private List<DataFile> loadDataFiles(TableIdentifier ident) throws AnalysisException {
    PartitionSpec spec =
        SparkSchemaUtil.specForTable(spark, ident.database().get() + "." + ident.table());

    if (spec.equals(PartitionSpec.unpartitioned())) {
      return listUnPartitionedSparkTable(spark, ident);
    } else {
      List<SparkTableUtil.SparkPartition> sparkPartitions =
          SparkTableUtil.getPartitions(spark, ident, Maps.newHashMap());
      Preconditions.checkArgument(
          !sparkPartitions.isEmpty(), "Cannot find any partitions in table %s", ident);
      return listPartitionDataFiles(spark, sparkPartitions, spec);
    }
  }
migrate a v1 table to mixed-format table. will reuse file in v1 table , but delete metadata in
session catalog
amoro-format-mixed/amoro-mixed-spark/v3.3/amoro-mixed-spark-3.3/src/main/java/org/apache/amoro/spark/command/MigrateToMixedFormatCommand.java