Hacker News Reader

They also have a system that's almost trivial to shard in any way they want, which would help even with postgres all around. Since there's no real interaction between users (only user-environment really), they can split databases by location, user groups, or some hashes as they want. Also the data they deal with is extremely cachable - as long as you play on one device.

View on HN

There is some, when users battle gyms they are battling with other users Pokemon which would be from anywhere in the world. When the Pokemon on the Gym loses it needs to be removed in a transaction with an update on the gym. This takes the easiest form of sharding off the table, so it's not as simple as you make it seem.

It doesn't really need to be a transaction since it is okay if it is eventually consistent (e.g. they have a cleanup job if a transaction is lost), that would be fine.

Reply on news.ycombinator.com