PoolConfig config = new PoolConfig();
			config.setAutoCommitOnClose(true);
			config.setInitialPoolSize(1);
			config.setMinPoolSize(1);
			config.setMaxPoolSize(Config.DATABASE_MAX_CONNECTIONS);
			config.setMaxStatements(100);
			config.setIdleConnectionTestPeriod(60); // test idle connection every 1 minute
			config.setMaxIdleTime(600); // remove unused connection after 10 minutes
			config.setNumHelperThreads(5);