Re: [PATCH v1] Fix initial sync of zero-column published tables

[Peter Smith]

On Thu, Nov 5, 2026 at 1:48 PM Mingjie Gao <mingjie....@gmail.com> wrote:
...
> Please find the updated v2 patch attached.
>

Some minor comments for the v2 test code.

======
src/test/subscription/t/008_diff_schema.pl

1.
+ CREATE PUBLICATION pub_nocols FOR TABLE tab_nocols
+ WITH (publish = 'insert');

Saying publish = 'insert' seems overkill.

~~~

2.
+ $node_subscriber->safe_psql('postgres', 'DROP SUBSCRIPTION sub_nocols');
+ $node_publisher->safe_psql('postgres',
+ 'DROP PUBLICATION pub_nocols; DROP TABLE tab_nocols');
+ $node_subscriber->safe_psql('postgres', 'DROP TABLE tab_nocols');

Those could be combined a bit...

~~~

3. Other misc refactoring

some spaces
some comments
some more consistent use of terminating ';'
etc.

~~~

I've made a few tmp changes (only cosmetic -- nothing functional).
e.g., see my attached version of the 008_diff_schema.pl changes for reference.

======
Kind Regards,
Peter Smith.
Fujitsu Australia

diff --git a/src/test/subscription/t/008_diff_schema.pl 
b/src/test/subscription/t/008_diff_schema.pl
index 96e3d6f5888..fbdfcda3f51 100644
--- a/src/test/subscription/t/008_diff_schema.pl
+++ b/src/test/subscription/t/008_diff_schema.pl
@@ -31,6 +31,63 @@ $node_subscriber->safe_psql('postgres',
 
 # Setup logical replication
 my $publisher_connstr = $node_publisher->connstr . ' dbname=postgres';
+
+# A zero-column publisher still sends rows.  Subscriber-only columns must
+# get their defaults during initial COPY as well as incremental replication.
+foreach my $binary ('false', 'true')
+{
+       $node_publisher->safe_psql(
+               'postgres', q{
+               CREATE TABLE tab_nocols ();
+               INSERT INTO tab_nocols DEFAULT VALUES;
+               INSERT INTO tab_nocols DEFAULT VALUES;
+               CREATE PUBLICATION pub_nocols FOR TABLE tab_nocols;
+       });
+       $node_subscriber->safe_psql('postgres',
+               "CREATE TABLE tab_nocols (local_value text DEFAULT 
'subscriber-default')"
+       );
+       $node_subscriber->safe_psql('postgres',
+               "CREATE SUBSCRIPTION sub_nocols CONNECTION '$publisher_connstr' 
PUBLICATION pub_nocols WITH (binary = $binary)"
+       );
+
+       # test initial sync
+       $node_subscriber->wait_for_subscription_sync($node_publisher, 
'sub_nocols');
+
+       is( $node_subscriber->safe_psql(
+                       'postgres', q{
+                       SELECT count(*) FROM tab_nocols
+                       WHERE local_value = 'subscriber-default';
+               }),
+               '2',
+               "initial zero-column rows use local defaults (binary = 
$binary)");
+
+       # test incremental replication
+       $node_publisher->safe_psql('postgres', 
+               "INSERT INTO tab_nocols DEFAULT VALUES");
+
+       $node_publisher->wait_for_catchup('sub_nocols');
+
+       is( $node_subscriber->safe_psql(
+                       'postgres', q{
+                       SELECT count(*) FROM tab_nocols
+                       WHERE local_value = 'subscriber-default';
+               }),
+               '3',
+               "incremental zero-column rows use local defaults (binary = 
$binary)");
+
+       # cleanup
+       $node_subscriber->safe_psql(
+               'postgres', q{
+               DROP SUBSCRIPTION sub_nocols;
+               DROP TABLE tab_nocols;
+       });
+       $node_publisher->safe_psql(
+               'postgres', q{
+               DROP PUBLICATION pub_nocols;
+               DROP TABLE tab_nocols;
+       });
+}
+
 $node_publisher->safe_psql('postgres',
        "CREATE PUBLICATION tap_pub FOR ALL TABLES");