Yes, I read it and that is what I meant with "even if you tune all the settings and have statistics of remote tables". I have tried all the options, if you have

Yes, I read it and that is what I meant with "even if you tune all the settings and have statistics of remote tables". I have tried all the options, if you have any remote join which is more than a few rows you'll have a bad time. I'm not even talking about changing the shard key, even growing the cluster isn't easily done and much less with "millisecond latency". Unless you use Citus which technically isn't a pure PostgreSQL solution.