Really nice, Thanks a lot for the info and review. Taken into the patch. Regards, Renzo Dani
On Thu, Oct 16, 2025 at 5:32 AM Fujii Masao <[email protected]> wrote: > On Thu, Oct 16, 2025 at 12:47 AM Renzo Dani <[email protected]> wrote: > > > > Hi, > > recently I had some issue understanding what was going on with a replica > and the reported xmin. > > I have than created a patch to better specify the value expected into > the pg_stat_replication.backend_xmin field. > > +1 > > + This field will be null if a replication slot is used; in that > case, the xmin is available through <link > linkend="view-pg-replication-slots">pg_replication_slots</link>. > > I think it would be better to also mention that this field is null > when hot_standby_feedback is disabled. > > Also, <literal> tags should be used for "xmin", and a newline should > be added to avoid an overly long line. > > Based on the above comments, how about revising it as follows? > > + This field will be null if a replication slot is used (in this > case, > + the standby's <literal>xmin</literal> is shown in > + <link > linkend="view-pg-replication-slots">pg_replication_slots</link>) > + or if <varname>hot_standby_feedback</varname> is disabled. > > Regards, > > -- > Fujii Masao >
From 6ec4b38af5e1f5d90e8de7ef2ac073761a362b5d Mon Sep 17 00:00:00 2001 From: Renzo Dani <[email protected]> Date: Wed, 15 Oct 2025 17:31:45 +0200 Subject: [PATCH v2 1/2] Extend documentation for pg_stat_replication.backend_xmin --- doc/src/sgml/monitoring.sgml | 1 + 1 file changed, 1 insertion(+) diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index dc4fc29466d..c616571e4df 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -1287,6 +1287,7 @@ description | Waiting for a newly initialized WAL file to reach durable storage <para> This standby's <literal>xmin</literal> horizon reported by <xref linkend="guc-hot-standby-feedback"/>. + This field will be null if a replication slot is used; in that case, the xmin is available through <link linkend="view-pg-replication-slots">pg_replication_slots</link>. </para></entry> </row> -- 2.43.0
From dcbf173c712437edba68a675a63d96ed5ac2f2c9 Mon Sep 17 00:00:00 2001 From: Renzo Dani <[email protected]> Date: Thu, 16 Oct 2025 08:06:17 +0200 Subject: [PATCH v2 2/2] Extend documentation for pg_stat_replication.backend_xmin Additional information for hot_standby_feedback --- doc/src/sgml/monitoring.sgml | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/doc/src/sgml/monitoring.sgml b/doc/src/sgml/monitoring.sgml index c616571e4df..d5f0fb7ba7c 100644 --- a/doc/src/sgml/monitoring.sgml +++ b/doc/src/sgml/monitoring.sgml @@ -1287,7 +1287,10 @@ description | Waiting for a newly initialized WAL file to reach durable storage <para> This standby's <literal>xmin</literal> horizon reported by <xref linkend="guc-hot-standby-feedback"/>. - This field will be null if a replication slot is used; in that case, the xmin is available through <link linkend="view-pg-replication-slots">pg_replication_slots</link>. + This field will be null if a replication slot is used (in this case, + the standby's <literal>xmin</literal> is shown in + <link linkend="view-pg-replication-slots">pg_replication_slots</link>) + or if <varname>hot_standby_feedback</varname> is disabled. </para></entry> </row> -- 2.43.0
