From bca4cfd1b8837ced9b74a04267861cac8003fbc6 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter@eisentraut.org>
Date: Wed, 12 Mar 2025 13:45:39 +0100
Subject: [PATCH v21.2 1/4] Add get_opfamily_method()

---
 src/backend/utils/cache/lsyscache.c | 22 ++++++++++++++++++++++
 src/include/utils/lsyscache.h       |  1 +
 2 files changed, 23 insertions(+)

diff --git a/src/backend/utils/cache/lsyscache.c b/src/backend/utils/cache/lsyscache.c
index 80c5a3fcfb7..9f7c0315052 100644
--- a/src/backend/utils/cache/lsyscache.c
+++ b/src/backend/utils/cache/lsyscache.c
@@ -1288,6 +1288,28 @@ get_opclass_method(Oid opclass)
 
 /*				---------- OPFAMILY CACHE ----------					 */
 
+/*
+ * get_opfamily_method
+ *
+ *		Returns the OID of the index access method the opfamily is for.
+ */
+Oid
+get_opfamily_method(Oid opfid)
+{
+	HeapTuple       tp;
+	Form_pg_opfamily opfform;
+	Oid				result;
+
+	tp = SearchSysCache1(OPFAMILYOID, ObjectIdGetDatum(opfid));
+	if (!HeapTupleIsValid(tp))
+		elog(ERROR, "cache lookup failed for operator family %u", opfid);
+	opfform = (Form_pg_opfamily) GETSTRUCT(tp);
+
+	result = opfform->opfmethod;
+	ReleaseSysCache(tp);
+	return result;
+}
+
 char *
 get_opfamily_name(Oid opfid, bool missing_ok)
 {
diff --git a/src/include/utils/lsyscache.h b/src/include/utils/lsyscache.h
index 6fab7aa6009..271eac2f0e1 100644
--- a/src/include/utils/lsyscache.h
+++ b/src/include/utils/lsyscache.h
@@ -108,6 +108,7 @@ extern Oid	get_opclass_input_type(Oid opclass);
 extern bool get_opclass_opfamily_and_input_type(Oid opclass,
 												Oid *opfamily, Oid *opcintype);
 extern Oid	get_opclass_method(Oid opclass);
+extern Oid	get_opfamily_method(Oid opfid);
 extern char *get_opfamily_name(Oid opfid, bool missing_ok);
 extern RegProcedure get_opcode(Oid opno);
 extern char *get_opname(Oid opno);
-- 
2.48.1