Re: WIP: Upper planner pathification

Hi,

On 2016-02-28 15:03:28 -0500, Tom Lane wrote:
> Those with long memories will recall that I've been waving my arms about
> $SUBJECT for more than five years. I started to work seriously on a patch
> last summer, and here is a version that I feel comfortable exposing to
> public scrutiny (which is not to call it "done"; more below).

Yay!

> So, where to go from here? I'm acutely aware that we're hard up against
> the final 9.6 commitfest, and that we discourage major patches arriving
> so late in a devel cycle. But I simply couldn't get this done any faster.
> I don't really want to hold it over for the 9.7 devel cycle. It's been
> enough trouble maintaining this patch in the face of conflicting commits
> over the last year or so (it's probably still got bugs related to parallel
> query...), and there definitely are conflicting patches in the upcoming
> 'fest. And the lack of this infrastructure is blocking progress on FDWs
> and some other things.
>
> So I'd really like to get this into 9.6. I'm happy to put it into the
> March commitfest if someone will volunteer to review it.

Hard. This is likely to cause/trigger a number of bugs, and we don't
have much time to let this mature. It's a change that we're unlikely to
be able to back-out if we discover that it wasn't the right thing to
integrate shortly before the release. On the other hand, this is a
major architectural step forward; one that unblocks a number of nice
features. There's also an argument to be made that integrating this now
is beneficial, because it'll cause less churn for patches being
developed while 9.6 is stabilizing.

Greetings,

Andres Freund