Hi, I have a table with polygons and a table with shared boundaries. My goal is to detect the left and right polygons and attach joined left and righty polygon type to the LINESTRINGS of the shared boundaries. I want to later label these linestrings.
Here is my query: SELECT lin.gid, lin.the_geom, lin._tid, array_to_string(array_textsort(array_distinct(array_agg(zonart.wert::text))),',') AS zonen FROM raumplanung.grundwasserschutz__grundwassers_zonen_geometrie lin LEFT JOIN raumplanung.grundwasserschutz__grundwassers_zonen__areas poly ON ST_Touches(lin.the_geom,poly.the_geom) AND ST_LENGTH(ST_SharedPaths(lin.the_geom,ST_ExteriorRing(poly.the_geom))) > 0 LEFT JOIN raumplanung._zonenart_gwszone zonart ON poly.art = zonart.code GROUP BY lin.gid, lin.the_geom, lin._tid; This query seems to work fine. The results are plausible. The only problem is the time it takes. For rather small datasets it already runs more than a minute. Do you have any idea how I could speed up my query? Thank you for your ideas. Andreas _______________________________________________ postgis-users mailing list [email protected] http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-users
