gistfile1.txt

no-lock patch:

pgbench=# explain (analyze,buffers) select * from big_table b inner join small_table s on b.i = s.i where b.date > '2015-11-30 15:25:00' and b.i = 1000001;                  
                                                                              QUERY PLAN                                                                              
----------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Nested Loop  (cost=0.00..16.94 rows=4 width=16) (actual time=0.057..0.060 rows=1 loops=1)
   Buffers: shared hit=8
   ->  Append  (cost=0.00..8.45 rows=2 width=12) (actual time=0.024..0.025 rows=1 loops=1)
         Buffers: shared hit=4
         ->  Seq Scan on big_table b  (cost=0.00..0.00 rows=1 width=12) (actual time=0.003..0.003 rows=0 loops=1)
               Filter: ((date > '2015-11-30 15:25:00'::timestamp without time zone) AND (i = 1000001))
         ->  Index Scan using idx_big_table_part_1 on big_table_part_1 b_1  (cost=0.42..8.45 rows=1 width=12) (actual time=0.019..0.020 rows=1 loops=1)
               Index Cond: (i = 1000001)
               Filter: (date > '2015-11-30 15:25:00'::timestamp without time zone)
               Buffers: shared hit=4
   ->  Materialize  (cost=0.00..8.45 rows=2 width=4) (actual time=0.031..0.032 rows=1 loops=1)
         Buffers: shared hit=4
         ->  Append  (cost=0.00..8.44 rows=2 width=4) (actual time=0.018..0.019 rows=1 loops=1)
               Buffers: shared hit=4
               ->  Seq Scan on small_table s  (cost=0.00..0.00 rows=1 width=4) (actual time=0.001..0.001 rows=0 loops=1)
                     Filter: (i = 1000001)
               ->  Index Only Scan using idx_small_table_part_3 on small_table_part_3 s_1  (cost=0.42..8.44 rows=1 width=4) (actual time=0.016..0.017 rows=1 loops=1)
                     Index Cond: (i = 1000001)
                     Heap Fetches: 1
                     Buffers: shared hit=4
 Planning time: 12.275 ms
 Execution time: 0.160 ms
(22 rows)

vanilla:

pgbench=# explain (analyze,buffers) select * from big_table b inner join small_table s on b.i = s.i where b.date > '2015-11-30 15:25:00' and b.i = 1000001;
                                                                              QUERY PLAN                                                                              
----------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Nested Loop  (cost=0.00..16.94 rows=4 width=16) (actual time=0.025..0.026 rows=1 loops=1)
   Buffers: shared hit=8
   ->  Append  (cost=0.00..8.45 rows=2 width=12) (actual time=0.013..0.013 rows=1 loops=1)
         Buffers: shared hit=4
         ->  Seq Scan on big_table b  (cost=0.00..0.00 rows=1 width=12) (actual time=0.003..0.003 rows=0 loops=1)
               Filter: ((date > '2015-11-30 15:25:00'::timestamp without time zone) AND (i = 1000001))
         ->  Index Scan using idx_big_table_part_1 on big_table_part_1 b_1  (cost=0.42..8.45 rows=1 width=12) (actual time=0.010..0.010 rows=1 loops=1)
               Index Cond: (i = 1000001)
               Filter: (date > '2015-11-30 15:25:00'::timestamp without time zone)
               Buffers: shared hit=4
   ->  Materialize  (cost=0.00..8.45 rows=2 width=4) (actual time=0.011..0.011 rows=1 loops=1)
         Buffers: shared hit=4
         ->  Append  (cost=0.00..8.44 rows=2 width=4) (actual time=0.007..0.007 rows=1 loops=1)
               Buffers: shared hit=4
               ->  Seq Scan on small_table s  (cost=0.00..0.00 rows=1 width=4) (actual time=0.001..0.001 rows=0 loops=1)
                     Filter: (i = 1000001)
               ->  Index Only Scan using idx_small_table_part_3 on small_table_part_3 s_1  (cost=0.42..8.44 rows=1 width=4) (actual time=0.006..0.006 rows=1 loops=1)
                     Index Cond: (i = 1000001)
                     Heap Fetches: 1
                     Buffers: shared hit=4
 Planning time: 36.212 ms
 Execution time: 0.089 ms
(22 rows)