>> These raw tps suggest that {backend,bgwriter}_flush_after should better be
>> zero for this kind of load.Whether it should be the default is unclear yet,
>> because as Andres pointed out this is one kind of load.
>
> FWIW, I don't think {backend,bgwriter} are the same here. It's primarily
> backend that matters.
Indeed, I was a little hasty to put bgwriter together based on this
report.
I'm a little wary of "bgwriter_flush_after" though, I would not be
surprised if someone reports some regressions, although probably not with
a pgbench tpcb kind of load.
--
Fabien.