Re: Skipping schema changes in publication

On Thu, Jan 29, 2026 at 8:41 PM vignesh C <vignesh21@gmail.com> wrote:
>
> On Wed, 28 Jan 2026 at 10:46, shveta malik <shveta.malik@gmail.com> wrote:
> >
> > Thank You for the patch.
> >
> > 1)
> > There are certain parts of Approach 3 still present in Approach 1, as
> > an example:
> >
> > 1a)
> > +      For partitioned tables, only the root partitioned table may be specified
> > +      in <literal>EXCEPT TABLE</literal>.
> >
> > 1b)
> > + /*
> > + * Only the topmost ancestor of a partitioned table can be specified
> > + * in EXCEPT TABLES clause of a FOR ALL TABLES publication. So fetch
> > + * the publications excluding the topmost ancestor only.
> > + */
> > + GetRelationPublications(llast_oid(ancestors), NULL, &exceptpuboids);
> > +
> >
> > 1c)
> > + /* Check if the partiton is part of EXCEPT list of any publication */
> > + GetRelationPublications(RelationGetRelid(attachrel), NULL, &except_pubids);
> > + if (except_pubids != NIL)
> > + ereport(ERROR,
> > + (errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
> > + errmsg("cannot attach relation \"%s\" as partition because it is
> > part of EXCEPT list in publication",
> > + RelationGetRelationName(attachrel))));
> > +
> >
> > Overall, please take a diff of v35 and v37 to find such parts and
> > please correct these and others (if any).
> >
> > 2)
> > Also I don't think if below is correct statement for Approach 1:
> >
> > + * 2. For a partition, if the topmost ancestor is part of
> > + *   the EXCEPT TABLE list, we don't publish it.
> >
> > Even if any ancestor is part of EXECPT list (not only top most) we
> > should not publish that partition, isn't it?
> >
> > 3)
> > I tried a scenario and found that incremental replication is not
> > working correctly. Attached the failing test as Approach1_v37_fail.txt
> >
> > Once these basic things are corrected, I can review further.
>
> These comments are addressed in the v38 version patch attached.
> Currently the approach-3 changes is present separately in
> v38-0002-Restrict-EXCEPT-TABLE-to-root-partitioned-tables-apporach-3.patch
> which can be applied on top of
> v38-0001-Skip-publishing-the-tables-specified-in-EXCEPT-T.patch.
> Similarly the approach-1 changes is present separately in
> v38-0002-handle-EXCEPT-TABLE-correctly-with-partitioned-approach-1.patch
> which can be applied on top of
> v38-0001-Skip-publishing-the-tables-specified-in-EXCEPT-T.patch.
> Currently few of the query are logged as LOG messages, I will reduce
> the log level for these queries once few rounds of review are
> completed on the queries.
>

I was trying to test Approach 1 and haven’t fully reviewed or
validated it yet. A few initial observations:


postgres=# CREATE PUBLICATION pub1 for all tables
EXCEPT(tab_part_1,tab_part_2_p2) WITH
(PUBLISH_VIA_PARTITION_ROOT=true);
WARNING:  partition "tab_part_1" might be replicated as
publish_via_partition_root is "true"
WARNING:  partition "tab_part_2_p2" might be replicated as
publish_via_partition_root is "true"
CREATE PUBLICATION

postgres=# CREATE PUBLICATION pub1 for all tables
EXCEPT(tab_part_1,tab_part_2_p2) WITH
(PUBLISH_VIA_PARTITION_ROOT=false);
WARNING:  partitioned table "tab_part_1" might be replicated as
publish_via_partition_root is "false"
CREATE PUBLICATION

IIUC, these Warnings are not expected in Approach1.

thanks
Shveta