[postgis-users] Optimizations: splitting large features

[Jeff Dege]

Which involves learning PGSQL.  Which I'll have to do, eventually.
 
It's not clear to me that this approach would work for polygons, but
it's not clear to me that I'm having this problem with anything but
linestrings, so that probably doesn't matter.  (I sometimes have to draw
maps showing hundreds of linear features criss-crossing over an area.
When I have hundreds of two-dimensional overlapping features, my maps
always seem to involve displaying just a few of them.)
 


________________________________

	From: postgis-users-bounces at postgis.refractions.net
[mailto:postgis-users-bounces at postgis.refractions.net] On Behalf Of
David William Bitner
	Sent: Friday, April 27, 2007 2:08 PM
	To: PostGIS Users Discussion
	Subject: Re: [postgis-users] Optimizations: splitting large
features
	
	
	Jeff--
	
	The linear referencing functions along with a bit of PL/PGSQL
can accomplish this pretty well with a basic loop to divide a segment
either by a distance or into a specific number of segments to split the
linear feature into. 
	
	David
	
	
	


		The other is to split features apart.  Instead, for
example, of having 
		one feature representing a river that snakes around over
a large area,
		and hence has to be included in nearly every spatial
query, break it
		apart into multiple features each of which represents a
short segment of 
		the river.
		
		

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.osgeo.org/pipermail/postgis-users/attachments/20070427/fed04887/attachment.html>