pgsql.spam@vinz.nl writes:
> If one were certain his OS wouldn't do any re-ordering of writes, would it be
> safe to run with fsync = off? (not that I'm going to try this, but I'm just
> curious)
I suppose so ... but if your OS doesn't do *any* re-ordering of writes,
I'd say you need a better OS. Even in Postgres, we'd often like the OS
to collapse multiple writes of the same disk page into one write. And
we certainly want the various writes forced by a sync() to be done with
some intelligence about disk layout, not blindly in order of issuance.
regards, tom lane
