Thread

Re: Streamify more code paths

Xuneng Zhou <xunengzhou@gmail.com> — 2025-12-26T16:41:05Z

Hi Bilal,

Thanks for your review!

On Fri, Dec 26, 2025 at 6:59 PM Nazir Bilal Yavuz <byavuz81@gmail.com> wrote:
>
> Hi,
>
> Thank you for working on this!
>
> On Thu, 25 Dec 2025 at 09:34, Xuneng Zhou <xunengzhou@gmail.com> wrote:
> >
> > Hi,
> >
> > On Thu, Dec 25, 2025 at 1:51 PM Xuneng Zhou <xunengzhou@gmail.com> wrote:
> > >
> > > Hi Hackers,
> > >
> > > I noticed several additional paths in contrib modules, beyond [1],
> > > that are potentially suitable for streamification:
> > >
> > > 1) pgstattuple — pgstatapprox.c and parts of pgstattuple_approx_internal
> > > 2) Bloom — scan paths in blgetbitmap() and maintenance paths in blbulkdelete()
> > >
> > > The following patches streamify those code paths. No benchmarks have
> > > been run yet.
> > >
> > > [1] https://www.postgresql.org/message-id/flat/CABPTF7UeN2o-trr9r7K76rZExnO2M4SLfvTfbUY2CwQjCekgnQ%40mail.gmail.com
> > >
> > > Feedbacks welcome.
> > >
> >
> > One more in ginvacuumcleanup().
>
> 0001, 0002 and 0004 LGTM.
>
> 0003:
>
> +        buf = read_stream_next_buffer(stream, NULL);
> +        if (buf == InvalidBuffer)
> +            break;
>
> I think we are loosening the check here. We were sure that there were
> no InvalidBuffers until the nblocks. Streamified version does not have
> this check, it exits from the loop the first time it sees an
> InvalidBuffer, which may be wrong. You might want to add
> 'Assert(p.current_blocknum == nblocks);' before read_stream_end() to
> have a similar check.
>

Agree. The check has been added in v2 per your suggestion.

--
Best,
Xuneng