explain.depesz.com

PostgreSQL's explain analyze made readable

Result: qu5h : According to Department of Education (2009), several studies have reported a number of short comings in the teaching and learning on Mathematics in South Africa. In 2001 a study was conducted by the Third International Mathematics and Science Study in which South Africa participated with 41 others, reports that South African Mathematics learners came last with a mean score of 351 this mean was significantly lower than the international benchmark of 513. The Third International Mathematics and Science Study conducted in 2009 revealed that Grade 8 learners once again performed poorly. Their mean score of 275 was significantly below the international mean of 487. The South African mean of 275 was lower than that of Morocco, Tunisia, and other developing countries such as Chile, Indonesia, Malaysia, and the Philippines.

Settings
# exclusive inclusive rows x rows loops node
1. 0.158 55.012 ↑ 11.4 71 1

Sort (cost=146.63..148.65 rows=808 width=138) (actual time=55.009..55.012 rows=71 loops=1)

  • Sort Key: n.nspname, p.proname, (pg_get_function_arguments(p.oid))
  • Sort Method: quicksort Memory: 43kB
2. 1.378 54.854 ↑ 11.4 71 1

Hash Join (cost=1.14..107.61 rows=808 width=138) (actual time=42.495..54.854 rows=71 loops=1)

  • Hash Cond: (p.pronamespace = n.oid)
3. 53.465 53.465 ↓ 3.0 2,402 1

Seq Scan on pg_proc p (cost=0.00..89.30 rows=808 width=78) (actual time=0.052..53.465 rows=2,402 loops=1)

  • Filter: pg_function_is_visible(oid)
4. 0.004 0.011 ↑ 1.0 4 1

Hash (cost=1.09..1.09 rows=4 width=68) (actual time=0.011..0.011 rows=4 loops=1)

  • Buckets: 1024 Batches: 1 Memory Usage: 1kB
5. 0.007 0.007 ↑ 1.0 4 1

Seq Scan on pg_namespace n (cost=0.00..1.09 rows=4 width=68) (actual time=0.005..0.007 rows=4 loops=1)

  • Filter: ((nspname <> 'pg_catalog'::name) AND (nspname <> 'information_schema'::name))