#	exclusive	inclusive	rows x	rows	loops	node
1.	0.031	938.131	↑ 1.0	10	1	→ Limit (cost=12934.63..12934.66 rows=10 width=187) (actual time=938.092..938.131 rows=10 loops=1)
2.	39.025	938.100	↑ 62.0	10	1	→ Sort (cost=12934.63..12936.18 rows=620 width=187) (actual time=938.087..938.100 rows=10 loops=1) Sort Key: public.core_film.popularity Sort Method: top-N heapsort Memory: 19kB
3.	91.802	899.075	↓ 23.3	14450	1	→ Nested Loop (cost=9406.64..12921.23 rows=620 width=187) (actual time=597.901..899.075 rows=14450 loops=1)
4.	74.613	706.123	↓ 23.3	14450	1	→ Merge Left Join (cost=9406.64..9430.27 rows=620 width=165) (actual time=597.872..706.123 rows=14450 loops=1) Merge Cond: (public.core_film.parent_id = core_rating.parent_id) Filter: ((core_rating.last_displayed IS NULL) AND (((core_rating.type = 1) AND (core_rating.rating IS NULL)) OR (core_rating.user_id IS NULL)))
5.	69.255	598.155	↓ 9.7	16305	1	→ Sort (cost=2567.22..2571.43 rows=1684 width=82) (actual time=572.699..598.155 rows=16305 loops=1) Sort Key: public.core_film.parent_id Sort Method: quicksort Memory: 2520kB
6.	73.260	528.900	↓ 9.7	16305	1	→ Hash Join (cost=1994.63..2476.98 rows=1684 width=82) (actual time=429.260..528.900 rows=16305 loops=1) Hash Cond: (public.core_film.parent_id = "IN_subquery".parent_id)
7.	26.444	26.444	↑ 1.0	16634	1	→ Seq Scan on core_film (cost=0.00..382.34 rows=16634 width=78) (actual time=0.027..26.444 rows=16634 loops=1)
8.	28.517	429.196	↓ 9.7	16305	1	→ Hash (cost=1973.58..1973.58 rows=1684 width=4) (actual time=429.196..429.196 rows=16305 loops=1)
9.	49.747	400.679	↓ 9.7	16305	1	→ Subquery Scan "IN_subquery" (cost=1872.55..1973.58 rows=1684 width=4) (actual time=271.646..400.679 rows=16305 loops=1)
10.	53.685	350.932	↓ 9.7	16305	1	→ SetOp Except (cost=1872.55..1956.74 rows=1684 width=4) (actual time=271.642..350.932 rows=16305 loops=1)
11.	81.750	297.247	↓ 1.0	16963	1	→ Sort (cost=1872.55..1914.65 rows=16837 width=4) (actual time=271.631..297.247 rows=16963 loops=1) Sort Key: "SELECT 1".parent_id Sort Method: quicksort Memory: 1175kB
12.	62.940	215.497	↓ 1.0	16963	1	→ Append (cost=0.00..690.65 rows=16837 width=4) (actual time=0.020..215.497 rows=16963 loops=1)
13.	68.741	149.917	↑ 1.0	16634	1	→ Subquery Scan "SELECT 1" (cost=0.00..548.68 rows=16634 width=4) (actual time=0.016..149.917 rows=16634 loops=1)
14.	81.176	81.176	↑ 1.0	16634	1	→ Seq Scan on core_film (cost=0.00..382.34 rows=16634 width=4) (actual time=0.010..81.176 rows=16634 loops=1)
15.	1.352	2.640	↓ 1.6	329	1	→ Subquery Scan "SELECT 2" (cost=6.42..141.97 rows=203 width=4) (actual time=0.250..2.640 rows=329 loops=1)
16.	1.078	1.288	↓ 1.6	329	1	→ Bitmap Heap Scan on filmbasket_basketitem (cost=6.42..139.94 rows=203 width=4) (actual time=0.244..1.288 rows=329 loops=1) Recheck Cond: (user_id = 3) Filter: (wishlist IS NOT NULL)
17.	0.210	0.210	↓ 1.2	343	1	→ Bitmap Index Scan on filmbasket_basketitem_user_id (cost=0.00..6.37 rows=282 width=0) (actual time=0.210..0.210 rows=343 loops=1) Index Cond: (user_id = 3)
18.	19.715	33.355	↓ 2.2	5343	1	→ Sort (cost=6839.40..6845.48 rows=2431 width=83) (actual time=25.085..33.355 rows=5343 loops=1) Sort Key: core_rating.parent_id Sort Method: quicksort Memory: 672kB
19.	10.714	13.640	↓ 2.2	5343	1	→ Bitmap Heap Scan on core_rating (cost=43.27..6702.69 rows=2431 width=83) (actual time=3.344..13.640 rows=5343 loops=1) Recheck Cond: (user_id = 3)
20.	2.926	2.926	↓ 6.7	16240	1	→ Bitmap Index Scan on core_rating_user_id (cost=0.00..42.66 rows=2431 width=0) (actual time=2.926..2.926 rows=16240 loops=1) Index Cond: (user_id = 3)
21.	101.150	101.150	↑ 1.0	1	14450	→ Index Scan using core_object_pkey on core_object (cost=0.00..5.62 rows=1 width=26) (actual time=0.005..0.007 rows=1 loops=14450) Index Cond: (core_object.id = public.core_film.parent_id)

