Re: [COMMITTERS] pgsql: Fix freezing of a dead HOT-updated tuple

Michael Paquier wrote:
> On Fri, Oct 6, 2017 at 10:18 PM, Alvaro Herrera <alvherre(at)alvh(dot)no-ip(dot)org> wrote:
> > Wood, Dan wrote:
> >> Yes, I’ve been testing 9.6. I’ll try Alvaro’s patch today.
> >>
> >> I would prefer to focus on either latest 9X or 11dev.
> >
> > I tested my patch on 9.4 and 9.5 today and it seems to close the problem
> > (with the patch, I waited 10x as many iterations as it took for the
> > problem to occur ~10 times without the patch), but I can reproduce a
> > problem in 9.6 with my patch installed. There must be something new in
> > 9.6 that is causing the problem to reappear.
>
> The freeze visibility map has been introduced in 9.6... There could be
> interactions on this side.

Ah, thanks for the tip. I hope the authors of that can do the gruntwork
of researching this problem there, then. I'll go commit what I have
now.

--
Álvaro Herrera https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services