0001-add-vacuum-extending-freeze-test.patch

diff --git a/src/test/recovery/t/052_vacuum_extending_freeze_test.pl b/src/test/recovery/t/052_vacuum_extending_freeze_test.pl
new file mode 100644
index 00000000000..384e123381f
--- /dev/null
+++ b/src/test/recovery/t/052_vacuum_extending_freeze_test.pl
@@ -0,0 +1,215 @@
+# Copyright (c) 2025 PostgreSQL Global Development Group
+#
+# Test cumulative vacuum stats system using TAP
+#
+# In short, this test validates the correctness and stability of cumulative
+# vacuum statistics accounting around freezing, visibility, and revision
+# tracking across VACUUM and backend operations.
+
+use strict;
+use warnings;
+use PostgreSQL::Test::Cluster;
+use PostgreSQL::Test::Utils;
+use Test::More;
+
+plan tests => 10;
+
+#------------------------------------------------------------------------------
+# Test cluster setup
+#------------------------------------------------------------------------------
+
+my $node = PostgreSQL::Test::Cluster->new('vacuum_extending_freeze_test');
+$node->init;
+
+# Configure the server for aggressive freezing behavior used by the test
+$node->append_conf('postgresql.conf', q{
+	log_min_messages = notice
+    vacuum_freeze_min_age = 0
+    vacuum_freeze_table_age = 0
+});
+
+$node->start();
+
+#------------------------------------------------------------------------------
+# Database creation and initialization
+#------------------------------------------------------------------------------
+
+$node->safe_psql('postgres', q{
+	CREATE DATABASE statistic_vacuum_database_regression;
+});
+
+# Main test database name
+my $dbname = 'statistic_vacuum_database_regression';
+
+# Enable necessary settings and force the stats collector to flush next
+$node->safe_psql($dbname, q{
+    SET track_functions = 'all';
+    SELECT pg_stat_force_next_flush();
+});
+
+#------------------------------------------------------------------------------
+# Timing parameters for polling loops
+#------------------------------------------------------------------------------
+
+my $timeout    = 30;     # overall wait timeout in seconds
+my $interval   = 0.015;  # poll interval in seconds (15 ms)
+my $start_time = time();
+my $updated    = 0;
+
+# Polls statistics until the named columns exceed the provided
+# baseline values or until timeout.
+#
+# run_vacuum is a boolean (0 or 1) means we need to fetch frozen and visible pages
+# from pg_class table, otherwise we need to fetch frozen and visible pages from pg_stat_all_tables table.
+# Returns: 1 if the condition is met before timeout, 0 otherwise.
+sub wait_for_vacuum_stats {
+    my (%args) = @_;
+    my $run_vacuum = ($args{run_vacuum} or 0);
+    my $result_query;
+    my $sql;
+
+    my $start = time();
+    while ((time() - $start) < $timeout) {
+
+        if ($run_vacuum) {
+            $node->safe_psql($dbname, 'VACUUM vestat');
+
+            $sql = "
+            SELECT relallfrozen > 0
+                AND relallvisible > 0
+                FROM pg_class c
+                WHERE c.relname = 'vestat'";
+        }
+        else {
+            $sql = "
+            SELECT rev_all_frozen_pages > 0
+                AND rev_all_visible_pages > 0
+                FROM pg_stat_all_tables
+                WHERE relname = 'vestat'";
+        }
+
+        $result_query = $node->safe_psql($dbname, $sql);
+
+        return 1 if (defined $result_query && $result_query eq 't');
+
+        # sub-second sleep
+        sleep($interval);
+    }
+
+    return 0;
+}
+
+#------------------------------------------------------------------------------
+# Variables to hold vacuum statistics snapshots for comparisons
+#------------------------------------------------------------------------------
+
+my $relallvisible = 0;
+my $relallfrozen = 0;
+
+my $relallvisible_prev = 0;
+my $relallfrozen_prev = 0;
+
+my $rev_all_frozen_pages = 0;
+my $rev_all_visible_pages = 0;
+
+my $res;
+
+#------------------------------------------------------------------------------
+# fetch_vacuum_stats
+#
+# Loads current values of the relevant vacuum counters for the test table
+# into the package-level variables above so tests can compare later.