                                                                                                    QUERY PLAN                                                                                                    
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 Limit  (cost=12934.63..12934.66 rows=10 width=187) (actual time=938.092..938.131 rows=10 loops=1)
   ->  Sort  (cost=12934.63..12936.18 rows=620 width=187) (actual time=938.087..938.100 rows=10 loops=1)
         Sort Key: public.core_film.popularity
         Sort Method:  top-N heapsort  Memory: 19kB
         ->  Nested Loop  (cost=9406.64..12921.23 rows=620 width=187) (actual time=597.901..899.075 rows=14450 loops=1)
               ->  Merge Left Join  (cost=9406.64..9430.27 rows=620 width=165) (actual time=597.872..706.123 rows=14450 loops=1)
                     Merge Cond: (public.core_film.parent_id = core_rating.parent_id)
                     Filter: ((core_rating.last_displayed IS NULL) AND (((core_rating.type = 1) AND (core_rating.rating IS NULL)) OR (core_rating.user_id IS NULL)))
                     ->  Sort  (cost=2567.22..2571.43 rows=1684 width=82) (actual time=572.699..598.155 rows=16305 loops=1)
                           Sort Key: public.core_film.parent_id
                           Sort Method:  quicksort  Memory: 2520kB
                           ->  Hash Join  (cost=1994.63..2476.98 rows=1684 width=82) (actual time=429.260..528.900 rows=16305 loops=1)
                                 Hash Cond: (public.core_film.parent_id = "IN_subquery".parent_id)
                                 ->  Seq Scan on core_film  (cost=0.00..382.34 rows=16634 width=78) (actual time=0.027..26.444 rows=16634 loops=1)
                                 ->  Hash  (cost=1973.58..1973.58 rows=1684 width=4) (actual time=429.196..429.196 rows=16305 loops=1)                                      
                                       ->  Subquery Scan "IN_subquery"  (cost=1872.55..1973.58 rows=1684 width=4) (actual time=271.646..400.679 rows=16305 loops=1)
                                             ->  SetOp Except  (cost=1872.55..1956.74 rows=1684 width=4) (actual time=271.642..350.932 rows=16305 loops=1)
                                                   ->  Sort  (cost=1872.55..1914.65 rows=16837 width=4) (actual time=271.631..297.247 rows=16963 loops=1)
                                                         Sort Key: "*SELECT* 1".parent_id
                                                         Sort Method:  quicksort  Memory: 1175kB
                                                         ->  Append  (cost=0.00..690.65 rows=16837 width=4) (actual time=0.020..215.497 rows=16963 loops=1)
                                                               ->  Subquery Scan "*SELECT* 1"  (cost=0.00..548.68 rows=16634 width=4) (actual time=0.016..149.917 rows=16634 loops=1)
                                                                     ->  Seq Scan on core_film  (cost=0.00..382.34 rows=16634 width=4) (actual time=0.010..81.176 rows=16634 loops=1)
                                                               ->  Subquery Scan "*SELECT* 2"  (cost=6.42..141.97 rows=203 width=4) (actual time=0.250..2.640 rows=329 loops=1)
                                                                     ->  Bitmap Heap Scan on filmbasket_basketitem  (cost=6.42..139.94 rows=203 width=4) (actual time=0.244..1.288 rows=329 loops=1)
                                                                           Recheck Cond: (user_id = 3)
                                                                           Filter: (wishlist IS NOT NULL)
                                                                           ->  Bitmap Index Scan on filmbasket_basketitem_user_id  (cost=0.00..6.37 rows=282 width=0) (actual time=0.210..0.210 rows=343 loops=1)
                                                                                 Index Cond: (user_id = 3)
                     ->  Sort  (cost=6839.40..6845.48 rows=2431 width=83) (actual time=25.085..33.355 rows=5343 loops=1)
                           Sort Key: core_rating.parent_id
                           Sort Method:  quicksort  Memory: 672kB
                           ->  Bitmap Heap Scan on core_rating  (cost=43.27..6702.69 rows=2431 width=83) (actual time=3.344..13.640 rows=5343 loops=1)
                                 Recheck Cond: (user_id = 3)
                                 ->  Bitmap Index Scan on core_rating_user_id  (cost=0.00..42.66 rows=2431 width=0) (actual time=2.926..2.926 rows=16240 loops=1)
                                       Index Cond: (user_id = 3)
               ->  Index Scan using core_object_pkey on core_object  (cost=0.00..5.62 rows=1 width=26) (actual time=0.005..0.007 rows=1 loops=14450)
                     Index Cond: (core_object.id = public.core_film.parent_id)
 Total runtime: 938.864 ms
(39 rows)

