Postgres 15

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create table demo (num bigint primary key)

CREATE TABLE

insert into demo select generate_series(1,10000)

INSERT 0 10000

vacuum analyze demo

VACUUM

explain (analyze, buffers) 
select * from demo 
where num in (2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97)

QUERY PLAN

Index Only Scan using demo_pkey on demo  (cost=0.29..79.56 rows=25 width=8) (actual time=0.334..0.363 rows=25 loops=1)

  Index Cond: (num = ANY ('{2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97}'::bigint[]))

  Heap Fetches: 0

  Buffers: shared hit=54

Planning:

  Buffers: shared hit=26

Planning Time: 0.431 ms

Execution Time: 0.944 ms

EXPLAIN

explain (analyze, buffers) 
select * from demo 
where num=2 OR num=3 OR num=5 OR num=7 OR num=11 OR num=13 OR num=17 OR num=19 OR num=23 OR num=29 OR num=31 OR num=37 OR num=41 OR num=43 OR num=47 OR num=53 OR num=59 OR num=61 OR num=67 OR num=71 OR num=73 OR num=79 OR num=83 OR num=89 OR num=97

QUERY PLAN

Bitmap Heap Scan on demo  (cost=107.47..149.28 rows=25 width=8) (actual time=0.388..0.394 rows=25 loops=1)

  Recheck Cond: ((num = 2) OR (num = 3) OR (num = 5) OR (num = 7) OR (num = 11) OR (num = 13) OR (num = 17) OR (num = 19) OR (num = 23) OR (num = 29) OR (num = 31) OR (num = 37) OR (num = 41) OR (num = 43) OR (num = 47) OR (num = 53) OR (num = 59) OR (num = 61) OR (num = 67) OR (num = 71) OR (num = 73) OR (num = 79) OR (num = 83) OR (num = 89) OR (num = 97))

  Heap Blocks: exact=1

  Buffers: shared hit=54

  ->  BitmapOr  (cost=107.47..107.47 rows=25 width=0) (actual time=0.374..0.378 rows=0 loops=1)

        Buffers: shared hit=53

        ->  Bitmap Index Scan on demo_pkey  (cost=0.00..4.29 rows=1 width=0) (actual time=0.262..0.263 rows=1 loops=1)

              Index Cond: (num = 2)

              Buffers: shared hit=5

        ->  Bitmap Index Scan on demo_pkey  (cost=0.00..4.29 rows=1 width=0) (actual time=0.002..0.002 rows=1 loops=1)

              Index Cond: (num = 3)

              Buffers: shared hit=2

        ->  Bitmap Index Scan on demo_pkey  (cost=0.00..4.29 rows=1 width=0) (actual time=0.075..0.076 rows=1 loops=1)

              Index Cond: (num = 5)

              Buffers: shared hit=2

        ->  Bitmap Index Scan on demo_pkey  (cost=0.00..4.29 rows=1 width=0) (actual time=0.002..0.002 rows=1 loops=1)

              Index Cond: (num = 7)

              Buffers: shared hit=2

        ->  Bitmap Index Scan on demo_pkey  (cost=0.00..4.29 rows=1 width=0) (actual time=0.001..0.001 rows=1 loops=1)

              Index Cond: (num = 11)

              Buffers: shared hit=2

        ->  Bitmap Index Scan on demo_pkey  (cost=0.00..4.29 rows=1 width=0) (actual time=0.001..0.001 rows=1 loops=1)

              Index Cond: (num = 13)

              Buffers: shared hit=2

        ->  Bitmap Index Scan on demo_pkey  (cost=0.00..4.29 rows=1 width=0) (actual time=0.001..0.001 rows=1 loops=1)

              Index Cond: (num = 17)

              Buffers: shared hit=2

        ->  Bitmap Index Scan on demo_pkey  (cost=0.00..4.29 rows=1 width=0) (actual time=0.001..0.001 rows=1 loops=1)

              Index Cond: (num = 19)

              Buffers: shared hit=2

        ->  Bitmap Index Scan on demo_pkey  (cost=0.00..4.29 rows=1 width=0) (actual time=0.001..0.001 rows=1 loops=1)

