Re: [BackendXidGetPid] only access allProcs when xid matches

On Thu, Sep 7, 2023 at 5:07 PM Ashutosh Bapat
<ashutosh.bapat.oss@gmail.com> wrote:
>
> Forgot to attach the patch.

LGTM

Should I change the status to ready for committer now?

>
> On Thu, Sep 7, 2023 at 1:22 PM Ashutosh Bapat
> <ashutosh.bapat.oss@gmail.com> wrote:
> >
> > Hi Junwang,
> > We leave a line blank after variable declaration as in the attached patch.
> >
> > Otherwise the patch looks good to me.
> >
> > The function modified by the patch is only used by extension
> > pgrowlocks. Given that the function will be invoked as many times as
> > the number of locked rows in the relation, the patch may show some
> > improvement and thus be more compelling. One way to measure
> > performance is to create a table with millions of rows, SELECT all
> > rows with FOR SHARE/UPDATE clause. Then run pgrowlock() on that
> > relation. This will invoke the given function a million times. That
> > way we might be able to catch some miniscule improvement per row.
> >
> > If the performance is measurable, we can mark the CF entry as ready
> > for committer.
> >
> > --
> > Best Wishes,
> > Ashutosh Bapat
> >
> > On Thu, Aug 10, 2023 at 1:48 PM Junwang Zhao <zhjwpku@gmail.com> wrote:
> > >
> > > On Thu, Aug 10, 2023 at 4:11 PM Ashutosh Bapat
> > > <ashutosh.bapat.oss@gmail.com> wrote:
> > > >
> > > > Please add this to commitfest so that it's not forgotten.
> > > >
> > >
> > > Added [1], thanks
> > >
> > > [1]: https://commitfest.postgresql.org/44/4495/
> > >
> > > > On Wed, Aug 9, 2023 at 8:37 PM Junwang Zhao <zhjwpku@gmail.com> wrote:
> > > > >
> > > > > On Wed, Aug 9, 2023 at 10:46 PM Ashutosh Bapat
> > > > > <ashutosh.bapat.oss@gmail.com> wrote:
> > > > > >
> > > > > > On Wed, Aug 9, 2023 at 9:30 AM Junwang Zhao <zhjwpku@gmail.com> wrote:
> > > > > > >
> > > > > > > In function `BackendXidGetPid`, when looping every proc's
> > > > > > >     TransactionId, there is no need to access its PGPROC since there
> > > > > > >     is shared memory access: `arrayP->pgprocnos[index]`.
> > > > > > >
> > > > > > >     Though the compiler can optimize this kind of inefficiency, I
> > > > > > >     believe we should ship with better code.
> > > > > > >
> > > > > >
> > > > > > Looks good to me. However, I would just move the variable declaration
> > > > > > with their assignments inside the if () rather than combing the
> > > > > > expressions. It more readable that way.
> > > > >
> > > > > yeah, make sense, also checked elsewhere using the original style,
> > > > > attachment file
> > > > > keep that style, thanks ;)
> > > > >
> > > > > >
> > > > > > --
> > > > > > Best Wishes,
> > > > > > Ashutosh Bapat
> > > > >
> > > > >
> > > > >
> > > > > --
> > > > > Regards
> > > > > Junwang Zhao
> > > >
> > > >
> > > >
> > > > --
> > > > Best Wishes,
> > > > Ashutosh Bapat
> > >
> > >
> > >
> > > --
> > > Regards
> > > Junwang Zhao
>
>
>
> --
> Best Wishes,
> Ashutosh Bapat



--
Regards
Junwang Zhao