Re: [PATCH] kNN for btree

On Mon, Jul 1, 2019 at 8:47 PM Nikita Glukhov <n(dot)gluhov(at)postgrespro(dot)ru> wrote:
> On 01.07.2019 13:41, Thomas Munro wrote:
> > On Tue, Mar 26, 2019 at 4:30 AM Nikita Glukhov <n(dot)gluhov(at)postgrespro(dot)ru> wrote:
> >>>> Fixed two bugs in patches 3 and 10 (see below).
> >>>> Patch 3 was extracted from the main patch 5 (patch 4 in v9).
> >>> This patch no longer applies so marking Waiting on Author.
> >> Attached 11th version of the patches rebased onto current master.
> > Hi Nikita,
> >
> > Since a new Commitfest is here and this doesn't apply, could we please
> > have a fresh rebase?
>
> Attached 12th version of the patches rebased onto the current master.

I have more thoughts about planner/executor infrastructure. It
appears that supporting "ORDER BY col1, col2 <-> val" is too complex
for initial version of patch. Handling of "ORDER BY col" and "ORDER
BY col <-> val" cases uses different code paths in optimizer.

So, I'd like to limit first version of this patch to support just most
simple "ORDER BY col <-> val" case. We would probably be able to
enhance it even in v13 release cycle, but let's start with just simple
case. I also think we can evade replacing amcanorderbyop flag with
method, but introduce just new boolean flag indicating knn supports
only first column.

------
Alexander Korotkov

Postgres Professional: http://www.postgrespro.com
The Russian Postgres Company