Slide 13
Slide 13 text
参考までに、PostgreSQL 11 の場合は、こう
13
subquery_test=> EXPLAIN SELECT * FROM (SELECT i, j, MIN(k) AS min, SUM(SUM(k)) OVER (PARTITION BY j) AS sum FROM
testschema.t1 GROUP BY i, j) AS dt WHERE j > 10 AND min < 3;
QUERY PLAN
--------------------------------------------------------------------------------------------------------------
Subquery Scan on dt (cost=61813.16..63733.16 rows=21333 width=44)
Filter: (dt.min < 3)
-> WindowAgg (cost=61813.16..62933.16 rows=64000 width=44)
-> Sort (cost=61813.16..61973.16 rows=64000 width=20)
Sort Key: t1.j
-> Finalize GroupAggregate (cost=36070.71..56704.11 rows=64000 width=20)
Group Key: t1.i, t1.j
-> Gather Merge (cost=36070.71..54784.11 rows=128000 width=20)
Workers Planned: 2
-> Partial GroupAggregate (cost=35070.68..39009.71 rows=64000 width=20)
Group Key: t1.i, t1.j
-> Sort (cost=35070.68..35730.49 rows=263922 width=12)
Sort Key: t1.i, t1.j
-> Parallel Seq Scan on t1 (cost=0.00..6793.33 rows=263922 width=12)
Filter: (j > 10)
(15 rows)
少し表現は違うものの
MySQL 8.0 と同様に