@Override
  public void start() {
    super.start();
    if (keyedTable == null) {
      keyedTable = loadMixedTable(loader).asKeyedTable();
    }
    if (shouldEnumerate) {
      keyedTable.baseTable().refresh();
      keyedTable.changeTable().refresh();
      Collection<MixedFormatSplit> splits =
          splitPlanner.planSplits(null, scanContext.filters()).splits();
      assigner.onDiscoveredSplits(splits);
      LOG.info(
          "Discovered {} splits from table {} during job initialization",
          splits.size(),
          keyedTable.name());
    }
  }
This is a static mixed-format source enumerator, used for bounded source scan. Working enabled
only just {@link ScanContext#STREAMING} is equal to false.
amoro-format-mixed/amoro-mixed-flink/amoro-mixed-flink-common/src/main/java/org/apache/amoro/flink/read/hybrid/enumerator/StaticMixedFormatSourceEnumerator.java