diff --git a/src/backend/access/index/indexam.c b/src/backend/access/index/indexam.c
index ce94649..b9e519a 100644
--- a/src/backend/access/index/indexam.c
+++ b/src/backend/access/index/indexam.c
@@ -671,14 +671,19 @@ index_bulk_delete(IndexVacuumInfo *info,
 				  void *callback_state)
 {
 	Relation	indexRelation = info->index;
-	FmgrInfo   *procedure;
+	RegProcedure procOid;
+	FmgrInfo	procedure;
 	IndexBulkDeleteResult *result;
 
 	RELATION_CHECKS;
-	GET_REL_PROCEDURE(ambulkdelete);
+
+	procOid = indexRelation->rd_am->ambulkdelete;
+	if (!RegProcedureIsValid(procOid))
+		elog(ERROR, "invalid ambulkdelete regproc");
+	fmgr_info(procOid, &procedure);
 
 	result = (IndexBulkDeleteResult *)
-		DatumGetPointer(FunctionCall4(procedure,
+		DatumGetPointer(FunctionCall4(&procedure,
 									  PointerGetDatum(info),
 									  PointerGetDatum(stats),
 									  PointerGetDatum((Pointer) callback),
@@ -698,14 +703,19 @@ index_vacuum_cleanup(IndexVacuumInfo *info,
 					 IndexBulkDeleteResult *stats)
 {
 	Relation	indexRelation = info->index;
-	FmgrInfo   *procedure;
+	RegProcedure procOid;
+	FmgrInfo	procedure;
 	IndexBulkDeleteResult *result;
 
 	RELATION_CHECKS;
-	GET_REL_PROCEDURE(amvacuumcleanup);
+
+	procOid = indexRelation->rd_am->amvacuumcleanup;
+	if (!RegProcedureIsValid(procOid))
+		elog(ERROR, "invalid amvacuumcleanup regproc");
+	fmgr_info(procOid, &procedure);
 
 	result = (IndexBulkDeleteResult *)
-		DatumGetPointer(FunctionCall2(procedure,
+		DatumGetPointer(FunctionCall2(&procedure,
 									  PointerGetDatum(info),
 									  PointerGetDatum(stats)));
 
diff --git a/src/include/utils/rel.h b/src/include/utils/rel.h
index a4daf77..05f2011 100644
--- a/src/include/utils/rel.h
+++ b/src/include/utils/rel.h
@@ -47,8 +47,8 @@ typedef LockInfoData *LockInfo;
 
 
 /*
- * Cached lookup information for the index access method functions defined
- * by the pg_am row associated with an index relation.
+ * Cached lookup information for the frequently used index access method
+ * functions, defined by the pg_am row associated with an index relation.
  */
 typedef struct RelationAmInfo
 {
@@ -60,13 +60,7 @@ typedef struct RelationAmInfo
 	FmgrInfo	amendscan;
 	FmgrInfo	ammarkpos;
 	FmgrInfo	amrestrpos;
-	FmgrInfo	ambuild;
-	FmgrInfo	ambuildempty;
-	FmgrInfo	ambulkdelete;
-	FmgrInfo	amvacuumcleanup;
 	FmgrInfo	amcanreturn;
-	FmgrInfo	amcostestimate;
-	FmgrInfo	amoptions;
 } RelationAmInfo;