Node.js PostgreSQL notification server

notification_server.js

const SOCKETIO_LISTEN_PORT = 81;
const PG_CONNECTION_STRING = 'postgres://dor@localhost/app';
const PG_NOTIFICATION_CHANNEL = 'notifications';

var pg = require('pg'),
	sio = require('socket.io').listen(SOCKETIO_LISTEN_PORT);

var db = new pg.Client(PG_CONNECTION_STRING);
db.connect();

sio.sockets.on('connection', function(socket)
{
	socket.on('join', socket.join);
});

db.on('notification', function(data)
{
	var model = JSON.parse(data.payload);
	var room = 'event_'+ model.event_pk;

	console.log('emitting notification #%d to room "%s"', model.pk, room);

	sio.sockets.in(room).emit('notification', model);
});

db.query('LISTEN ' + PG_NOTIFICATION_CHANNEL);