Re: parallel mode and parallel contexts

On Fri, Feb 13, 2015 at 2:22 AM, Michael Paquier
<michael(dot)paquier(at)gmail(dot)com> wrote:
> On Thu, Feb 12, 2015 at 3:59 AM, Robert Haas <robertmhaas(at)gmail(dot)com> wrote:
>>
>> We're not seeing eye to eye here yet, since I don't accept your
>> example scenario and you don't accept mine. Let's keep discussing.
>>
>> Meanwhile, here's an updated patch.
>
> A lot of cool activity is showing up here, so moved the patch to CF 2015-02.
> Perhaps Andres you could add yourself as a reviewer?

Here's a new version of the patch with (a) some additional
restrictions on heavyweight locking both at the start of, and during,
parallel mode and (b) a write-up in the README explaining the
restrictions and my theory of why the handling of heavyweight locking
is safe. Hopefully this goes some way towards addressing Andres's
concerns. I've also replaced the specific (and wrong) messages about
advisory locks with a more generic message, as previously proposed;
and I've fixed at least one bug.

--
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company