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From: Shinya Kato <shinya11.kato@gmail.com>
Date: Sat, 21 Mar 2026 11:04:32 +0900
Message-ID: 
 <CAOzEurSAvOf-vxzn9yQaCipgD6bSr4ncoTYjFceAPDO5fzMNNw@mail.gmail.com>
Subject: Re: pg_stat_replication.*_lag sometimes shows NULL during active
 replication
To: Fujii Masao <masao.fujii@gmail.com>
Cc: PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
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On Fri, Mar 20, 2026 at 2:13=E2=80=AFAM Fujii Masao <masao.fujii@gmail.com>=
 wrote:
> I think the issue occurs when the positions in the first message point to
> the same LSN (e.g., 0/030D5230), and the second message reports the same =
but
> larger LSN (e.g., 0/030D52E0).

Thanks for the explanation!

> I've updated the patch to address this. It removes fullyAppliedLastTime,
> tracks the positions from the previous reply, and clears the lag values o=
nly
> when the positions remain unchanged across two consecutive messages.
>
> Patch attached. Could you test and review this updated patch?

The patch works properly. I think it looks nice to me, except for the
typo I sent in the previous message.


--=20
Best regards,
Shinya Kato
NTT OSS Center