Subject: [PATCH] Add test for REPACK CONCURRENTLY with concurrent modifications
---
Index: contrib/amcheck/t/007_repack_concurrently_mvcc.pl
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/contrib/amcheck/t/007_repack_concurrently_mvcc.pl b/contrib/amcheck/t/007_repack_concurrently_mvcc.pl
new file mode 100644
--- /dev/null	(date 1756650098221)
+++ b/contrib/amcheck/t/007_repack_concurrently_mvcc.pl	(date 1756650098221)
@@ -0,0 +1,94 @@
+
+# Copyright (c) 2021-2025, PostgreSQL Global Development Group
+
+# Test REPACK CONCURRENTLY with concurrent modifications
+use strict;
+use warnings FATAL => 'all';
+
+use PostgreSQL::Test::Cluster;
+use PostgreSQL::Test::Utils;
+
+use Test::More;
+
+my $node;
+
+#
+# Test set-up
+#
+$node = PostgreSQL::Test::Cluster->new('CIC_test');
+$node->init;
+$node->append_conf('postgresql.conf',
+	'lock_timeout = ' . (1000 * $PostgreSQL::Test::Utils::timeout_default));
+$node->append_conf('postgresql.conf', 'autovacuum=off');
+$node->append_conf(
+	'postgresql.conf', qq(
+wal_level = logical
+));
+$node->start;
+$node->safe_psql('postgres', q(CREATE EXTENSION amcheck));
+$node->safe_psql('postgres', q(CREATE TABLE tbl1(i int PRIMARY KEY, j int)));
+$node->safe_psql('postgres', q(CREATE TABLE tbl2(i int PRIMARY KEY, j int)));
+
+
+# Insert 100 rows into tbl1
+$node->safe_psql('postgres', q(
+    INSERT INTO tbl1 SELECT i, i % 100 FROM generate_series(1,100) i
+));
+
+# Insert 100 rows into tbl2
+$node->safe_psql('postgres', q(
+    INSERT INTO tbl2 SELECT i, i % 100 FROM generate_series(1,100) i
+));
+
+
+# Insert 100 rows into tbl1
+$node->safe_psql('postgres', q(
+	CREATE OR REPLACE FUNCTION log_raise(i int, j1 int, j2 int) RETURNS VOID AS $$
+	BEGIN
+	  RAISE NOTICE 'ERROR i=% j1=% j2=%', i, j1, j2;
+	END;$$ LANGUAGE plpgsql;
+));
+
+$node->safe_psql('postgres', q(CREATE UNLOGGED SEQUENCE in_row_repack START 1 INCREMENT 1;));
+$node->safe_psql('postgres', q(SELECT nextval('in_row_repack');));
+
+
+$node->pgbench(
+'--no-vacuum --client=10 --jobs=4 --exit-on-abort --transactions=25000',
+0,
+[qr{actually processed}],
+[qr{^$}],
+'concurrent operations with REPACK CONCURRENTLY',
+{
+	'concurrent_ops' => q(
+		SELECT pg_try_advisory_lock(42)::integer AS gotlock \gset
+		\if :gotlock
+			SELECT nextval('in_row_repack') AS last_value \gset
+			\if :last_value = 2
+				REPACK (CONCURRENTLY) tbl2 USING INDEX tbl2_pkey;
+				\sleep 10 ms
+			\endif
+			SELECT pg_advisory_unlock(42);
+		\else
+			\set num random(1, 100)
+			BEGIN;
+			UPDATE tbl1 SET j = j + 1 WHERE i = :num;
+			UPDATE tbl2 SET j = j + 1 WHERE i = :num;
+			COMMIT;
+			SELECT setval('in_row_repack', 1);
+
+			SELECT COUNT(*) AS suspect FROM (SELECT * FROM tbl1 LEFT OUTER JOIN tbl2 ON tbl1.i = tbl2.i WHERE tbl1.j != tbl2.j) as X  \gset p_
+			\if :p_suspect != 0
+				SELECT pg_advisory_lock(42); -- make sure we have not any concurrent repack
+				SELECT COUNT(*) AS fatal FROM (SELECT log_raise(tbl1.i, tbl1.j, tbl2.j) FROM tbl1 LEFT OUTER JOIN tbl2 ON tbl1.i = tbl2.i WHERE tbl1.j != tbl2.j) as X  \gset p_
+				\if :p_fatal != 0
+					SELECT :p_fatal / 0;
+				\endif
+				SELECT pg_advisory_unlock(42);
+			\endif
+		\endif
+	)
+});
+
+$node->stop;
+done_testing();
Index: contrib/amcheck/meson.build
IDEA additional info:
Subsystem: com.intellij.openapi.diff.impl.patch.CharsetEP
<+>UTF-8
===================================================================
diff --git a/contrib/amcheck/meson.build b/contrib/amcheck/meson.build
--- a/contrib/amcheck/meson.build	(revision 911e274d320364685721d5d84d8013f2f510e5aa)
+++ b/contrib/amcheck/meson.build	(date 1756649361369)
@@ -50,6 +50,7 @@
       't/004_verify_nbtree_unique.pl',
       't/005_pitr.pl',
       't/006_verify_gin.pl',
+      't/007_repack_concurrently_mvcc.pl',
     ],
   },
 }