Gregory Stark wrote:
> "Trevor Talbot" <quension@gmail.com> writes:
>
> > I gather postgres depends on it being at the same address, and fixing that
> > isn't trivial?
>
> I haven't been following the rest of the thread so I'm not sure if this is
> important. But no, fixing that should be relatively trivial as there are
> already some configurations where it's not the case (the EXEC_BACKEND case I
> believe). The rest of the system uses a shared memory base pointer and
> references everything relative to that.
This is inaccurate, I believe. The original Berkeley code did exec()
for backends and hence allowed shared memory to be at different
addresses for different backends, but we started using fork() and
eliminated much of that capability for performance and clarify reasons,
so right now all backends have to have shared memory at the same
address, and changing this will not be simple.
--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://www.enterprisedb.com
+ If your life is a hard drive, Christ can be your backup. +