From 51b5d084bb6065a5d908a4e71fd4dcedf0d2f993 Mon Sep 17 00:00:00 2001
From: Mark Wong <mark.wong@enterprisedb.com>
Date: Thu, 29 Jan 2026 15:47:50 -0800
Subject: [PATCH v3 1/7] Track retired system procedures in pg_retired.dat

System procedures may be removed from time to time.  Keep track of
previously used OIDs to prevent potential conflicts from reusing OIDs
after an upgrade.
---
 src/include/catalog/pg_retired.dat   | 20 ++++++++++++++++++++
 src/include/catalog/renumber_oids.pl |  9 +++++++++
 src/include/catalog/unused_oids      |  7 +++++++
 3 files changed, 36 insertions(+)
 create mode 100644 src/include/catalog/pg_retired.dat

diff --git a/src/include/catalog/pg_retired.dat b/src/include/catalog/pg_retired.dat
new file mode 100644
index 00000000000..413b68ad1cd
--- /dev/null
+++ b/src/include/catalog/pg_retired.dat
@@ -0,0 +1,20 @@
+#----------------------------------------------------------------------
+#
+# pg_retired.dat
+#    Entries that have been removed from pg_proc.dat with OIDs that are
+#    are not to be reused.
+#
+# Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group
+# Portions Copyright (c) 1994, Regents of the University of California
+#
+# src/include/catalog/pg_retired.dat
+#
+#----------------------------------------------------------------------
+
+[
+
+# What's primarily important here is knowing which OIDs are not to be reused.
+# At the same time, it may be good to be reminded what procedure was associated
+# with it.
+
+]
diff --git a/src/include/catalog/renumber_oids.pl b/src/include/catalog/renumber_oids.pl
index f6e25d0f1e1..7489be02a50 100755
--- a/src/include/catalog/renumber_oids.pl
+++ b/src/include/catalog/renumber_oids.pl
@@ -68,6 +68,15 @@ my $oids = Catalog::FindAllOidsFromHeaders(@header_files);
 my %oidhash;
 @oidhash{@$oids} = undef;
 
+# Also include OIDs listed in pg_retired.dat to prevent new OIDs to be mapped
+# to OIDs that have been retired.
+my $retired_data = Catalog::ParseData('pg_retired.dat', undef, 0);
+foreach my $row (@$retired_data)
+{
+	$oidhash{ $row->{oid} } = undef
+	  if ref $row eq 'HASH' && defined $row->{oid};
+}
+
 # Select new OIDs for existing OIDs in the mapped range.
 # We do this first so that we preserve the ordering of the mapped OIDs
 # (for reproducibility's sake), and so that if we fail due to running out
diff --git a/src/include/catalog/unused_oids b/src/include/catalog/unused_oids
index 147fba5e209..aeb485d9b5e 100755
--- a/src/include/catalog/unused_oids
+++ b/src/include/catalog/unused_oids
@@ -32,6 +32,13 @@ my @input_files = glob("pg_*.h");
 
 my $oids = Catalog::FindAllOidsFromHeaders(@input_files);
 
+# Also exclude OIDs listed in pg_retired.dat
+my $retired_data = Catalog::ParseData('pg_retired.dat', undef, 0);
+foreach my $row (@$retired_data)
+{
+	push @{$oids}, $row->{oid} if ref $row eq 'HASH' && defined $row->{oid};
+}
+
 # Also push FirstGenbkiObjectId to serve as a terminator for the last gap.
 my $FirstGenbkiObjectId =
   Catalog::FindDefinedSymbol('access/transam.h', '..', 'FirstGenbkiObjectId');
-- 
2.43.0