In a classic single node configuration, a confirmation that its transaction isolation behaviors exhibited the corresponding anomalies would be valuable.
So I think there’s value in this ask.
I think he did something similar for MySQL when evaluating the Galera cluster.
In a single write master configuration, Postgres runs transactions concurrently, so the consistency analysis is still quite relevant.
I don’t think it’s a stretch to say that everyone expects Postgres to get top marks in this configuration and it would be worth confirming that this is the case.
But it was long ago, and maybe needs to be redone?
Edit: after re-reading it he treats it as a distributed system because client and server is over network. And that is true, it can also be thought of as a distributed system because as you said transactions are concurrent and are running as separate processes. Although in these cases you can't have a partition (which aphyr uses to find weaknesses), or maybe there is something equivalent that happens?
Not in itself, but it does offer a PREPARE TRANSACTION - COMMIT PREPARED / ROLLBACK PREPARED extension that could be used to add such support in the future. This would not be unprecedented, as the simpler case of db sharding is already being supported via the PARTITION BY feature, combined with "FOREIGN" database access.