Re: [HACKERS] Small improvement to compactify_tuples

Greetings,

* Юрий Соколов (funny(dot)falcon(at)gmail(dot)com) wrote:
> On Wed, Nov 29, 2017 at 8:00 AM, Peter Geoghegan <pg(at)bowt(dot)ie> wrote:
> > On Tue, Nov 28, 2017 at 2:41 PM, Andres Freund <andres(at)anarazel(dot)de> wrote:
> >> Maybe it's a stupid question. But would we still want to have this after
> >> the change? These should be just specializations of the template version
> >> imo.
>
> "generic" version operates on bytes, and it will be a bit hard to combine
> it with
> templated version. Not impossible, but it will look ugly.

If that's the case then does it really make sense to make this change..?

> In attach fixed qsort_template version.
> And version for compactify_tuples with bucket_sort and templated qsort.

While having the patch is handy, I'm not seeing any performance numbers
on this version, and I imagine others watching this thread are also
wondering about things like a test run that just uses the specialized
qsort_itemIds() without the bucketsort.

Are you planning to post some updated numbers and/or an updated test
case that hopefully shows best/worst case with this change? Would be
good to get that on a couple of platforms too, if possible, since we've
seen that the original benchmarks weren't able to be consistently
repeated across different platforms. Without someone doing that
leg-work, this doesn't seem like it'll be moving forward.

Marking as Waiting on Author.

Thanks!

Stephen