code: private void updateChunksInProjectVersions(final DatabaseTransOperator transOperator,
        final int projectId, final int version, final int chunk)
        throws ProjectManagerException {
  
      final String UPDATE_PROJECT_NUM_CHUNKS =
          "UPDATE project_versions SET num_chunks=? WHERE project_id=? AND version=?";
      try {
        transOperator.update(UPDATE_PROJECT_NUM_CHUNKS, chunk, projectId, version);
        transOperator.getConnection().commit();
      } catch (final SQLException e) {
        logger.error("Error updating project " + projectId + " : chunk_num " + chunk, e);
        throw new ProjectManagerException(
            "Error updating project " + projectId + " : chunk_num " + chunk, e);
      }
    }
docs: we update num_chunks's actual number to db here.