explain.depesz.com

PostgreSQL's explain analyze made readable

Result: 85cD

Settings
# exclusive inclusive rows x rows loops node
1. 0.438 51.964 ↓ 1.2 4,028 1

Subquery Scan on vm (cost=27,851.02..28,261.45 rows=3,240 width=89) (actual time=51.006..51.964 rows=4,028 loops=1)

2. 0.000 51.526 ↓ 1.2 4,028 1

Limit (cost=27,851.02..28,229.05 rows=3,240 width=89) (actual time=51.004..51.526 rows=4,028 loops=1)

3. 57.590 65.522 ↓ 1.2 4,028 1

Gather Merge (cost=27,851.02..28,229.05 rows=3,240 width=89) (actual time=51.002..65.522 rows=4,028 loops=1)

  • Workers Planned: 2
  • Workers Launched: 2
4. 1.317 7.932 ↑ 1.2 1,343 3

Sort (cost=26,851.00..26,855.05 rows=1,620 width=89) (actual time=2.577..2.644 rows=1,343 loops=3)

  • Sort Key: m.start_time DESC
  • Sort Method: quicksort Memory: 716kB
  • Worker 0: Sort Method: quicksort Memory: 25kB
  • Worker 1: Sort Method: quicksort Memory: 25kB
5. 1.492 6.615 ↑ 1.2 1,343 3

Nested Loop (cost=84.73..26,764.64 rows=1,620 width=89) (actual time=0.249..2.205 rows=1,343 loops=3)

6. 0.610 1.095 ↑ 1.2 1,343 3

Parallel Bitmap Heap Scan on measurements (cost=84.30..13,603.12 rows=1,620 width=4) (actual time=0.241..0.365 rows=1,343 loops=3)

  • Recheck Cond: ((start_time > '2019-02-05 00:00:00'::timestamp without time zone) AND (start_time < '2019-02-06 00:00:00'::timestamp without time zone))
  • Heap Blocks: exact=69
7. 0.485 0.485 ↓ 1.0 4,028 1

Bitmap Index Scan on idx_measurements_start_time (cost=0.00..83.33 rows=3,889 width=0) (actual time=0.484..0.485 rows=4,028 loops=1)

  • Index Cond: ((start_time > '2019-02-05 00:00:00'::timestamp without time zone) AND (start_time < '2019-02-06 00:00:00'::timestamp without time zone))
8. 4.028 4.028 ↑ 1.0 1 4,028

Index Scan using pkey_measurements on measurements m (cost=0.44..8.12 rows=1 width=89) (actual time=0.001..0.001 rows=1 loops=4,028)

  • Index Cond: (measurement_id = measurements.measurement_id)