[postgis-users] time consuming intersection query

[Nelson Guda]

Hi all,

I'm trying to do an intersection query to find which elements of one  
database (county shapes) intersects with another database of  
thousands of shapes.  The query seems to get stuck running, and I'm  
not sure why.  Here is the language I used:

create table iracounties as select c.name, c.state_name, c.id from  
counties as c, iraname as i where intersects(c.the_geom,i.wkb_geometry)

Am I doing something wrong, or is there some way to make this more  
efficient?

thanks,
nelson