Hi Alan. Also I'm not sure if the "service1 c, service1 d" and the "AND c.service_id<> d.service_id" parts are right. I'm not sure but sinse you don't uses this two tables in your query you can remove that parts of your query and it can be faster cause otherwise this two tables will be combined as cartesian product with the others and I don't think this is what you want. (I'm not pretty sure but I think this is what will happen if you do not remove that parts of your querys).
Rodrigo. On 7/10/07, Paul Ramsey <[EMAIL PROTECTED]> wrote:
Try this: CREATE table topology (stop_a, stop_b, distance) AS SELECT DISTINCT a.stop_reference, b.stop_reference, distance(a.east_north, b.east_north) FROM bus_stops1 a, bus_stops1 b, service1 c, service1 d WHERE distance(a.east_north, b.east_north) < 200 AND expand(a.east_north, 200) && b.east_north AND a.stop_reference <> b.stop_reference AND c.service_id <> d.service_id ORDER BY distance; -- Paul Ramsey Refractions Research http://www.refractions.net [EMAIL PROTECTED] Phone: 250-383-3022 Cell: 250-885-0632 _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
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