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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>Yes, and AFAIK, you need to create an empty
shapefile ahead of time to output the result to, otherwise ArcMap will add a
new row/feature to the existing layer, which most likely is not what anyone
would want. Note the layer st99_d00_union in my screenshots. It is not
intuitive at all, I know. I would simply use one of the stand-alone tools if I
knew of one that performs the operation I want. I tried the Dissolve tool, like
you suggested, (specifying no attributes) and it appeared to perform an aggregate
union in 3.0 seconds. ArcMap might be faster because it does everything
in-memory (i.e. it does no file I/O).<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'>
postgis-users-bounces@postgis.refractions.net
[mailto:postgis-users-bounces@postgis.refractions.net] <b><span
style='font-weight:bold'>On Behalf Of </span></b>Dane Springmeyer<br>
<b><span style='font-weight:bold'>Sent:</span></b> Monday, August 18, 2008 3:22
PM<br>
<b><span style='font-weight:bold'>To:</span></b> <st1:PersonName w:st="on">PostGIS
Users Discussion</st1:PersonName><br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: [postgis-users]
PostGIS 1.3.3 on Windows XP Unstable</span></font><o:p></o:p></p>
</div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><st1:City w:st="on"><st1:place w:st="on"><font size=3
face="Times New Roman"><span style='font-size:12.0pt'>Regina</span></font></st1:place></st1:City>,<o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>To use the approach below you need to 'Stop Editing' so that the union
edits are written to the shapefile.<o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>However, I think an easier approach is to not use the GUI Editing
interface and rather the 'Dissolve' tool in the (</span></font><span
class=apple-style-span><font size=1 face=Verdana><span style='font-size:7.5pt;
font-family:Verdana'>Geoprocessing tool reference > Data Management toolbox
> Generalization toolset > Tools), which will take and input datasource
and output a new one through the 'ArcToolbox' dialog.</span></font></span><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><span class=apple-style-span><font size=1 face=Verdana><span
style='font-size:7.5pt;font-family:Verdana'>Here is the direct link to the tool
help (should help you find it in the Toolbox view):</span></font></span><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><a
href="http://webhelp.esri.com/arcgisdesktop/9.2/index.cfm?TopicName=Dissolve_(Data_Management)">http://webhelp.esri.com/arcgisdesktop/9.2/index.cfm?TopicName=Dissolve_(Data_Management)</a><o:p></o:p></span></font></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>A Happy-PosGIS-User-Once-A-Confused-Clicky-ArcGIS-User,<o:p></o:p></span></font></p>
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<div>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'>Dane<o:p></o:p></span></font></p>
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