I'm wondering what that performance actually looks like though. The closest benchmark I have is a single postgres instance with a uuid pkey and a bigint column,

I'm wondering what that performance actually looks like though. The closest benchmark I have is a single postgres instance with a uuid pkey and a bigint column, transactionally incrementing the integer in the column. I mean I guess mathing it out, updating an atomic integer is ~2-100ns, depending on contention. If you need to coordinate the writes you have anywhere from ~250μs-10ms. We can basically throw away the increment at that point since the network is hundreds/thousands of times slower. So at 10ms, that's 100 op/s. At 250μs more like 40kops/s. That ignores the fact that your db can perform those writes concurrently and then batch the writes off to the other database, so long as it doesn't pretend that they're all committed at once. psql HOT updates would presumably be a thing here idk. If I had to guess, I'd lean towards the "40kop/s" being closer than the "100op/s" but idk! I wish we had benchmarks but I can't find anything :\