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

Marti Raudsepp <marti(at)juffo(dot)org> writes:
> On Tue, Dec 7, 2010 at 03:34, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>> To my mind, O_DIRECT is not really the key issue here, it's whether to
>> prefer O_DSYNC or fdatasync.

> Since different platforms implement these primitives differently, and
> it's not always clear from the header file definitions which options
> are actually implemented, how about simply hard-coding a default value
> for each platform?

There's not a fixed finite list of "platforms we support". In general
we prefer to avoid designing things that way at all. If we have to have
specific exceptions for specific platforms, we grin and bear it, but for
the most part behavioral differences ought to be driven by configure's
probes for platform features.

regards, tom lane