Re: confirmed_flush_lsn shows LSN of the data that has not yet been received by the logical subscriber.

On Mon, Sep 19, 2022 at 5:24 PM Ashutosh Bapat
<ashutosh(dot)bapat(dot)oss(at)gmail(dot)com> wrote:
>
> On Mon, Sep 19, 2022 at 1:43 PM Ashutosh Sharma <ashu(dot)coek88(at)gmail(dot)com> wrote:
> >
> > On Fri, Sep 9, 2022 at 5:36 PM Ashutosh Bapat
> > <ashutosh(dot)bapat(dot)oss(at)gmail(dot)com> wrote:
> > >
> > > On Thu, Sep 8, 2022 at 8:32 PM Ashutosh Sharma <ashu(dot)coek88(at)gmail(dot)com> wrote:
> > > >
> > > > On Thu, Sep 8, 2022 at 6:23 PM Ashutosh Bapat
> > > > <ashutosh(dot)bapat(dot)oss(at)gmail(dot)com> wrote:
> > > > >
> > > > > On Thu, Sep 8, 2022 at 4:14 PM Ashutosh Sharma <ashu(dot)coek88(at)gmail(dot)com> wrote:
> > > Can you please point to the documentation.
> > >
> >
> > AFAIU there is just one documentation. Here is the link for it:
> >
> > https://www.postgresql.org/docs/current/view-pg-replication-slots.html
>
> Thanks. Description of confirmed_flush_lsn is "The address (LSN) up to
> which the logical slot's consumer has confirmed receiving data. Data
> older than this is not available anymore. NULL for physical slots."
> The second sentence is misleading. AFAIU, it really should be "Data
> corresponding to the transactions committed before this LSN is not
> available anymore". WAL before restart_lsn is likely to be removed but
> WAL with LSN higher than restart_lsn is preserved. This correction
> makes more sense because of the third sentence.
>

Thanks for the clarification. Attached is the patch with the changes.
Please have a look.

--
With Regards,
Ashutosh Sharma.