Re: O_DIRECT for WAL writes

Neil Conway <neilc@samurai.com> writes:
> I wonder if we're benchmarking the right thing, though: is
> opening a file with O_DIRECT sufficient to ensure that a write(2) does
> not return until the data has hit disk?

Some googling suggests so, eg
http://www.die.net/doc/linux/man/man2/open.2.html

There are several useful tidbits about O_DIRECT on that page,
including this quote:

> "The thing that has always disturbed me about O_DIRECT is that the whole
> interface is just stupid, and was probably designed by a deranged monkey
> on some serious mind-controlling substances." -- Linus

Somehow I find that less than confidence-building...

            regards, tom lane