Re: Posix Shared Mem patch

Magnus Hagander <magnus(at)hagander(dot)net> writes:
> On Thu, Jun 28, 2012 at 7:00 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>> A related question is - if we do this - should we enable it only on
>> ports where we've verified that it works, or should we just turn it on
>> everywhere and fix breakage if/when it's reported? I lean toward the
>> latter.

> Depends on the amount of expected breakage, but I'd lean towards teh
> later as well.

If we don't turn it on, we won't find out whether it works. I'd say try
it first and then back off if that proves necessary. I'd just as soon
not see us write any fallback logic without evidence that it's needed.

FWIW, even my pet dinosaur HP-UX 10.20 box appears to support
mmap(MAP_SHARED|MAP_ANONYMOUS) --- at least the mmap man page documents
both flags. I find it really pretty hard to believe that there are any
machines out there that haven't got this and yet might be expected to
run PG 9.3+. We should not go into it with an expectation of failure,
anyway.

regards, tom lane