explain.depesz.com

PostgreSQL's explain analyze made readable

Result: pQfSt : OSM County Reduced - Count Trees

Settings
# exclusive inclusive rows x rows loops node
1. 10,936.418 16,797.363 ↑ 1.7 36 1

HashAggregate (cost=14,022.75..14,023.36 rows=61 width=6,536) (actual time=16,797.356..16,797.363 rows=36 loops=1)

  • Group Key: c.osm_id, c.name, c.way
  • Buffers: shared hit=144119
2. 39.916 5,860.945 ↓ 49.1 258,906 1

Nested Loop (cost=10.01..13,970.07 rows=5,268 width=6,536) (actual time=0.518..5,860.945 rows=258,906 loops=1)

  • Buffers: shared hit=37809
3. 0.043 0.043 ↑ 1.0 61 1

Seq Scan on county_polygon c (cost=0.00..18.61 rows=61 width=6,528) (actual time=0.015..0.043 rows=61 loops=1)

  • Buffers: shared hit=18
4. 5,783.288 5,820.986 ↓ 49.3 4,244 61

Bitmap Heap Scan on natural_point n (cost=10.01..227.85 rows=86 width=40) (actual time=6.328..95.426 rows=4,244 loops=61)

  • Recheck Cond: (c.way ~ way)
  • Filter: (("natural" = 'tree'::text) AND _st_contains(c.way, way))
  • Rows Removed by Filter: 4508
  • Heap Blocks: exact=5461
  • Buffers: shared hit=37791
5. 37.698 37.698 ↓ 33.3 8,752 61

Bitmap Index Scan on gix_osm_natural_point (cost=0.00..9.99 rows=263 width=0) (actual time=0.618..0.618 rows=8,752 loops=61)

  • Index Cond: (c.way ~ way)
  • Buffers: shared hit=3971