On Dec 20, 2011, at 7:21 PM, Paul Ramsey wrote: > Chop up the continents into smaller pieces. >
hmmm... I am not sure I understand the above. And then what? UNION each smaller piece query? > 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
