Re: Processes and caches in postgresql

On Mon, May 2, 2016 at 7:36 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
> On Wed, Apr 27, 2016 at 7:07 AM, Anastasia Lubennikova
> <a(dot)lubennikova(at)postgrespro(dot)ru> wrote:
>> Hi, hackers.
>> There's a couple of questions about processes.
>>
>> I found EXEC_BACKEND flag, while reading the code.
>> As I understood, it exists because we have to emulate fork() on WIN32.
>> And also it allows to debug the same behavior on Linux.
>> Is it right? Are there any other use cases?
>
> Right. Or, more precisely, we can't really emulate fork(), so we have
> to make due with what's available on Windows, which is basically
> exec().

There is library out there, unfortunately GPL licensed, that attempts
to fully implement posix including fork(): http://midipix.org/. One
of these days I'd like to have a go at porting postgres to it. Maybe
one day we can get rid of all that exec backend stuff :-).

merlin