Re: Proposal: Recent mutated table tracking in memory

Hi Tatsuo,

Thank you for the thorough review and the fix to the tests!. Here's the
updated patch addressing all your comments.

re - replication_delay_source_cmd requirement

Good catch — the feature now also works when `delay_threshold_by_time > 0`.
I've added the TTL update call to `check_replication_time_lag()` (the
pg_stat_replication path), not just
`check_replication_time_lag_with_cmd()`. The docs are updated to reflect
that either `replication_delay_source_cmd` or `delay_threshold_by_time` can
provide the time-based delay.

re - Documentation compile error

Fixed — the xref was pointing to `runtime-config-track-table-mutation` but
the actual section ID is `runtime-config-table-mutation-map`.

Thanks again and looking forward to hearing back from you.

On Mon, Mar 23, 2026 at 6:13 AM Tatsuo Ishii <ishii(at)postgresql(dot)org> wrote:

>
> > Thank you for looking into this, fixing it and getting back to me.
> >
> > Looking forward to your update.
>
> It seems my commit fixed the issue.
>
> https://git.postgresql.org/gitweb/?p=pgpool2.git;a=commit;h=18f7f632de982d8fb5d0da2f2fdc48e26ac467e7
>
> So, I continue the review.
>
> + <para>
> + This feature requires <xref
> linkend="guc-replication-delay-source-cmd"> to be configured
> + for monitoring replication delay from replicas.
> + </para>
>
> Why this feature requires replication_delay_source_cmd to be set? Why
> can't we enable the feature as well when delay_threshold_by_time > 0?
> Both replication_delay_source_cmd and delay_threshold_by_time should
> provide standy delay in time, which provides enogh information to
> run the feature.
>
> 1. documentation
>
> - I get a compile error.
>
> openjade -wall -wno-unused-param -wno-empty -wfully-tagged -c
> /usr/share/sgml/docbook/stylesheet/dsssl/modular/catalog -d stylesheet.dsl
> -t sgml -i output-html -V html-index pgpool.sgml
> openjade:loadbalance.sgml:1122:21:X: reference to non-existent ID
> "RUNTIME-CONFIG-TRACK-TABLE-MUTATION"
>
> Best regards,
> --
> Tatsuo Ishii
> SRA OSS K.K.
> English: http://www.sraoss.co.jp/index_en/
> Japanese:http://www.sraoss.co.jp
>

--
Nadav Shatz
Tailor Brands | CTO