Re: Direct I/O

On Mon, Apr 17, 2023 at 12:06:23PM -0400, Tom Lane wrote:
> Robert Haas <robertmhaas(at)gmail(dot)com> writes:
> > On Sat, Apr 15, 2023 at 2:19 PM Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> >> I get the impression that we are going to need an actual runtime
> >> test if we want to defend against this. Not entirely convinced
> >> it's worth the trouble. Who, other than our deliberately rear-guard
> >> buildfarm animals, is going to be building modern PG with such old
> >> compilers? (And more especially to the point, on platforms new
> >> enough to have working O_DIRECT?)
>
> > I don't think that I fully understand everything under discussion
> > here, but I would just like to throw in a vote for trying to make
> > failures as comprehensible as we reasonably can.
>
> I'm not hugely concerned about this yet. I think the reason for
> slipping this into v16 as developer-only code is exactly that we need
> to get a feeling for where the portability dragons live.

Speaking of the developer-only status, I find the io_direct name more enticing
than force_parallel_mode, which PostgreSQL renamed due to overuse from people
expecting non-developer benefits. Should this have a name starting with
debug_?