explain.depesz.com

PostgreSQL's explain analyze made readable

Result: oQCZ

Settings
# exclusive inclusive rows x rows loops node
1. 0.003 100.795 ↑ 1.0 25 1

Limit (cost=11,693.28..11,693.34 rows=25 width=576) (actual time=100.791..100.795 rows=25 loops=1)

2. 0.014 100.792 ↑ 1.3 25 1

Sort (cost=11,693.28..11,693.36 rows=33 width=576) (actual time=100.790..100.792 rows=25 loops=1)

  • Sort Key: (max(cm.created))
  • Sort Method: quicksort Memory: 31kB
3. 0.076 100.778 ↑ 1.0 33 1

WindowAgg (cost=8,129.30..11,692.44 rows=33 width=576) (actual time=100.766..100.778 rows=33 loops=1)

4. 0.100 100.702 ↑ 1.0 33 1

Nested Loop Left Join (cost=8,129.30..11,692.03 rows=33 width=560) (actual time=18.263..100.702 rows=33 loops=1)

5. 0.056 0.084 ↑ 1.0 33 1

Bitmap Heap Scan on direct_chat_group (cost=8.82..36.69 rows=33 width=24) (actual time=0.033..0.084 rows=33 loops=1)

  • Recheck Cond: ((account_id_one = 12) OR (account_id_two = 12))
  • Heap Blocks: exact=13
6. 0.001 0.028 ↓ 0.0 0 1

BitmapOr (cost=8.82..8.82 rows=33 width=0) (actual time=0.028..0.028 rows=0 loops=1)

7. 0.017 0.017 ↑ 1.0 18 1

Bitmap Index Scan on direct_chat_group_account_id_one_idx (cost=0.00..4.41 rows=18 width=0) (actual time=0.017..0.017 rows=18 loops=1)

  • Index Cond: (account_id_one = 12)
8. 0.010 0.010 ↑ 1.0 15 1

Bitmap Index Scan on direct_chat_group_account_id_two_idx (cost=0.00..4.39 rows=15 width=0) (actual time=0.010..0.010 rows=15 loops=1)

  • Index Cond: (account_id_two = 12)
9. 26.070 100.518 ↓ 0.0 0 33

Hash Join (cost=8,120.48..8,227.59 rows=1 width=536) (actual time=2.787..3.046 rows=0 loops=33)

  • Hash Cond: (cm.chat_group_id = chat_group.id)
10. 62.723 74.184 ↓ 1.9 9,015 33

HashAggregate (cost=8,112.53..8,159.87 rows=4,734 width=20) (actual time=0.457..2.248 rows=9,015 loops=33)

  • Group Key: cm.chat_group_id
11. 3.345 11.461 ↓ 2.1 9,985 1

Hash Left Join (cost=177.23..8,077.02 rows=4,734 width=12) (actual time=1.548..11.461 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)
12. 7.267 8.100 ↓ 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=1.525..8.100 rows=9,985 loops=1)

  • Recheck Cond: (sender_id = 12)
  • Heap Blocks: exact=5,423
13. 0.833 0.833 ↓ 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=0.833..0.833 rows=9,985 loops=1)

  • Index Cond: (sender_id = 12)
14. 0.003 0.016 ↑ 1.0 1 1

Hash (cost=3.42..3.42 rows=1 width=12) (actual time=0.016..0.016 rows=1 loops=1)

  • Buckets: 1,024 Batches: 1 Memory Usage: 9kB
15. 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)

16. 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)

17. 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)
18. 0.066 0.264 ↑ 1.0 1 33

Hash (cost=7.94..7.94 rows=1 width=516) (actual time=0.008..0.008 rows=1 loops=33)

  • Buckets: 1,024 Batches: 1 Memory Usage: 9kB
19. 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=0.006..0.006 rows=1 loops=33)

  • Index Cond: (id = direct_chat_group.chat_group_id)
Planning time : 0.571 ms
Execution time : 100.896 ms