SET search_path TO public;
-- query type 1
EXPLAIN (COSTS false) SELECT * FROM t1, t2 WHERE t1.id = t2.id;
              QUERY PLAN              
--------------------------------------
 Merge Join
   Merge Cond: (t1.id = t2.id)
   ->  Index Scan using t1_pkey on t1
   ->  Index Scan using t2_pkey on t2
(4 rows)

-- query type 2
EXPLAIN (COSTS false) SELECT * FROM t1, t4 WHERE t1.val < 10;
               QUERY PLAN                
-----------------------------------------
 Nested Loop
   ->  Bitmap Heap Scan on t1
         Recheck Cond: (val < 10)
         ->  Bitmap Index Scan on t1_val
               Index Cond: (val < 10)
   ->  Materialize
         ->  Seq Scan on t4
(7 rows)

-- query type 3
EXPLAIN (COSTS false) SELECT * FROM t3, t4 WHERE t3.id = t4.id AND t4.ctid = '(1,1)';
                 QUERY PLAN                  
---------------------------------------------
 Merge Join
   Merge Cond: (t3.id = t4.id)
   ->  Index Scan using t3_pkey on t3
   ->  Sort
         Sort Key: t4.id
         ->  Seq Scan on t4
               Filter: (ctid = '(1,1)'::tid)
(7 rows)

-- query type 4
EXPLAIN (COSTS false) SELECT * FROM t1, t2 WHERE t1.id = t2.id AND t1.ctid = '(1,1)';
               QUERY PLAN                
-----------------------------------------
 Nested Loop
   ->  Tid Scan on t1
         TID Cond: (ctid = '(1,1)'::tid)
   ->  Index Scan using t2_pkey on t2
         Index Cond: (id = t1.id)
(5 rows)

-- query type 5
EXPLAIN (COSTS false) SELECT * FROM t1, t3 WHERE t1.val = t3.val;
           QUERY PLAN           
--------------------------------
 Hash Join
   Hash Cond: (t1.val = t3.val)
   ->  Seq Scan on t1
   ->  Hash
         ->  Seq Scan on t3
(5 rows)

-- query type 6
EXPLAIN (COSTS false) SELECT * FROM t1, t2, t3, t4 WHERE t1.id = t2.id AND t1.id = t3.id AND t1.id = t4.id;
                    QUERY PLAN                    
--------------------------------------------------
 Nested Loop
   ->  Merge Join
         Merge Cond: (t1.id = t4.id)
         ->  Merge Join
               Merge Cond: (t1.id = t2.id)
               ->  Index Scan using t1_pkey on t1
               ->  Index Scan using t2_pkey on t2
         ->  Sort
               Sort Key: t4.id
               ->  Seq Scan on t4
   ->  Index Scan using t3_pkey on t3
         Index Cond: (id = t1.id)
(12 rows)