[postgis-users] Very slow intersection

[Brian Stempin]

Hi Ted,
Perhaps you should create the table of geometries and then update the table
instead:

create table countyShp as
select cty.gid, cty.the_geom as the_geom
from countyShpWideBound as cty;

UPDATE countyShp cty, uscoast cst
SET cty.the_geom = ST_Difference(cty.the_geom, cst.the_geom)
WHERE cty.the_geom && cst.the_geom
AND ST_Intersects(cty.the_geom, cst.the_geom);

(queries untested, of course)

HTH,
Brian
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