Re: Direct I/O

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. When (and
if) we try to make O_DIRECT mainstream, yes we'd better be sure that
any known failure cases are reported well. But we need the data
about which those are, first.

regards, tom lane