explain.depesz.com

PostgreSQL's explain analyze made readable

Result: dA7L

Settings
# exclusive inclusive rows x rows loops node
1. 0.097 1.004 ↑ 1.0 400 1

Merge Full Join (cost=1.16..127.30 rows=400 width=67) (actual time=0.049..1.004 rows=400 loops=1)

2. 0.865 0.865 ↑ 1.0 400 1

Seq Scan on student (cost=0.00..120.00 rows=400 width=27) (actual time=0.020..0.865 rows=400 loops=1)

  • Filter: ((department)::text = 'CS1'::text)
  • Rows Removed by Filter: 5600
3. 0.018 0.042 ↑ 1.0 1 1

Materialize (cost=1.16..2.30 rows=1 width=40) (actual time=0.026..0.042 rows=1 loops=1)

4. 0.009 0.024 ↑ 1.0 1 1

Hash Join (cost=1.16..2.30 rows=1 width=40) (actual time=0.022..0.024 rows=1 loops=1)

  • Hash Cond: (t.section_id = s.section_id)
5. 0.007 0.007 ↑ 1.0 10 1

Seq Scan on takes t (cost=0.00..1.10 rows=10 width=12) (actual time=0.006..0.007 rows=10 loops=1)

6. 0.002 0.008 ↑ 1.0 1 1

Hash (cost=1.15..1.15 rows=1 width=28) (actual time=0.008..0.008 rows=1 loops=1)

  • Buckets: 1024 Batches: 1 Memory Usage: 9kB
7. 0.006 0.006 ↑ 1.0 1 1

Seq Scan on section s (cost=0.00..1.15 rows=1 width=28) (actual time=0.004..0.006 rows=1 loops=1)

  • Filter: ((semester = 1) AND (year = 2019))
  • Rows Removed by Filter: 9