From 1cb78809a245edc7831078348243356d997cbdda Mon Sep 17 00:00:00 2001
From: Vignesh C <vignesh21@gmail.com>
Date: Mon, 20 Nov 2023 14:40:22 +0530
Subject: [PATCH v3] Specify parentheses for tablesync worker copy command only
 if the table has some column.

Copy command was specifying parentheses for tables having no columns too,
fixed it by specifying the parentheses and columns only if table has
some columns.
---
 src/backend/replication/logical/tablesync.c | 28 +++++++++++++--------
 src/test/subscription/t/001_rep_changes.pl  | 17 ++++++++++++-
 2 files changed, 34 insertions(+), 11 deletions(-)

diff --git a/src/backend/replication/logical/tablesync.c b/src/backend/replication/logical/tablesync.c
index 37a0abe2f4..87785c6202 100644
--- a/src/backend/replication/logical/tablesync.c
+++ b/src/backend/replication/logical/tablesync.c
@@ -1124,22 +1124,30 @@ copy_table(Relation rel)
 	/* Regular table with no row filter */
 	if (lrel.relkind == RELKIND_RELATION && qual == NIL)
 	{
-		appendStringInfo(&cmd, "COPY %s (",
+		appendStringInfo(&cmd, "COPY %s",
 						 quote_qualified_identifier(lrel.nspname, lrel.relname));
 
-		/*
-		 * XXX Do we need to list the columns in all cases? Maybe we're
-		 * replicating all columns?
-		 */
-		for (int i = 0; i < lrel.natts; i++)
+		/* If the table has columns, then specify the columns */
+		if (lrel.natts)
 		{
-			if (i > 0)
-				appendStringInfoString(&cmd, ", ");
+			appendStringInfoString(&cmd, " (");
 
-			appendStringInfoString(&cmd, quote_identifier(lrel.attnames[i]));
+			/*
+			* XXX Do we need to list the columns in all cases? Maybe we're
+			* replicating all columns?
+			*/
+			for (int i = 0; i < lrel.natts; i++)
+			{
+				if (i > 0)
+					appendStringInfoString(&cmd, ", ");
+
+				appendStringInfoString(&cmd, quote_identifier(lrel.attnames[i]));
+			}
+
+			appendStringInfoString(&cmd, ")");
 		}
 
-		appendStringInfoString(&cmd, ") TO STDOUT");
+		appendStringInfoString(&cmd, " TO STDOUT");
 	}
 	else
 	{
diff --git a/src/test/subscription/t/001_rep_changes.pl b/src/test/subscription/t/001_rep_changes.pl
index 87d44f634f..e49da00b29 100644
--- a/src/test/subscription/t/001_rep_changes.pl
+++ b/src/test/subscription/t/001_rep_changes.pl
@@ -57,6 +57,11 @@ $node_publisher->safe_psql('postgres',
 	"CREATE INDEX idx_no_replidentity_index ON tab_no_replidentity_index(c1)"
 );
 
+# Replicate the changes without columns
+$node_publisher->safe_psql('postgres', "CREATE TABLE tab_no_col()");
+$node_publisher->safe_psql('postgres',
+	"INSERT INTO tab_no_col default VALUES");
+
 # Setup structure on subscriber
 $node_subscriber->safe_psql('postgres', "CREATE TABLE tab_notrep (a int)");
 $node_subscriber->safe_psql('postgres', "CREATE TABLE tab_ins (a int)");
@@ -87,13 +92,16 @@ $node_subscriber->safe_psql('postgres',
 	"CREATE INDEX idx_no_replidentity_index ON tab_no_replidentity_index(c1)"
 );
 
+# replication of the table without columns
+$node_subscriber->safe_psql('postgres', "CREATE TABLE tab_no_col()");
+
 # Setup logical replication
 my $publisher_connstr = $node_publisher->connstr . ' dbname=postgres';
 $node_publisher->safe_psql('postgres', "CREATE PUBLICATION tap_pub");
 $node_publisher->safe_psql('postgres',
 	"CREATE PUBLICATION tap_pub_ins_only WITH (publish = insert)");
 $node_publisher->safe_psql('postgres',
-	"ALTER PUBLICATION tap_pub ADD TABLE tab_rep, tab_full, tab_full2, tab_mixed, tab_include, tab_nothing, tab_full_pk, tab_no_replidentity_index"
+	"ALTER PUBLICATION tap_pub ADD TABLE tab_rep, tab_full, tab_full2, tab_mixed, tab_include, tab_nothing, tab_full_pk, tab_no_replidentity_index, tab_no_col"
 );
 $node_publisher->safe_psql('postgres',
 	"ALTER PUBLICATION tap_pub_ins_only ADD TABLE tab_ins");
@@ -141,6 +149,9 @@ $node_publisher->safe_psql('postgres', "UPDATE tab_include SET a = -a");
 $node_publisher->safe_psql('postgres',
 	"INSERT INTO tab_no_replidentity_index VALUES(1)");
 
+$node_publisher->safe_psql('postgres',
+	"INSERT INTO tab_no_col default VALUES");
+
 $node_publisher->wait_for_catchup('tap_sub');
 
 $result = $node_subscriber->safe_psql('postgres',
@@ -169,6 +180,10 @@ is( $node_subscriber->safe_psql(
 	1,
 	"value replicated to subscriber without replica identity index");
 
+$result =
+  $node_subscriber->safe_psql('postgres', "SELECT count(*) FROM tab_no_col");
+is($result, qq(2), 'check replicated changes for table having no columns');
+
 # insert some duplicate rows
 $node_publisher->safe_psql('postgres',
 	"INSERT INTO tab_full SELECT generate_series(1,10)");
-- 
2.34.1