explain.depesz.com

PostgreSQL's explain analyze made readable

Result: vK3

Settings
# exclusive inclusive rows x rows loops node
1. 0.512 6.088 ↑ 1.2 339 1

Sort (cost=624.86..625.88 rows=410 width=726) (actual time=6.039..6.088 rows=339 loops=1)

  • Sort Key: question_1.id
  • Sort Method: quicksort Memory: 409kB
  • Buffers: shared hit=363
2. 0.123 5.576 ↑ 1.2 339 1

Nested Loop (cost=228.6..607.06 rows=410 width=726) (actual time=1.074..5.576 rows=339 loops=1)

  • Buffers: shared hit=360
3. 0.003 0.033 ↑ 1.0 1 1

Nested Loop (cost=0..2.94 rows=1 width=99) (actual time=0.025..0.033 rows=1 loops=1)

  • Buffers: shared hit=2
4. 0.021 0.021 ↑ 1.0 1 1

Seq Scan on rel_users_exams rel_users_exams (cost=0..1.73 rows=1 width=27) (actual time=0.016..0.021 rows=1 loops=1)

  • Filter: ((rel_users_exams.exam_id = 1) AND ((rel_users_exams.user_username)::text = 'nicolas1'::text))
  • Buffers: shared hit=1
5. 0.009 0.009 ↑ 1.0 1 1

Seq Scan on exam exam_1 (cost=0..1.19 rows=1 width=72) (actual time=0.006..0.009 rows=1 loops=1)

  • Filter: (exam_1.id = 1)
  • Buffers: shared hit=1
6. 2.433 5.420 ↑ 1.2 339 1

Hash Join (cost=228.6..599 rows=410 width=627) (actual time=1.047..5.42 rows=339 loops=1)

  • Buffers: shared hit=358
7. 1.962 1.962 ↓ 1.0 14,726 1

Seq Scan on answer answer_1 (cost=0..311.13 rows=14,713 width=55) (actual time=0.007..1.962 rows=14,726 loops=1)

  • Buffers: shared hit=164
8. 0.041 1.025 ↑ 1.2 63 1

Hash (cost=227.66..227.66 rows=75 width=572) (actual time=1.025..1.025 rows=63 loops=1)

  • Buffers: shared hit=194
9. 0.984 0.984 ↑ 1.2 63 1

Seq Scan on question question_1 (cost=0..227.66 rows=75 width=572) (actual time=0.004..0.984 rows=63 loops=1)

  • Filter: (question_1.exam_id = 1)
  • Buffers: shared hit=194
Planning time : 1.206 ms
Execution time : 6.248 ms