Chop up the continents into smaller pieces.
On Tue, Dec 20, 2011 at 4:35 PM, Puneet Kishor <punk.k...@gmail.com> wrote: > This is probably a really basic question... my ST_Within or ST_Intersects > selecting points in a continent are way too slow (both take upward of 200 > secs). > > SELECT Count(c_id) > FROM c, continents n > WHERE ST_Intersects(c.the_geom, n.the_geom) AND > n.continent = 'North America'; > > > Both tables have gist indexes on the geometries. The above query has the > following plan > > "Aggregate (cost=9.66..9.67 rows=1 width=4)" > " -> Nested Loop (cost=0.00..9.66 rows=1 width=4)" > " Join Filter: _st_intersects(c.the_geom, n.the_geom)" > " -> Seq Scan on continents n (cost=0.00..1.10 rows=1 width=32)" > " Filter: ((continent)::text = 'North America'::text)" > " -> Index Scan using pbdb__collections_the_geom on collections c > (cost=0.00..8.30 rows=1 width=104)" > " Index Cond: (c.the_geom && n.the_geom)" > > The table c has approx 120K rows, and the continents table has 8 > rows.Suggestions on how I can improve this? Yes, the computer is otherwise > very swift and modern. > > > > -- > Puneet Kishor > _______________________________________________ > postgis-users mailing list > postgis-users@postgis.refractions.net > http://postgis.refractions.net/mailman/listinfo/postgis-users _______________________________________________ postgis-users mailing list postgis-users@postgis.refractions.net http://postgis.refractions.net/mailman/listinfo/postgis-users
