When I've worked it in previous years the police presence inside was limited to the stalls thay they set up for public information and enjoyment, a couple of senior officers having cups of tea with the great and the good one serial of 6 officers to wander about.

It's outside that the police have "riot gear to hand" as the security is tight enough to prevent any trouble inside the event itself.

That said, i am unaware of any significant disorder this year though (outside or inside the event) which is very good news.