Re: PG15 beta1 sort performance regression due to Generation context change

Hi,

On 2022-07-15 18:40:11 -0400, Jonathan S. Katz wrote:
> What I find interesting is the resistance to adding any documentation around
> this feature to guide users in case they hit the regression. I understand it
> can be difficult to provide guidance on issues related to adjusting
> work_mem, but even just a hint in the release notes to say "if you see a
> performance regression you may need to adjust work_mem" would be helpful.
> This would help people who are planning upgrades to at least know what to
> watch out for.

If we want to add that as boilerplate for every major release - ok, although
it's not really actionable.  What I'm against is adding it specifically for
this release - we have stuff like this *all the time*, we just often don't
bother to carefully find the specific point at which an optimization might
hurt.

Honestly, if this thread teaches anything, it's to hide relatively minor
corner case regressions. Which isn't good.

Greetings,

Andres Freund