code: private Path getSplitPath(FileSplit inputSplit, JobConf conf) throws IOException {
      Path path = inputSplit.getPath();
      if (inputSplit instanceof OrcSplit) {
        OrcSplit orcSplit = (OrcSplit) inputSplit;
        List<Long> deltas = orcSplit.getDeltas();
        if (!orcSplit.hasBase() && deltas.size() >= 2) {
          throw new IOException("Cannot read valid StructTypeInfo from delta only file: " + path);
        }
      }
      LOG.debug("Input split path: {}", path);
      return path;
    }
docs: /*
  This is to work around an issue reading from ORC transactional data sets that contain only deltas. These contain
  synthesised column names that are not usable to us.