Arnold,
Thanks very much, I think this is something that I can try out.
Seems like the resulting table could co-exist with the original,
and when I need tiled polygons, I can use the tiled version.
These data are expected to change only rarely, so that may suffice.
I do appreciate your willingness to spell it out for me in detail.
Sometimes it helps me to see these techniques as others might do them.
Peter
On 03/03/2011 07:03 PM, Arnold Helmut Engelmann wrote:
If you want to go the tiling route and want to try that: Create a layer of
tiles (boxes) at the size you want. Then run the following query:
CREATE TABLE
tiled_geo_units as
SELECT
ST_Intersection(a.geometry, b.geometry) AS geometry,
a.*,
b.*
FROM
geo_units as a,
tiles as b
WHERE
ST_Intersects(a.geometry, b.geometry)
Where "geo_units" is the table with your geological units, and "tiles" is the table of
boxes you created. This will intersect both layers and split the polygons at the tile boundaries. You can
also add to the WHERE clause if you want to filter out just the "large" polygons, otherwise this
will tile all your polygons. For this ST_NPoints will probably useful.
--
Peter N. Schweitzer (MS 954, U.S. Geological Survey, Reston, VA 20192)
(703) 648-6533 FAX: (703) 648-6252 email: pschweit...@usgs.gov
<http://geology.usgs.gov/peter/>
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