У меня есть запрос, который выполняет несколько соединений. Я пытаюсь получить только те позиции каждого ключевого слова, которые являются последними в результатах.postgres two column sort low performance
Вот запрос:
SELECT DISTINCT ON (p.keyword_id)
a.id AS account_id,
w.parent_id AS parent_id,
w.name AS name,
p.position AS position
FROM websites w
JOIN accounts a ON w.account_id = a.id
JOIN keywords k ON k.website_id = w.parent_id
JOIN positions p ON p.website_id = w.parent_id
WHERE a.amount > 0 AND w.parent_id NOTNULL AND (round((a.amount/a.payment_renewal_period), 2) BETWEEN 1 AND 19)
ORDER BY p.keyword_id, p.created_at DESC;
план с затратами на этот запрос выглядит следующим образом:
Unique (cost=73673.65..76630.38 rows=264 width=40) (actual time=30777.117..49143.023 rows=259 loops=1)
-> Sort (cost=73673.65..75152.02 rows=591347 width=40) (actual time=30777.116..47352.373 rows=10891486 loops=1)
Sort Key: p.keyword_id, p.created_at DESC
Sort Method: external merge Disk: 512672kB
-> Merge Join (cost=219.59..812.26 rows=591347 width=40) (actual time=3.487..3827.028 rows=10891486 loops=1)
Merge Cond: (w.parent_id = k.website_id)
-> Nested Loop (cost=128.46..597.73 rows=1268 width=44) (actual time=3.378..108.915 rows=61582 loops=1)
-> Nested Loop (cost=2.28..39.86 rows=1 width=28) (actual time=0.026..0.216 rows=7 loops=1)
-> Index Scan using index_websites_on_parent_id on websites w (cost=0.14..15.08 rows=4 width=28) (actual time=0.004..0.023 rows=7 loops=1)
Index Cond: (parent_id IS NOT NULL)
-> Bitmap Heap Scan on accounts a (cost=2.15..6.18 rows=1 width=4) (actual time=0.019..0.020 rows=1 loops=7)
Recheck Cond: (id = w.account_id)
Filter: ((amount > '0'::numeric) AND (round((amount/(payment_renewal_period)::numeric), 2) >= '1'::numeric) AND (round((amount/(payment_renewal_period)::numeric), 2) <= '19'::numeric))
Heap Blocks: exact=7
-> Bitmap Index Scan on accounts_pkey (cost=0.00..2.15 rows=1 width=0) (actual time=0.006..0.006 rows=1 loops=7)
Index Cond: (id = w.account_id)
-> Bitmap Heap Scan on positions p (cost=126.18..511.57 rows=4631 width=16) (actual time=0.994..8.226 rows=8797 loops=7)
Recheck Cond: (website_id = w.parent_id)
Heap Blocks: exact=1004
-> Bitmap Index Scan on index_positions_on_5_columns (cost=0.00..125.02 rows=4631 width=0) (actual time=0.965..0.965 rows=8797 loops=7)
Index Cond: (website_id = w.parent_id)
-> Sort (cost=18.26..18.92 rows=264 width=4) (actual time=0.106..1013.966 rows=10891487 loops=1)
Sort Key: k.website_id
Sort Method: quicksort Memory: 37kB
-> Seq Scan on keywords k (cost=0.00..7.64 rows=264 width=4) (actual time=0.005..0.039 rows=263 loops=1)
Planning time: 1.081 ms
Execution time: 49184.222 ms
Дело в том, когда я запускаю запрос с w.id
вместо w.parent_id
в присоединиться ПОЗИЦИИ часть общей сокращается до
Unique (cost=3621.07..3804.99 rows=264 width=40) (actual time=128.430..139.550 rows=259 loops=1)
-> Sort (cost=3621.07..3713.03 rows=36784 width=40) (actual time=128.429..135.444 rows=40385 loops=1)
Sort Key: p.keyword_id, p.created_at DESC
Sort Method: external sort Disk: 2000kB
-> Merge Join (cost=128.73..831.59 rows=36784 width=40) (actual time=25.521..63.299 rows=40385 loops=1)
Merge Cond: (k.website_id = w.id)
-> Index Only Scan using index_keywords_on_website_id_deleted_at on keywords k (cost=0.27..24.23 rows=264 width=4) (actual time=0.137..0.274 rows=263 loops=1)
Heap Fetches: 156
-> Materialize (cost=128.46..606.85 rows=1268 width=44) (actual time=3.772..49.587 rows=72242 loops=1)
-> Nested Loop (cost=128.46..603.68 rows=1268 width=44) (actual time=3.769..30.530 rows=61582 loops=1)
-> Nested Loop (cost=2.28..45.80 rows=1 width=32) (actual time=0.047..0.204 rows=7 loops=1)
-> Index Scan using websites_pkey on websites w (cost=0.14..21.03 rows=4 width=32) (actual time=0.007..0.026 rows=7 loops=1)
Filter: (parent_id IS NOT NULL)
Rows Removed by Filter: 4
-> Bitmap Heap Scan on accounts a (cost=2.15..6.18 rows=1 width=4) (actual time=0.018..0.019 rows=1 loops=7)
Recheck Cond: (id = w.account_id)
Filter: ((amount > '0'::numeric) AND (round((amount/(payment_renewal_period)::numeric), 2) >= '1'::numeric) AND (round((amount/(payment_renewal_period)::numeric), 2) <= '19'::numeric))
Heap Blocks: exact=7
-> Bitmap Index Scan on accounts_pkey (cost=0.00..2.15 rows=1 width=0) (actual time=0.004..0.004 rows=1 loops=7)
Index Cond: (id = w.account_id)
-> Bitmap Heap Scan on positions p (cost=126.18..511.57 rows=4631 width=16) (actual time=0.930..2.341 rows=8797 loops=7)
Recheck Cond: (website_id = w.parent_id)
Heap Blocks: exact=1004
-> Bitmap Index Scan on index_positions_on_5_columns (cost=0.00..125.02 rows=4631 width=0) (actual time=0.906..0.906 rows=8797 loops=7)
Index Cond: (website_id = w.parent_id)
Planning time: 1.124 ms
Execution time: 157.167 ms
Показатели на веб-сайте сайты
Indexes:
"websites_pkey" PRIMARY KEY, btree (id)
"index_websites_on_account_id" btree (account_id)
"index_websites_on_deleted_at" btree (deleted_at)
"index_websites_on_domain_id" btree (domain_id)
"index_websites_on_parent_id" btree (parent_id)
"index_websites_on_processed_at" btree (processed_at)
индексов на позиции
Indexes:
"positions_pkey" PRIMARY KEY, btree (id)
"index_positions_on_5_columns" UNIQUE, btree (website_id, keyword_id, created_at, engine_id, region_id)
"overlap_index" btree (keyword_id, created_at)
Пожалуйста, покажите нам план выполнения, сгенерированный с помощью 'explain (analysis)'. –
С атрибутом parent_id? Я попытаюсь, но не уверен, когда запрос закончится ... – Robs
@a_horse_with_no_name Я обновил вопрос. Кроме того, при условии 'объяснять анализ' информации, но я должен был сделать это на db с меньшим количеством данных. – Robs