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<DIV dir=ltr align=left><SPAN class=462204412-04082008><FONT face=Arial
color=#0000ff size=2>That is a little odd. What are you using to view the
data. I know for example QuantumGIS leaves out some geometries
(particularly when they are large geometries) unless you change some
setting on it. I noticed this once when I loaded up a large Candadian
dataset and thinking - THATS CANADA. Then I changed some setting and all
looked fine.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=462204412-04082008><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=462204412-04082008><FONT face=Arial
color=#0000ff size=2>With ST_Collect you probably get more geometries in
your MULTIPOLYGON than ST_Union since it won't dissolve the
boundaries, but you shouldn't be getting any geometries left
out.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=462204412-04082008><FONT face=Arial
color=#0000ff size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=462204412-04082008><FONT face=Arial
color=#0000ff size=2>Hope that helps,</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=462204412-04082008><FONT face=Arial
color=#0000ff size=2>Regina</FONT></SPAN></DIV><BR>
<DIV class=OutlookMessageHeader lang=en-us dir=ltr align=left>
<HR tabIndex=-1>
<FONT face=Tahoma size=2><B>From:</B>
postgis-users-bounces@postgis.refractions.net
[mailto:postgis-users-bounces@postgis.refractions.net] <B>On Behalf Of
</B>danny<BR><B>Sent:</B> Monday, August 04, 2008 8:24 AM<BR><B>To:</B> PostGIS
Users Discussion<BR><B>Subject:</B> Re: [postgis-users] Merge all polygons from
a dataset<BR></FONT><BR></DIV>
<DIV></DIV>
<DIV dir=ltr>Thanks Regina.<BR><BR>For some reason ST_Collect doesn't give
exactly the same result. For example I'm trying to merge european countries in
one shape and with ST_Collects it omits England and other islands while ST_Union
includes them. <BR>Anyway, my union finished after 4 hours.<BR>I'm joining two
tables on an ST_Intersect, one of which has ~15000 features (polygons) and the
other just one (a complex polygon). The query's been running for two hours... I
hope I'll see the end of it before the end of the day! (I've set the indexes
where I could and tuned PostgreSQL)<BR><BR>Regards. <BR><BR><BR><BR>
<DIV class=gmail_quote>On Mon, Aug 4, 2008 at 12:25 PM, Obe, Regina <SPAN
dir=ltr><<A
href="mailto:robe.dnd@cityofboston.gov">robe.dnd@cityofboston.gov</A>></SPAN>
wrote:<BR>
<BLOCKQUOTE class=gmail_quote
style="PADDING-LEFT: 1ex; MARGIN: 0pt 0pt 0pt 0.8ex; BORDER-LEFT: rgb(204,204,204) 1px solid">
<DIV>
<DIV dir=ltr align=left><SPAN><FONT face=Arial color=#0000ff size=2>Try the
trick documented here</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN><FONT face=Arial color=#0000ff size=2><A
href="http://postgis.refractions.net/documentation/manual-svn/ST_Collect.html"
target=_blank>http://postgis.refractions.net/documentation/manual-svn/ST_Collect.html</A></FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN><FONT face=Arial color=#0000ff size=2>On
hindsight - I realized the ST_Multi call here is probably unnecessary so you
can leave that part out.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN><FONT face=Arial color=#0000ff size=2>Hope that
helps,</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN><FONT face=Arial color=#0000ff
size=2>Regina</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN><FONT face=Arial color=#0000ff
size=2></FONT></SPAN> </DIV><BR>
<DIV lang=en-us dir=ltr align=left>
<HR>
<FONT face=Tahoma size=2>
<DIV class=Ih2E3d><B>From:</B> <A
href="mailto:postgis-users-bounces@postgis.refractions.net"
target=_blank>postgis-users-bounces@postgis.refractions.net</A> [mailto:<A
href="mailto:postgis-users-bounces@postgis.refractions.net"
target=_blank>postgis-users-bounces@postgis.refractions.net</A>] <B>On Behalf
Of </B>danny<BR></DIV><B>Sent:</B> Monday, August 04, 2008 5:04 AM
<DIV>
<DIV></DIV>
<DIV class=Wj3C7c><BR><B>To:</B> PostGIS Users Discussion<BR><B>Subject:</B>
Re: [postgis-users] Merge all polygons from a
dataset<BR></DIV></DIV></FONT><BR></DIV>
<DIV>
<DIV></DIV>
<DIV class=Wj3C7c>
<DIV></DIV>
<DIV dir=ltr>I'm getting very long processing time from ST_Union (on a shape
of europe at 1/100000 it's been running since 2 hours and hasn't finished yet;
on my previous one of 1/1000000 it took ~1 hour)<BR>Any other alternative and
quicker ways to accomplish the same operation?<BR>I just executed
st_buffer(st_collect(the_geom)) but still waiting. Should it take as long?
