Re: Improve heapgetpage() performance, overhead from serializable - Mailing list pgsql-hackers

Hi,

On 2023-09-05 14:42:57 +0700, John Naylor wrote:
> On Mon, Jul 17, 2023 at 9:58 PM Andres Freund <andres@anarazel.de> wrote:
>
> > FWIW, there's more we can do, with some hacky changes I got the time down
> to
> > 273.261, but the tradeoffs start to be a bit more complicated. And
> 397->320ms
> > for something as core as this, is imo worth considering on its own.
>
> Nice!
>
> > On 2023-07-17 09:55:07 +0800, Zhang Mingli wrote:
>
> > > Does it make sense to combine if else condition and put it to the
> incline function’s param?
> > >
> > > Like:
> > > scan->rs_ntuples = heapgetpage_collect(scan, snapshot, page, buffer,
> > >
>                          block, lines, all_visible, check_serializable);
> >
> > I think that makes it less likely that the compiler actually generates a
> > constant-folded version for each of the branches. Perhaps worth some
> > experimentation.
>
> Combining this way doesn't do so for me.

Are you saying that the desired constant folding happened after combining the
branches, or that it didn't happen?

Greetings,

Andres Freund