explain.depesz.com

PostgreSQL's explain analyze made readable

Result: sWXt

Settings
# exclusive inclusive rows x rows loops node
1. 0.146 104.662 ↓ 5.3 79 1

GroupAggregate (cost=4,028.14..4,028.48 rows=15 width=66) (actual time=104.511..104.662 rows=79 loops=1)

  • Group Key: t.attribute_id, t.stamp
2. 0.080 104.516 ↓ 7.8 117 1

Sort (cost=4,028.14..4,028.18 rows=15 width=46) (actual time=104.491..104.516 rows=117 loops=1)

  • Sort Key: t.attribute_id, t.stamp
  • Sort Method: quicksort Memory: 34kB
3. 0.098 104.436 ↓ 7.8 117 1

Nested Loop Left Join (cost=3,566.80..4,027.85 rows=15 width=46) (actual time=103.776..104.436 rows=117 loops=1)

4. 0.065 104.180 ↓ 7.2 79 1

Nested Loop (cost=3,566.38..4,021.28 rows=11 width=34) (actual time=103.762..104.180 rows=79 loops=1)

5. 0.022 103.878 ↓ 1.5 79 1

Finalize GroupAggregate (cost=3,565.96..3,572.98 rows=54 width=12) (actual time=103.735..103.878 rows=79 loops=1)

  • Group Key: telemetry.attribute_id
6. 5.100 103.856 ↓ 2.6 142 1

Gather Merge (cost=3,565.96..3,572.17 rows=54 width=12) (actual time=103.729..103.856 rows=142 loops=1)

  • Workers Planned: 1
  • Workers Launched: 1
7. 0.059 98.756 ↓ 1.3 71 2 / 2

Sort (cost=2,565.95..2,566.08 rows=54 width=12) (actual time=98.740..98.756 rows=71 loops=2)

  • Sort Key: telemetry.attribute_id
  • Sort Method: quicksort Memory: 28kB
  • Worker 0: Sort Method: quicksort Memory: 28kB
8. 53.343 98.697 ↓ 1.3 71 2 / 2

Partial HashAggregate (cost=2,563.86..2,564.40 rows=54 width=12) (actual time=98.676..98.697 rows=71 loops=2)

  • Group Key: telemetry.attribute_id
9. 45.354 45.354 ↑ 1.2 85,955 2 / 2

Parallel Seq Scan on telemetry (cost=0.00..2,058.24 rows=101,124 width=12) (actual time=0.008..45.354 rows=85,955 loops=2)

10. 0.237 0.237 ↑ 1.0 1 79

Index Scan using telemetry_pkey1 on telemetry t (cost=0.42..8.29 rows=1 width=34) (actual time=0.003..0.003 rows=1 loops=79)

  • Index Cond: ((attribute_id = telemetry.attribute_id) AND (stamp = (max(telemetry.stamp))))
11. 0.158 0.158 ↑ 3.0 1 79

Index Scan using telemetry_list_pkey on telemetry_list tl (cost=0.42..0.57 rows=3 width=24) (actual time=0.002..0.002 rows=1 loops=79)

  • Index Cond: ((attribute_id = t.attribute_id) AND (stamp = t.stamp))
Planning time : 0.376 ms
Execution time : 104.813 ms