Hello,
I have been having difficulty figuring out how I might go about doing a
difference of many lines and polygons. For context, I have many (>
3,000,000) contour lines that I want to difference based on many (>
180,000) lakes. My goal is to remove the sections of the lines that are
within the polygons. I know that I can use ST_Difference(aLine,
aPolygon) to do this for one feature, but, what would the syntax look
like to go though all my line and all my polygons and return just the
lines/parts of lines that are outside of the polygons (and do this in as
quickly and resource-friendly way as possible)? The machine I am
working on is a relatively well-powered desktop (quad core, 6GB RAM).
Thanks for any insight/suggestions,
Christy
--
Christy Nieman
GIS Technician
DM Solutions Group, Inc.
Email: [email protected]
Web: http://dmsolutions.ca
Web: http://research.dmsolutions.ca
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