explain.depesz.com

PostgreSQL's explain analyze made readable

Result: cBsU

Settings
# exclusive inclusive rows x rows loops node
1. 0.020 95.791 ↑ 1.0 25 1

Limit (cost=11,693.28..11,693.34 rows=25 width=576) (actual time=95.787..95.791 rows=25 loops=1)

2. 0.015 95.771 ↑ 1.3 25 1

Sort (cost=11,693.28..11,693.36 rows=33 width=576) (actual time=95.769..95.771 rows=25 loops=1)

  • Sort Key: (max(cm.created))
  • Sort Method: quicksort Memory: 31kB
3. 0.073 95.756 ↑ 1.0 33 1

WindowAgg (cost=8,129.30..11,692.44 rows=33 width=576) (actual time=95.742..95.756 rows=33 loops=1)

4. 0.080 95.683 ↑ 1.0 33 1

Nested Loop Left Join (cost=8,129.30..11,692.03 rows=33 width=560) (actual time=18.409..95.683 rows=33 loops=1)

5. 0.058 0.068 ↑ 1.0 33 1

Bitmap Heap Scan on direct_chat_group (cost=8.82..36.69 rows=33 width=24) (actual time=0.013..0.068 rows=33 loops=1)

  • Recheck Cond: ((account_id_one = 12) OR (account_id_two = 12))
  • Heap Blocks: exact=13
6. 0.001 0.010 ↓ 0.0 0 1

BitmapOr (cost=8.82..8.82 rows=33 width=0) (actual time=0.009..0.010 rows=0 loops=1)

7. 0.007 0.007 ↑ 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=0.007..0.007 rows=18 loops=1)

  • Index Cond: (account_id_one = 12)
8. 0.002 0.002 ↑ 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=0.002..0.002 rows=15 loops=1)

  • Index Cond: (account_id_two = 12)
9. 24.519 95.535 ↓ 0.0 0 33

Hash Join (cost=8,120.48..8,227.59 rows=1 width=536) (actual time=2.650..2.895 rows=0 loops=33)

  • Hash Cond: (cm.chat_group_id = chat_group.id)
10. 58.565 70.785 ↓ 1.9 9,015 33

HashAggregate (cost=8,112.53..8,159.87 rows=4,734 width=20) (actual time=0.485..2.145 rows=9,015 loops=33)

  • Group Key: cm.chat_group_id
11. 3.572 12.220 ↓ 2.1 9,985 1

Hash Left Join (cost=177.23..8,077.02 rows=4,734 width=12) (actual time=1.712..12.220 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. 7.911 8.627 ↓ 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=1.682..8.627 rows=9,985 loops=1)

  • Recheck Cond: (sender_id = 12)
  • Heap Blocks: exact=5,423
13. 0.716 0.716 ↓ 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=0.716..0.716 rows=9,985 loops=1)

  • Index Cond: (sender_id = 12)
14. 0.004 0.021 ↑ 1.0 1 1

Hash (cost=3.42..3.42 rows=1 width=12) (actual time=0.020..0.021 rows=1 loops=1)

  • Buckets: 1,024 Batches: 1 Memory Usage: 9kB
15. 0.001 0.017 ↑ 1.0 1 1

Subquery Scan on cgr (cost=0.41..3.42 rows=1 width=12) (actual time=0.017..0.017 rows=1 loops=1)

16. 0.001 0.016 ↑ 1.0 1 1

Limit (cost=0.41..3.41 rows=1 width=12) (actual time=0.016..0.016 rows=1 loops=1)

17. 0.015 0.015 ↑ 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=0.015..0.015 rows=1 loops=1)

  • Index Cond: (account_id = 12)
18. 0.066 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
19. 0.165 0.165 ↑ 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..0.005 rows=1 loops=33)

  • Index Cond: (id = direct_chat_group.chat_group_id)
Planning time : 0.358 ms
Execution time : 95.889 ms