From 9565d27b351a8a6fce57eda0c4218028793981e7 Mon Sep 17 00:00:00 2001
From: Rui Zhao <zhaorui126@gmail.com>
Date: Tue, 15 Sep 2026 00:45:53 +0800
Subject: [PATCH 6/7] Check oid8 TOAST values past 2^32 with amcheck

The amcheck regression tests cover TOAST relations with oid8 chunk IDs,
but their OID counter is young, so the IDs they see fit in four bytes.
Move the counter past 2^32 in a TAP test and run verify_heapam() on a
table with such values and on its TOAST table, and bt_index_parent_check()
on the TOAST index, before and after VACUUM.
---
 contrib/amcheck/meson.build                |  1 +
 contrib/amcheck/t/007_verify_oid8_toast.pl | 87 ++++++++++++++++++++++
 2 files changed, 88 insertions(+)
 create mode 100644 contrib/amcheck/t/007_verify_oid8_toast.pl

diff --git a/contrib/amcheck/meson.build b/contrib/amcheck/meson.build
index d5137ef691d..269529d0108 100644
--- a/contrib/amcheck/meson.build
+++ b/contrib/amcheck/meson.build
@@ -50,6 +50,7 @@ tests += {
       't/004_verify_nbtree_unique.pl',
       't/005_pitr.pl',
       't/006_verify_gin.pl',
+      't/007_verify_oid8_toast.pl',
     ],
   },
 }
diff --git a/contrib/amcheck/t/007_verify_oid8_toast.pl b/contrib/amcheck/t/007_verify_oid8_toast.pl
new file mode 100644
index 00000000000..b5f4c337fc5
--- /dev/null
+++ b/contrib/amcheck/t/007_verify_oid8_toast.pl
@@ -0,0 +1,87 @@
+# Copyright (c) 2026, PostgreSQL Global Development Group
+#
+# Check a table whose TOAST values have oid8 IDs past 2^32, on the heap
+# side and on the TOAST side.  The amcheck regression tests use a young
+# OID counter, so their oid8 values have IDs that fit in four bytes.
+use strict;
+use warnings FATAL => 'all';
+
+use PostgreSQL::Test::Cluster;
+use PostgreSQL::Test::Utils;
+
+use Test::More;
+
+my $next_oid = '4295067296';    # 2^32 + 100000
+
+my $node = PostgreSQL::Test::Cluster->new('test');
+$node->init;
+command_ok(
+	[ 'pg_resetwal', '--next-oid' => $next_oid, $node->data_dir ],
+	'set an 8-byte OID counter');
+$node->append_conf('postgresql.conf', 'autovacuum = off');
+$node->start;
+$node->safe_psql('postgres', 'CREATE EXTENSION amcheck');
+
+# Out-of-line values, uncompressed and compressed, some of them replaced
+# or deleted so that the TOAST table holds dead chunks as well.  The
+# compressed values are large enough to stay out of line once compressed.
+$node->safe_psql(
+	'postgres', q(
+CREATE TABLE toast_oid8 (a int PRIMARY KEY, b text)
+  WITH (toast_value_type = 'oid8');
+ALTER TABLE toast_oid8 ALTER COLUMN b SET STORAGE EXTERNAL;
+INSERT INTO toast_oid8
+  SELECT gs, repeat(md5(gs::text), 400) FROM generate_series(1, 5) gs;
+ALTER TABLE toast_oid8 ALTER COLUMN b SET STORAGE EXTENDED;
+INSERT INTO toast_oid8
+  SELECT gs, repeat(md5(gs::text), 20000) FROM generate_series(6, 10) gs;
+UPDATE toast_oid8 SET b = repeat(md5('plugh'), 20000) WHERE a IN (3, 8);
+DELETE FROM toast_oid8 WHERE a IN (5, 10);
+));
+
+my $toast_table = $node->safe_psql('postgres',
+	"SELECT reltoastrelid::regclass FROM pg_class WHERE relname = 'toast_oid8'"
+);
+my $toast_index = $node->safe_psql('postgres',
+	"SELECT indexrelid::regclass FROM pg_index WHERE indrelid = '$toast_table'::regclass"
+);
+
+is( $node->safe_psql(
+		'postgres',
+		"SELECT count(*), count(pg_column_toast_chunk_id(b)),
+		        min(pg_column_toast_chunk_id(b)) > '$next_oid'::oid8,
+		        count(*) FILTER (WHERE pg_column_compression(b) IS NOT NULL)
+		   FROM toast_oid8"),
+	'8|8|t|5',
+	'all values are out of line, with IDs past 2^32');
+
+sub check_all
+{
+	my ($stage) = @_;
+
+	is( $node->safe_psql(
+			'postgres',
+			"SELECT count(*) FROM verify_heapam('toast_oid8', check_toast := true)"
+		),
+		'0',
+		"verify_heapam reports nothing for the table and its TOAST values $stage"
+	);
+	is( $node->safe_psql(
+			'postgres', "SELECT count(*) FROM verify_heapam('$toast_table')"),
+		'0',
+		"verify_heapam reports nothing for the TOAST table $stage");
+	is( $node->safe_psql(
+			'postgres',
+			"SELECT bt_index_parent_check('$toast_index', heapallindexed => true)"
+		),
+		'',
+		"bt_index_parent_check passes on the TOAST index $stage");
+}
+
+check_all('with dead chunks');
+$node->safe_psql('postgres', 'VACUUM toast_oid8');
+check_all('after VACUUM');
+
+$node->stop;
+
+done_testing();
-- 
2.43.7