explain.depesz.com

PostgreSQL's explain analyze made readable

Result: SEpv : \dt *.*a* - Optimization for: base plan for \d from psql; plan #KrT2

options

Optimization path:

Optimization(s) for this plan:

# exclusive inclusive rows x rows loops node
1. 0.090 1.158 ↑ 1.0 44 1

Sort (cost=20.96..21.07 rows=45 width=224) (actual time=1.152..1.158 rows=44 loops=1)

  • Sort Key: n.nspname, c.relname
  • Sort Method: quicksort Memory: 37kB
2. 0.105 1.068 ↑ 1.0 44 1

Hash Join (cost=1.14..19.72 rows=45 width=224) (actual time=0.134..1.068 rows=44 loops=1)

  • Hash Cond: (c.relnamespace = n.oid)
3. 0.903 0.903 ↑ 1.2 44 1

Seq Scan on pg_class c (cost=0.00..16.97 rows=54 width=73) (actual time=0.022..0.903 rows=44 loops=1)

  • Filter: ((relname ~ '^(.*a.*)$'::text) AND (relkind = ANY ('{r,p,s,""}'::"char"[])))
  • Rows Removed by Filter: 298
4. 0.011 0.060 ↑ 1.2 4 1

Hash (cost=1.07..1.07 rows=5 width=68) (actual time=0.060..0.060 rows=4 loops=1)

  • Buckets: 1024 Batches: 1 Memory Usage: 9kB
5. 0.049 0.049 ↑ 1.2 4 1

Seq Scan on pg_namespace n (cost=0.00..1.07 rows=5 width=68) (actual time=0.029..0.049 rows=4 loops=1)

  • Filter: (nspname !~ '^pg_toast'::text)
  • Rows Removed by Filter: 2