              Index Cond: (num = 23)

              Buffers: shared hit=2

        ->  Bitmap Index Scan on demo_pkey  (cost=0.00..4.29 rows=1 width=0) (actual time=0.001..0.001 rows=1 loops=1)

              Index Cond: (num = 29)

              Buffers: shared hit=2

        ->  Bitmap Index Scan on demo_pkey  (cost=0.00..4.29 rows=1 width=0) (actual time=0.001..0.001 rows=1 loops=1)

              Index Cond: (num = 31)

              Buffers: shared hit=2

        ->  Bitmap Index Scan on demo_pkey  (cost=0.00..4.29 rows=1 width=0) (actual time=0.001..0.001 rows=1 loops=1)

              Index Cond: (num = 37)

              Buffers: shared hit=2

        ->  Bitmap Index Scan on demo_pkey  (cost=0.00..4.29 rows=1 width=0) (actual time=0.001..0.001 rows=1 loops=1)

              Index Cond: (num = 41)

              Buffers: shared hit=2

        ->  Bitmap Index Scan on demo_pkey  (cost=0.00..4.29 rows=1 width=0) (actual time=0.001..0.001 rows=1 loops=1)

              Index Cond: (num = 43)

              Buffers: shared hit=2

        ->  Bitmap Index Scan on demo_pkey  (cost=0.00..4.29 rows=1 width=0) (actual time=0.001..0.001 rows=1 loops=1)

              Index Cond: (num = 47)

              Buffers: shared hit=2

        ->  Bitmap Index Scan on demo_pkey  (cost=0.00..4.29 rows=1 width=0) (actual time=0.001..0.001 rows=1 loops=1)

              Index Cond: (num = 53)

              Buffers: shared hit=2

        ->  Bitmap Index Scan on demo_pkey  (cost=0.00..4.29 rows=1 width=0) (actual time=0.001..0.001 rows=1 loops=1)

              Index Cond: (num = 59)

              Buffers: shared hit=2

        ->  Bitmap Index Scan on demo_pkey  (cost=0.00..4.29 rows=1 width=0) (actual time=0.001..0.001 rows=1 loops=1)

              Index Cond: (num = 61)

              Buffers: shared hit=2

        ->  Bitmap Index Scan on demo_pkey  (cost=0.00..4.29 rows=1 width=0) (actual time=0.001..0.001 rows=1 loops=1)

              Index Cond: (num = 67)

              Buffers: shared hit=2

        ->  Bitmap Index Scan on demo_pkey  (cost=0.00..4.29 rows=1 width=0) (actual time=0.001..0.001 rows=1 loops=1)

              Index Cond: (num = 71)

              Buffers: shared hit=2

        ->  Bitmap Index Scan on demo_pkey  (cost=0.00..4.29 rows=1 width=0) (actual time=0.001..0.001 rows=1 loops=1)

              Index Cond: (num = 73)

              Buffers: shared hit=2

        ->  Bitmap Index Scan on demo_pkey  (cost=0.00..4.29 rows=1 width=0) (actual time=0.001..0.001 rows=1 loops=1)

              Index Cond: (num = 79)

              Buffers: shared hit=2

        ->  Bitmap Index Scan on demo_pkey  (cost=0.00..4.29 rows=1 width=0) (actual time=0.001..0.001 rows=1 loops=1)

              Index Cond: (num = 83)

              Buffers: shared hit=2

        ->  Bitmap Index Scan on demo_pkey  (cost=0.00..4.29 rows=1 width=0) (actual time=0.001..0.001 rows=1 loops=1)

              Index Cond: (num = 89)

              Buffers: shared hit=2

        ->  Bitmap Index Scan on demo_pkey  (cost=0.00..4.29 rows=1 width=0) (actual time=0.001..0.001 rows=1 loops=1)

              Index Cond: (num = 97)

              Buffers: shared hit=2

Planning:

  Buffers: shared hit=3

Planning Time: 2.740 ms

Execution Time: 1.116 ms

EXPLAIN