On 05/25/2012 07:26 PM, Sandro Santilli wrote:
On Fri, May 25, 2012 at 01:52:45PM +1000, Luca Morandini wrote:
after seeing some polygons disappear during the generalization
process, I found out that ST_Union and ST_Collect are different
beasts when dealing with intersecting lines.
Yes, ST_Collect simply puts things togheter. ST_Union computes the
point set union. Isn't the manual page clear about that ?
That is clear, what I did not suspect was the different behaviour when there are
"loops" in the collection of lines given as argument... well, it may be
ST_BuildArea that has a different behaviour when the argument is a collection of
linestrings or a single geometry.
Regards,
Luca Morandini
Data Architect - AURIN project
Department of Computing and Information Systems
University of Melbourne
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