Bastiaan Olij <bastiaan@basenlily.me> writes:
> I just installed PG 9 on my Macbook (enterprisedb) just to start playing
> around with it. My Postgres 8.4 installation won't start now anymore, it
> is complaining about shared memory already being in use.
> Is it even possible to run PG 8 and PG 9 side by side? I was under the
> impression this was possible provided they listen on different ports?
Yes, it is, but the default SHMMAX on OS X is too small to allow
starting two postmasters at once. Crank up the shmem settings (see
our manual for details) and you should be fine.
regards, tom lane
