QUERY PLAN                            
-----------------------------------------------------------------
 Nested Loop  (cost=xxx rows=1 width=88)
   Join Filter: (t1.c1 = t2.c1)
   ->  Function Scan on f1 t1  (cost=xxx rows=1 width=44)
   ->  Function Scan on f1 t2  (cost=xxx rows=1 width=44)
(4 rows)

                           QUERY PLAN                            
-----------------------------------------------------------------
 Nested Loop  (cost=xxx rows=1 width=88)
   Join Filter: (t1.c1 = t2.c1)
   ->  Function Scan on f1 t1  (cost=xxx rows=1 width=44)
   ->  Function Scan on f1 t2  (cost=xxx rows=1 width=44)
(4 rows)