HashAggregate.4.sql

HashAggregate.4.sql

postgres=# 
EXPLAIN WITH subscribers AS (SELECT user_id FROM playlist_subscriptions WHERE list_id = 3343594)
SELECT * FROM devices WHERE user_id IN (SELECT user_id FROM subscribers);
                                                         QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------
 Hash Join  (cost=32995.28..241867.55 rows=294585 width=170)
   Hash Cond: (devices.user_id = playlist_subscriptions.user_id)
   ->  Seq Scan on devices  (cost=0.00..194390.62 rows=5516762 width=170)
   ->  Hash  (cost=32705.43..32705.43 rows=23188 width=8)
         ->  Bitmap Heap Scan on playlist_subscriptions  (cost=1350.13..32705.43 rows=23188 width=8)
               Recheck Cond: (list_id = 3343594)
               ->  Bitmap Index Scan on playlist_subscriptions_list_id_user_id_uniq  (cost=0.00..1344.34 rows=23188 width=0)
                     Index Cond: (list_id = 3343594)
(8 rows)