append(open);
      buf.append(':');
      buf.append(abort);
    }
    return buf.toString();
  }
We cannot use a base file if its range contains an open write id.
@param writeId from base_xxxx
storage-api/src/java/org/apache/hadoop/hive/common/ValidReaderWriteIdList.java