<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>Question out ignorance because I was not aware that this capability existed. </div><div><br></div><div>I might have a geometry for a country and separate geometries for the next layer of administrative regions (e.g. states in the United States). But there are often minor differences in the polygons such that the polygon for the country is nearly but not exactly the union of the states. How is this handled?</div><div><br></div><div>Thanks.</div><div><br></div><div>-=- Jerry</div><div><br></div><br><div><div>On Apr 11, 2012, at 11:42 AM, Michal Kubenka wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">Thank you.<br><br><div class="gmail_quote">On Wed, Apr 11, 2012 at 2:29 PM, Sandro Santilli <span dir="ltr"><<a href="mailto:strk@keybit.net">strk@keybit.net</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div class="im">On Mon, Apr 09, 2012 at 11:59:14PM +0200, Michal Kubenka wrote:<br>
> Actually what we need is some hierarchical base for relationship between<br>
> countries, cities, regions, etc.<br>
<br>
</div>PostGIS topology supports hirearchical modeling of layers, with each object<br>
in upper layer defined by items of the lower layer, down to primitives.<br>
<br>
--strk;<br>
<br>
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