explain.depesz.com

PostgreSQL's explain analyze made readable

Result: 09pb

Settings
# exclusive inclusive rows x rows loops node
1. 0.003 99.980 ↑ 1.0 25 1

Limit (cost=11,712.12..11,712.18 rows=25 width=576) (actual time=99.976..99.980 rows=25 loops=1)

2. 0.012 99.977 ↑ 1.3 25 1

Sort (cost=11,712.12..11,712.20 rows=33 width=576) (actual time=99.975..99.977 rows=25 loops=1)

  • Sort Key: (max(cm.created))
  • Sort Method: quicksort Memory: 31kB
3. 0.076 99.965 ↑ 1.0 33 1

WindowAgg (cost=8,120.48..11,711.28 rows=33 width=576) (actual time=99.953..99.965 rows=33 loops=1)

4. 0.092 99.889 ↑ 1.0 33 1

Nested Loop Left Join (cost=8,120.48..11,710.87 rows=33 width=560) (actual time=20.702..99.889 rows=33 loops=1)

5. 0.335 0.335 ↑ 1.0 33 1

Seq Scan on direct_chat_group (cost=0.00..55.53 rows=33 width=24) (actual time=0.014..0.335 rows=33 loops=1)

  • Filter: ((account_id_one = 12) OR (account_id_two = 12))
  • Rows Removed by Filter: 1,936
6. 24.651 99.462 ↓ 0.0 0 33

Hash Join (cost=8,120.48..8,227.59 rows=1 width=536) (actual time=2.749..3.014 rows=0 loops=33)

  • Hash Cond: (cm.chat_group_id = chat_group.id)
7. 61.185 74.580 ↓ 1.9 9,015 33

HashAggregate (cost=8,112.53..8,159.87 rows=4,734 width=20) (actual time=0.541..2.260 rows=9,015 loops=33)

  • Group Key: cm.chat_group_id
8. 3.861 13.395 ↓ 2.1 9,985 1

Hash Left Join (cost=177.23..8,077.02 rows=4,734 width=12) (actual time=1.491..13.395 rows=9,985 loops=1)

  • Hash Cond: (cm.chat_group_id = cgr.chat_group_id)
  • Filter: (COALESCE((cm.created > cgr.read_time), false) IS FALSE)
9. 8.757 9.519 ↓ 1.1 9,985 1

Bitmap Heap Scan on chat_message cm (cost=173.79..8,038.08 rows=9,467 width=12) (actual time=1.469..9.519 rows=9,985 loops=1)

  • Recheck Cond: (sender_id = 12)
  • Heap Blocks: exact=5,423
10. 0.762 0.762 ↓ 1.1 9,985 1

Bitmap Index Scan on chat_message_sender_id_idx (cost=0.00..171.43 rows=9,467 width=0) (actual time=0.762..0.762 rows=9,985 loops=1)

  • Index Cond: (sender_id = 12)
11. 0.002 0.015 ↑ 1.0 1 1

Hash (cost=3.42..3.42 rows=1 width=12) (actual time=0.015..0.015 rows=1 loops=1)

  • Buckets: 1,024 Batches: 1 Memory Usage: 9kB
12. 0.001 0.013 ↑ 1.0 1 1

Subquery Scan on cgr (cost=0.41..3.42 rows=1 width=12) (actual time=0.013..0.013 rows=1 loops=1)

13. 0.001 0.012 ↑ 1.0 1 1

Limit (cost=0.41..3.41 rows=1 width=12) (actual time=0.012..0.012 rows=1 loops=1)

14. 0.011 0.011 ↑ 478.0 1 1

Index Scan using chat_group_read_order_idx on chat_group_read (cost=0.41..1,432.69 rows=478 width=12) (actual time=0.011..0.011 rows=1 loops=1)

  • Index Cond: (account_id = 12)
15. 0.033 0.231 ↑ 1.0 1 33

Hash (cost=7.94..7.94 rows=1 width=516) (actual time=0.007..0.007 rows=1 loops=33)

  • Buckets: 1,024 Batches: 1 Memory Usage: 9kB
16. 0.198 0.198 ↑ 1.0 1 33

Index Scan using chat_group_pkey on chat_group (cost=0.29..7.94 rows=1 width=516) (actual time=0.005..0.006 rows=1 loops=33)

  • Index Cond: (id = direct_chat_group.chat_group_id)
Planning time : 0.392 ms
Execution time : 100.052 ms