explain.depesz.com

PostgreSQL's explain analyze made readable

Result: HRZC : OSM Jefferson County Full - Tree Count Spill to Disk

Settings
# exclusive inclusive rows x rows loops node
1. 1,446.367 10,416.153 ↑ 1.0 1 1

GroupAggregate (cost=968.13..969.22 rows=1 width=6,085) (actual time=10,416.152..10,416.153 rows=1 loops=1)

  • Group Key: c.osm_id, c.name, c.way
  • Buffers: shared hit=1189, temp read=74553 written=74627
2. 7,693.516 8,969.786 ↓ 427.4 36,757 1

Sort (cost=968.13..968.35 rows=86 width=6,085) (actual time=6,098.885..8,969.786 rows=36,757 loops=1)

  • Sort Key: c.osm_id, c.way
  • Sort Method: external merge Disk: 280344kB
  • Buffers: shared hit=1189, temp read=74553 written=74627
3. 5.078 1,276.270 ↓ 427.4 36,757 1

Nested Loop (cost=10.28..965.37 rows=86 width=6,085) (actual time=8.478..1,276.270 rows=36,757 loops=1)

  • Buffers: shared hit=1189
4. 0.276 0.276 ↑ 1.0 1 1

Seq Scan on boundary_polygon c (cost=0.00..123.29 rows=1 width=6,077) (actual time=0.240..0.276 rows=1 loops=1)

  • Filter: ((name = 'Jefferson County'::text) AND (admin_level = '6'::text))
  • Rows Removed by Filter: 485
  • Buffers: shared hit=116
5. 1,262.972 1,270.916 ↓ 427.4 36,757 1

Bitmap Heap Scan on natural_point n (cost=10.28..841.22 rows=86 width=40) (actual time=8.231..1,270.916 rows=36,757 loops=1)

  • Recheck Cond: (c.way ~ way)
  • Filter: (("natural" = 'tree'::text) AND _st_contains(c.way, way))
  • Rows Removed by Filter: 23405
  • Heap Blocks: exact=628
  • Buffers: shared hit=1073
6. 7.944 7.944 ↓ 228.8 60,162 1

Bitmap Index Scan on gix_osm_natural_point (cost=0.00..10.26 rows=263 width=0) (actual time=7.944..7.944 rows=60,162 loops=1)

  • Index Cond: (c.way ~ way)
  • Buffers: shared hit=445