Re: We really ought to do something about O_DIRECT and data=journalled on ext4

Josh Berkus <josh@agliodbs.com> writes:
> It might be nice to add new sync_method options, "osync_odirect" and
> "odatasync_odirect" for DBAs who think they know enough to tune with
> non-defaults.

That would have the benefit that we'd not have to argue with people
who liked the current behavior (assuming there are any).  I'm not
sure there's much technical advantage, but from a political standpoint
it might be the easiest sort of change to push through.

However, this doesn't really address the question of what a sensible
choice of default is.  If there's little evidence about whether the
current flavor of open_datasync is really the fastest way, there's
none whatsoever that establishes open_datasync_without_o_direct
being a sane choice of default.

			regards, tom lane