Re: Shared memory changes in 9.4?

Hi,

On 2014-06-12 11:08:35 -0400, Robert Haas wrote:
> On Thu, Jun 12, 2014 at 5:41 AM, Andres Freund <andres(at)2ndquadrant(dot)com> wrote:
> >> > With regard to Andres' proposal, I'm not that keen on setting
> >> > dynamic_shared_memory_type='none' by default.
> >
> > Note that I'm not proposing to disable the whole thing. Just that a
> > unset dynamic_shared_memory_type doesn't configure dsm. Initdb would
> > still configure it after probing.
>
> OK, I misunderstood your position; thanks for clarifying. I think
> that would be OK with me. To some degree, I think that the test setup
> is broken by design: while we try to maintain backward-compatibility
> for postgresql.conf files, there's never been any guarantee that an
> old postgresql.conf file will work on a newer server. For example, a
> whole lot of pre-8.4 users probably had max_fsm_pages and
> max_fsm_relations configured, and with 8.4, those settings went away.
> Fixing that kind of thing is an essential part of the upgrade process.

While I think I see where you're coming from I don't think these cases
are comparable. In this case commenting out the GUC can prevent the
server from starting. That's pretty odd imo.

Greetings,

Andres Freund

--
Andres Freund http://www.2ndQuadrant.com/
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