> "does the remote harden the transaction on the disk"
>
> Yes, but it is surely written to the LOG FILES, there's no warranty that it
> has already been written to the DATA FILES, although that's not a problem,
> since LOG FILES are designed to be played forward in the case of a server
> crash, replaying the commited transactions to the data files.
By hardening I meant only the WAL logs and not the data files.