It’s not a quick nor easy thing to do a database dump, we use a cassandra cluster to store all the game state across several servers.
The JSON api is a lot less intensive and provides you with the game data without the comments and all of that, simply hit https://online-go.com/termination-api/game/<id> and you’ll see the json. That endpoint you can hit faster, I’m not quite sure what the practical limit is though. I’d say start at 20/s and see how that goes - please reach out to me as you’re doing it and I can monitor the system and let you know if you can go higher or if you need to scale back.