+#------------------------------------------------------------------------------
+
+sub fetch_vacuum_stats {
+    my $base_statistics = $node->safe_psql(
+        $dbname,
+        "SELECT c.relallvisible, c.relallfrozen,
+                rev_all_visible_pages, rev_all_frozen_pages
+           FROM pg_class c
+           LEFT JOIN pg_stat_all_tables s ON s.relid = c.oid
+          WHERE c.relname = 'vestat';"
+    );
+
+    $base_statistics =~ s/\s*\|\s*/ /g;   # transform " | " into space
+    ($relallvisible, $relallfrozen, $rev_all_visible_pages, $rev_all_frozen_pages)
+        = split /\s+/, $base_statistics;
+}
+
+#------------------------------------------------------------------------------
+# Test 1: Create test table, populate it and run an initial vacuum to force freezing
+#------------------------------------------------------------------------------
+
+$node->safe_psql($dbname, q{
+	SELECT pg_stat_force_next_flush();
+	CREATE TABLE vestat (x int)
+		WITH (autovacuum_enabled = off, fillfactor = 70);
+	INSERT INTO vestat SELECT x FROM generate_series(1, 5000) AS g(x);
+	ANALYZE vestat;
+});
+
+# Poll the stats view until the expected deltas appear or timeout.
+$updated = wait_for_vacuum_stats(run_vacuum => 1);
+
+ok($updated,
+   'vacuum stats updated after vacuuming the table (relallfrozen and relallvisible advanced)')
+  or diag "Timeout waiting for pg_stats_vacuum_tables to update after $timeout seconds during vacuum";
+
+#------------------------------------------------------------------------------
+# Snapshot current statistics for later comparison
+#------------------------------------------------------------------------------
+
+fetch_vacuum_stats();
+
+#------------------------------------------------------------------------------
+# Verify initial statistics after vacuum
+#------------------------------------------------------------------------------
+ok($relallfrozen > $relallfrozen_prev, 'relallfrozen has increased');
+ok($relallvisible > $relallvisible_prev, 'relallvisible has increased');
+ok($rev_all_frozen_pages == 0, 'rev_all_frozen_pages stay the same');
+ok($rev_all_visible_pages == 0, 'rev_all_visible_pages stay the same');
+
+#------------------------------------------------------------------------------
+# Test 2: Trigger backend updates
+# Backend activity should reset per-page visibility/freeze marks and increment revision counters
+#------------------------------------------------------------------------------
+$relallfrozen_prev = $relallfrozen;
+$relallvisible_prev = $relallvisible;
+
+$node->safe_psql($dbname, q{
+    UPDATE vestat SET x = x + 1001;
+});
+
+$node->safe_psql($dbname, 'SELECT pg_stat_force_next_flush()');
+
+# Poll until stats update or timeout.
+$updated = wait_for_vacuum_stats(run_vacuum => 0);
+ok($updated,
+   'vacuum stats updated after backend tuple updates (rev_all_frozen_pages and rev_all_visible_pages advanced)')
+  or diag "Timeout waiting for pg_stats_vacuum_* update after $timeout seconds";
+
+#------------------------------------------------------------------------------
+# Snapshot current statistics for later comparison
+#------------------------------------------------------------------------------
+
+fetch_vacuum_stats();
+
+#------------------------------------------------------------------------------
+# Check updated statistics after backend activity
+#------------------------------------------------------------------------------
+
+ok($relallfrozen == $relallfrozen_prev, 'relallfrozen stay the same');
+ok($relallvisible == $relallvisible_prev, 'relallvisible stay the same');
+ok($rev_all_frozen_pages > 0, 'rev_all_frozen_pages has increased');
+ok($rev_all_visible_pages > 0, 'rev_all_visible_pages has increased');
+
+#------------------------------------------------------------------------------
+# Cleanup
+#------------------------------------------------------------------------------
+
+$node->safe_psql('postgres', q{
+	DROP DATABASE statistic_vacuum_database_regression;
+});
+
+$node->stop;
+done_testing();
-- 
2.39.5 (Apple Git-154)