I have a global dataset of ecoregion boundaires. There are ~809 unique polygons in this dataset. I've imported it into PostGIS with SRS of 4326 and built a spatial index using the function below
CREATE INDEX ecoregionsindex ON ecoregions USING gist(geom);
Querying with a point takes ~150ms to run
SELECT id FROM "ecoregions" WHERE ST_Within (ST_PointFromText('POINT(-111 45)', 4326), geom);
Buffering ~20,000m around this point using the ST_DWithin() method takes about 15,000ms to run.
SELECT id FROM "ecoregions" WHERE ST_DWithin(ecoregions.geom, ST_MakePoint(-111,45)::geography, 20000);
Is there a way to optimize my data or the query above to run more quickly?