private NodeFileScanTask nodeFileScanTask(List<PrimaryKeyedFile> dataFiles) {
    List<DeleteFile> posDeleteList = input.positionDeleteForMixed();

    List<PrimaryKeyedFile> equlityDeleteList = input.equalityDeleteForMixed();

    List<PrimaryKeyedFile> allTaskFiles = new ArrayList<>();
    allTaskFiles.addAll(equlityDeleteList);
    allTaskFiles.addAll(dataFiles);

    List<MixedFileScanTask> fileScanTasks =
        allTaskFiles.stream()
            .map(file -> new BasicMixedFileScanTask(file, posDeleteList, table.spec()))
            .collect(Collectors.toList());
    return new NodeFileScanTask(fileScanTasks);
  }
This class is a temporary implementation, as readData and readDeleteData need to read the delete
file twice. Later on, it will be changed to read the delete file only once. Can read both
Mixed-hive and Mixed-iceberg format.
amoro-format-mixed/amoro-mixed-hive/src/main/java/org/apache/amoro/hive/optimizing/MixedHiveOptimizingDataReader.java