docs: def database_forwards(self, app_label, schema_editor, from_state, to_state):
          """Perform forward migration."""
          from resolwe.flow.models.data import DataQuerySet
          # pylint: disable=protected-access
  
          Data = from_state.apps.get_model('flow', 'Data')  # pylint: disable=invalid-name
          DataQuerySet._delete_chunked(Data.objects.filter(process__persistence='TMP'))
          DataQuerySet._delete_chunked(Data.objects.filter(status='ER'))