Re: Feature: POSIX Shared memory support

>> Then, how about semaphores?  When I just do configure, PostgreSQL
>> seems to use SysV semaphores.  But POSIX semaphore implementation
is
>> prepared in src/backend/port/posix_sema.c.  Why isn't it used by
>> default?  Does it have any problem?
>>
>
> Either way, Essentially, no one is running out of shared memory due
> to semaphores.
> In this case, semaphore usage is unrelated to shared memory
> shortages.

Yes, of course, shared memory is not related to semaphores.

> Also, on many platforms the posix_sema's code is used.

Really?  When I run 'configure' without any parameter on Red Hat
Enterprise Linux 4.0 (kernel 2.6.x), PostgreSQL uses SysV semaphores.
I confirmed that by seeing the result of 'ipcs -u'.  What platforms is
POSIX sema used by PostgreSQL by default?