QUERY PLAN                                 
---------------------------------------------------------------------------
 Merge Join  (cost=xxx rows=100 width=29)
   Merge Cond: (t1.c1 = t1_1.c1)
   ->  Index Scan using t1_i1 on t1  (cost=xxx rows=1000 width=15)
   ->  Sort  (cost=xxx rows=100 width=14)
         Sort Key: t1_1.c1
         ->  Seq Scan on t1 t1_1  (cost=xxx rows=100 width=14)
(6 rows)

                                QUERY PLAN                                 
---------------------------------------------------------------------------
 Merge Join  (cost=xxx rows=100 width=29)
   Merge Cond: (t1.c1 = t1_1.c1)
   ->  Index Scan using t1_i1 on t1  (cost=xxx rows=1000 width=15)
   ->  Sort  (cost=xxx rows=100 width=14)
         Sort Key: t1_1.c1
         ->  Seq Scan on t1 t1_1  (cost=xxx rows=100 width=14)
(6 rows)

                                QUERY PLAN                                 
---------------------------------------------------------------------------
 Merge Join  (cost=xxx rows=100 width=29)
   Merge Cond: (t1.c1 = t1_1.c1)
   ->  Index Scan using t1_i1 on t1  (cost=xxx rows=1000 width=15)
   ->  Sort  (cost=xxx rows=100 width=14)
         Sort Key: t1_1.c1
         ->  Seq Scan on t1 t1_1  (cost=xxx rows=100 width=14)
(6 rows)

                                QUERY PLAN                                 
---------------------------------------------------------------------------
 Merge Join  (cost=xxx rows=100 width=29)
   Merge Cond: (t1.c1 = s2t1.c1)
   ->  Index Scan using t1_i1 on t1  (cost=xxx rows=1000 width=15)
   ->  Sort  (cost=xxx rows=100 width=14)
         Sort Key: s2t1.c1
         ->  Seq Scan on t1 s2t1  (cost=xxx rows=100 width=14)
(6 rows)

                                QUERY PLAN                                 
---------------------------------------------------------------------------
 Merge Join  (cost=xxx rows=1 width=29)
   Merge Cond: (t1.c1 = s2t1.c1)
   ->  Index Scan using t1_i1 on t1  (cost=xxx rows=1000 width=15)
   ->  Sort  (cost=xxx rows=100 width=14)
         Sort Key: s2t1.c1
         ->  Seq Scan on t1 s2t1  (cost=xxx rows=100 width=14)
(6 rows)