private static SessionFactory buildSessionFactory() {
		try {
			Configuration config = new Configuration().	addResource("/com/growup/time/manager/persistence/database.cfg.xml");
			ServiceRegistryBuilder registryBuilder = new ServiceRegistryBuilder();
			registryBuilder.applySettings(config.getProperties());
			registryBuilder.configure("/com/growup/time/manager/persistence/hibernate.cfg.xml");
			return config.buildSessionFactory(registryBuilder.buildServiceRegistry());			
		} catch (Throwable e) {
			logger.error("Loading hibernate configuration error", e);
			throw new ExceptionInInitializerError();
		}
	}