Hi Andy, I wouldn't like to guarantee that we know the best methods but i have found ST_Intersection to be very effective and fast. By querying one table with a polygon from another, it's been a doddle to either view a tabular result in pgAdmin (and export etc) or (as a cadcorp software user) to set up a "VIEW" using the same query set up in pgAdmin which can then be worked with as a layer is SIS. Had no problem handling significant datasets.
Give me a shout if you'd like a chat. Andy Andrew Terry [email protected] centremapslive.com 01886 834809 Andrew Kemp-2 wrote: > > Hello, > > I am getting confused after reading previous posts as to whether I should > be looking for Difference, Symdifference or a straight forward > ST_Intersection. > > I am trying to cut the polygons in overlay POSTCODES with the polygons in > overlay CUTTER and keep all the attributes from POSTCODES in the resultant > output. Both overlays I have decomposed so there are no multi-polygon > items. > > Is there a simple way to achieve this? And which method should I be using? > > Many thanks for all your support > Andy > > **************************************************************************** > This email is confidential and may be privileged and should not be used, > read > or copied by anyone who is not the original intended recipient. If you > have > received this email in error please inform the sender and delete it from > your mailbox or any other storage mechanism. Unless specifically stated, > nothing in this email constitutes an offer by Cadcorp and Cadcorp does not > warrant that any information contained in this email is accurate. > Cadcorp cannot accept liability for any statements made which are clearly > the > sender's own and not expressly made on behalf of Cadcorp or one of its > agents. > Please rely on your own virus check. No responsibility is taken by Cadcorp > for any damage arising out of any bug or virus infection. > **************************************************************************** > > _______________________________________________ > postgis-users mailing list > [email protected] > http://postgis.refractions.net/mailman/listinfo/postgis-users > > -- View this message in context: http://old.nabble.com/Basic-cookie-cutting-of-polys-with-polys-tp31997104p32000126.html Sent from the PostGIS - User mailing list archive at Nabble.com. _______________________________________________ postgis-users mailing list [email protected] http://postgis.refractions.net/mailman/listinfo/postgis-users
