Re: Proposal: Conflict log history table for Logical Replication

On Tue, 21 Apr 2026 at 15:21, Dilip Kumar <dilipbalaut(at)gmail(dot)com> wrote:
>
> On Mon, Apr 20, 2026 at 7:31 PM Nisha Moond <nisha(dot)moond412(at)gmail(dot)com> wrote:
> >
> > On Mon, Apr 20, 2026 at 5:25 PM Nisha Moond <nisha(dot)moond412(at)gmail(dot)com> wrote:
> > >
> > > On Thu, Apr 16, 2026 at 9:24 PM Dilip Kumar <dilipbalaut(at)gmail(dot)com> wrote:
> > > >
> > > > On Fri, Apr 10, 2026 at 4:54 PM Nisha Moond <nisha(dot)moond412(at)gmail(dot)com> wrote:
> > > > >
> > > > > Hi Dilip,
> > > > > I’m planning to review/test the feature patches, but they don’t apply
> > > > > cleanly on the latest HEAD. Could you please rebase them?
> > > > >
> > > > Thanks Nisha. Here is the rebased version
> > >
> > > Thank you Dilip. I reviewed the patches and did basic testing.
> > >
> > > Here are a few comments for the first two patches -
> >
> > Please find further comments for the document patch-0003:
> >
> > 1) File: /doc/src/sgml/logical-replication.sgml
> > + <xref linkend="logical-replication-conflict-log-schema"/>.
> > + </para>
> > +
> > + <table id="logical-replication-conflict-log-schema">
> > + <title>Conflict Log Table Schema</title>
> >
> > The "replica_identity" column is missing from the schema table in docs.
> > ~~~
> >
> > Few minor comments:
> > 2) File: /doc/src/sgml/logical-replication.sgml: couple of typos in
> > below change-
> > - The log format for logical replication conflicts is as follows:
> > + The <link linkend="sql-createsubscription-params-with-conflict-log-destination"><literal>conflict_log_destination</literal></link>
> > + parameter can automatically creates a dedicated conflict log
> > table. This table is created in the dedicated
> > + <literal>pg_conflict</literal> namespace. The name of the
> > conflict log table
> > + is <literal>pg_conflict_&lt;subid&gt;</literal>. The predefined
> > schema of this table is
> > + detailed in
> > + <xref linkend="logical-replication-conflict-log-schema"/>.
> > + </para>
> >
> > 2a) "can automatically creates" / "automatically creates"
> > 2b) there are double spaces after full stop.
> > "conflict log table. This table "
> > " namespace. The name of the conflict"
> > ~~~
> >
> > 3) Commit message typo -
> > Doccumentation patch / Documentation patch
> > ~~~
> >
> > 4) File: /doc/src/sgml/ref/alter_subscription.sgml
> > + When the <link
> > linkend="sql-createsubscription-params-with-conflict-log-destination"><literal>conflict_log_destination</literal></link>
> > + parameter is set to <literal>table</literal> or
> > <literal>all</literal>, the system
> > + automatically creates the internal conflict log table if it
> > does not already
> > + exist.
> >
> > The phrase “if it does not already exist” seems misleading here. The
> > table shouldn’t pre-exist, as it’s always dropped and recreated when
> > conflict_log_destination changes. Let me know if I’m missing any case
> > where it could pre-exist.
> > ~~~
>
> Thanks Nisha for the review. All your comments make sense so I have
> fixed them in the latest patch.

When the owner of a subscription is changed, the ownership of the
subscription itself is updated, but the ownership of the associated
conflict log table remains unchanged.
-- Change the owner of the subscription
postgres=# ALTER SUBSCRIPTION sub3 OWNER TO test;
ALTER SUBSCRIPTION

-- Verify subscription owner
postgres=# SELECT subname, subowner FROM pg_subscription WHERE subname = 'sub3';
subname | subowner
---------+----------
sub3 | 16426
(1 row)

-- Verify conflict log table owner
postgres=# SELECT relname, relowner FROM pg_class WHERE relname =
'pg_conflict_16431';
relname | relowner
-------------------+----------
pg_conflict_16431 | 10
(1 row)

The subscription owner is updated as expected, but the conflict log
table continues to be owned by the original owner.
Is this behavior intentional?

Regards,
Vignesh