explain.depesz.com

PostgreSQL's explain analyze made readable

Result: iRkt

Settings
# exclusive inclusive rows x rows loops node
1. 0.077 3,416.708 ↑ 1.0 5 1

Nested Loop (cost=14.54..46.03 rows=5 width=498) (actual time=244.478..3,416.708 rows=5 loops=1)

2. 72.062 3,416.491 ↑ 1.0 5 1

Merge Join (cost=14.26..44.46 rows=5 width=510) (actual time=244.418..3,416.491 rows=5 loops=1)

  • Merge Cond: (lvl.subtestid = tst.subtestid)
  • Join Filter: ((x.studentidcode = stu.studentidcode) AND ((x.subtestcode)::text = (tst.subtestcode)::text))
  • Rows Removed by Join Filter: 382670
3. 1,743.413 3,327.270 ↑ 1.0 382,675 1

Nested Loop (cost=0.14..576,166.12 rows=382,675 width=530) (actual time=183.967..3,327.270 rows=382,675 loops=1)

  • Join Filter: ((x.levelcode)::text = (lvl.levelcode)::text)
  • Rows Removed by Join Filter: 11250645
4. 0.473 0.473 ↑ 1.0 152 1

Index Only Scan using udx_dim_assessmentlevel on dim_assessmentlevel lvl (cost=0.14..29.12 rows=152 width=14) (actual time=0.022..0.473 rows=152 loops=1)

  • Index Cond: (administrationid = 593218)
  • Heap Fetches: 152
5. 1,583.384 1,583.384 ↑ 1.0 76,535 152

Seq Scan on stg_document_event_session x (cost=0.00..2,833.69 rows=76,535 width=524) (actual time=0.055..10.417 rows=76,535 loops=152)

  • Filter: (administrationid = 593218)
6. 17.121 17.159 ↓ 382,685.0 382,685 1

Sort (cost=9.32..9.33 rows=1 width=44) (actual time=0.077..17.159 rows=382,685 loops=1)

  • Sort Key: tst.subtestid
  • Sort Method: quicksort Memory: 26kB
7. 0.005 0.038 ↓ 17.0 17 1

Nested Loop (cost=0.29..9.31 rows=1 width=44) (actual time=0.032..0.038 rows=17 loops=1)

8. 0.023 0.023 ↑ 1.0 1 1

Index Scan using pk_dim_participant on dim_participant stu (cost=0.29..8.30 rows=1 width=20) (actual time=0.022..0.023 rows=1 loops=1)

  • Index Cond: (participantid = 13)
  • Filter: (administrationid = 593218)
9. 0.010 0.010 ↓ 17.0 17 1

Seq Scan on dim_subtest tst (cost=0.00..1.00 rows=1 width=24) (actual time=0.008..0.010 rows=17 loops=1)

  • Filter: (administrationid = 593218)
10. 0.140 0.140 ↑ 1.0 1 5

Index Scan using udx_dim_assessmentsession on dim_assessmentsession ses (cost=0.28..0.31 rows=1 width=52) (actual time=0.028..0.028 rows=1 loops=5)

  • Index Cond: ((administrationid = 593218) AND ((testsessionidcode)::text = (x.testsessionidcode)::text))