Per node type stats

node type	count	sum of times	% of query
Append	1	62.940 ms	6.7 %
Bitmap Heap Scan	2	11.792 ms	1.3 %
Bitmap Index Scan	2	3.136 ms	0.3 %
Hash	1	28.517 ms	3.0 %
Hash Join	1	73.260 ms	7.8 %
Index Scan	1	101.150 ms	10.8 %
Limit	1	0.031 ms	0.0 %
Merge Left Join	1	74.613 ms	8.0 %
Nested Loop	1	91.802 ms	9.8 %
Seq Scan	2	107.620 ms	11.5 %
SetOp Except	1	53.685 ms	5.7 %
Sort	4	209.745 ms	22.4 %
Subquery Scan "SELECT 1"	1	68.741 ms	7.3 %
Subquery Scan "SELECT 2"	1	1.352 ms	0.1 %
Subquery Scan "IN_subquery"	1	49.747 ms	5.3 %

Per table stats

Table name	Scan count	Total time	% of query
scan type	count	sum of times	% of table
core_film	2	107.620 ms	11.5 %
Seq Scan	2	107.620 ms	100.0 %
core_object	1	101.150 ms	10.8 %
Index Scan	1	101.150 ms	100.0 %
core_rating	1	10.714 ms	1.1 %
Bitmap Heap Scan	1	10.714 ms	100.0 %
filmbasket_basketitem	1	1.078 ms	0.1 %
Bitmap Heap Scan	1	1.078 ms	100.0 %

explain.depesz.com

A tool for finding a real cause for slow queries.

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Per node type stats

Per table stats