Thread

Re: Streamify more code paths

Xuneng Zhou <xunengzhou@gmail.com> — 2025-12-30T02:43:17Z

Hi,

On Tue, Dec 30, 2025 at 9:51 AM Xuneng Zhou <xunengzhou@gmail.com> wrote:
>
> Hi,
>
> Thanks for looking into this.
>
> On Mon, Dec 29, 2025 at 6:58 PM Nazir Bilal Yavuz <byavuz81@gmail.com> wrote:
> >
> > Hi,
> >
> > On Sun, 28 Dec 2025 at 14:46, Xuneng Zhou <xunengzhou@gmail.com> wrote:
> > >
> > > Hi,
> > > >
> > > > Two more to go:
> > > > patch 5: Streamify log_newpage_range() WAL logging path
> > > > patch 6: Streamify hash index VACUUM primary bucket page reads
> > > >
> > > > Benchmarks will be conducted soon.
> > > >
> > >
> > > v6 in the last message has a problem and has not been updated. Attach
> > > the right one again. Sorry for the noise.
> >
> > 0003 and 0006:
> >
> > You need to add 'StatApproxReadStreamPrivate' and
> > 'HashBulkDeleteStreamPrivate' to the typedefs.list.
>
> Done.
>
> > 0005:
> >
> > @@ -1321,8 +1341,10 @@ log_newpage_range(Relation rel, ForkNumber forknum,
> >          nbufs = 0;
> >          while (nbufs < XLR_MAX_BLOCK_ID && blkno < endblk)
> >          {
> > -            Buffer        buf = ReadBufferExtended(rel, forknum, blkno,
> > -                                                 RBM_NORMAL, NULL);
> > +            Buffer        buf = read_stream_next_buffer(stream, NULL);
> > +
> > +            if (!BufferIsValid(buf))
> > +                break;
> >
> > We are loosening a check here, there should not be a invalid buffer in
> > the stream until the endblk. I think you can remove this
> > BufferIsValid() check, then we can learn if something goes wrong.
>
> My concern before for not adding assert at the end of streaming is the
> potential early break in here:
>
> /* Nothing more to do if all remaining blocks were empty. */
> if (nbufs == 0)
>     break;
>
> After looking more closely, it turns out to be a misunderstanding of the logic.
>
> > 0006:
> >
> > You can use read_stream_reset() instead of read_stream_end(), then you
> > can use the same stream with different variables, I believe this is
> > the preferred way.
> >
> > Rest LGTM!
> >
>
> Yeah, reset seems a more proper way here.
>

Run pgindent using the updated typedefs.list.

-- 
Best,
Xuneng