Re: Expose last replayed timeline ID along with last replayed LSN

At Tue, 19 Jul 2022 14:28:40 +0530, Bharath Rupireddy <bharath(dot)rupireddyforpostgres(at)gmail(dot)com> wrote in
> Hi,
>
> At times it's useful to know the last replayed WAL record's timeline
> ID (especially on the standbys that are lagging in applying WAL while
> failing over - for reporting, logging and debugging purposes). AFICS,
> there's no function that exposes the last replayed TLI. We can either
> change the existing pg_last_wal_replay_lsn() to report TLI along with
> the LSN which might break the compatibility or introduce a new
> function pg_last_wal_replay_info() that emits both LSN and TLI. I'm
> fine with either of the approaches, but for now, I'm attaching a WIP
> patch that adds a new function pg_last_wal_replay_info().
>
> Thoughts?

There was a more comprehensive discussion [1], which went nowhere..

[1] https://www.postgresql.org/message-id/20191211052002.GK72921%40paquier.xyz

regadrs.

--
Kyotaro Horiguchi
NTT Open Source Software Center