ST_Collect by itself executes fast but it's result violates the geometry check
constraint. <BR><BR><BR><BR>
<DIV class=gmail_quote>On Fri, Aug 1, 2008 at 5:31 PM, danny <SPAN
dir=ltr><<A href="mailto:whatevar89@gmail.com"
target=_blank>whatevar89@gmail.com</A>></SPAN> wrote:<BR>
<BLOCKQUOTE class=gmail_quote
style="PADDING-LEFT: 1ex; MARGIN: 0pt 0pt 0pt 0.8ex; BORDER-LEFT: rgb(204,204,204) 1px solid">
<DIV dir=ltr>Thanks Robert.<BR><BR>I actually exported from ogr2ogr and it
created a shape that worked fine in ArcView.<BR><BR>Best
<DIV>
<DIV></DIV>
<DIV><BR> <BR><BR><BR>
<DIV class=gmail_quote>On Fri, Aug 1, 2008 at 5:19 PM, Burgholzer,Robert
<SPAN dir=ltr><<A href="mailto:rwburgholzer@deq.virginia.gov"
target=_blank>rwburgholzer@deq.virginia.gov</A>></SPAN> wrote:<BR>
<BLOCKQUOTE class=gmail_quote
style="PADDING-LEFT: 1ex; MARGIN: 0pt 0pt 0pt 0.8ex; BORDER-LEFT: rgb(204,204,204) 1px solid">
<DIV lang=EN-US link="blue" vlink="blue">
<DIV>
<P><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">Could ArcView
perhaps want some columns other than just the shape? Perhaps you
could put a numeric ID or something else in there.</SPAN></FONT></P>
<P><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"></SPAN></FONT> </P>
<P><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">Just a
thought,</SPAN></FONT></P>
<P><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"></SPAN></FONT> </P>
<DIV>
<P><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">Robert W.
Burgholzer</SPAN></FONT></P>
<P><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">Surface Water
Modeler</SPAN></FONT></P>
<P><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">Office of Water
Supply and Planning</SPAN></FONT></P>
<P><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">Virginia
Department of Environmental Quality</SPAN></FONT></P>
<P><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"><A
href="mailto:rwburgholzer@deq.virginia.gov"
target=_blank>rwburgholzer@deq.virginia.gov</A></SPAN></FONT></P>
<P><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">804-698-4405</SPAN></FONT></P>
<P><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">Open Source
Modeling Tools:</SPAN></FONT></P>
<P><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"><A
href="http://sourceforge.net/projects/npsource/"
target=_blank>http://sourceforge.net/projects/npsource/</A></SPAN></FONT></P></DIV>
<P style="MARGIN-LEFT: 0.5in"><FONT face=Tahoma size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma">
<DIV>-----Original Message-----<BR><B><SPAN
style="FONT-WEIGHT: bold">From:</SPAN></B> <A
href="mailto:postgis-users-bounces@postgis.refractions.net"
target=_blank>postgis-users-bounces@postgis.refractions.net</A> [mailto:<A
href="mailto:postgis-users-bounces@postgis.refractions.net"
target=_blank>postgis-users-bounces@postgis.refractions.net</A>] <B><SPAN
style="FONT-WEIGHT: bold">On Behalf Of </SPAN></B>danny<BR></DIV>
<DIV>
<DIV></DIV>
<DIV><B><SPAN style="FONT-WEIGHT: bold">Sent:</SPAN></B> Friday, August
01, 2008 9:30 AM<BR><B><SPAN style="FONT-WEIGHT: bold">To:</SPAN></B>
PostGIS Users Discussion<BR><B><SPAN
style="FONT-WEIGHT: bold">Subject:</SPAN></B> Re: [postgis-users] Merge
all polygons from a dataset</DIV></DIV></SPAN></FONT>
<P></P>
<P></P>
<DIV>
<DIV></DIV>
<DIV>
<P style="MARGIN-LEFT: 0.5in"><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"></SPAN></FONT> </P>
<DIV>
<P
style="MARGIN-BOTTOM: 12pt; MARGIN-LEFT: 0.5in; MARGIN-RIGHT: 0in"><FONT
face="Times New Roman" size=3><SPAN style="FONT-SIZE: 12pt">Many thanks,
Regina! Indeed ST_Union generated the polygon, invisible in PgAdmin!!
<BR><BR>It creates a nice layer when I open it in uDig. <BR><BR>However
when I export it with pgsql2shp, the shape is unreadable by ArcView with
the errmsg: Number of shapes does not match the number of table
records.<BR><BR>Here's how I created the layer:<BR><BR>create table
europe_contour();<BR>SELECT addgeometrycolumn('db, 'europe_contour',
'the_geom', 32767,'MULTIPOLYGON', 2 );<BR>insert into
europe_contour(the_geom) values( (select st_union(the_geom) from
europe));<BR><BR>Then I generate the shapefile: <BR><BR>"c:\Program
Files\PostgreSQL\8.3\bin\pgsql2shp.exe" -u postgres -P password -f
europe_contour db europe_contour<BR><BR>Any suggestions perhaps on
anything I've wrong?<BR><BR></SPAN></FONT></P>
<DIV>
<P style="MARGIN-LEFT: 0.5in"><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt">On Fri, Aug 1, 2008 at 1:15 PM, Obe, Regina <<A
href="mailto:robe.dnd@cityofboston.gov"
target=_blank>robe.dnd@cityofboston.gov</A>> wrote:</SPAN></FONT></P>
<DIV>
<P style="MARGIN-LEFT: 0.5in"><FONT face=Arial color=blue size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Arial">Erik,</SPAN></FONT></P>
<P style="MARGIN-LEFT: 0.5in"><FONT face=Arial color=blue size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Arial">How were you
using ST_Union and what exactly do you mean by no result. no result
as it looks blank? If you are using something like PgAdmin III - it
will look blank because it exceeds the buffer supported by PgAdmin
III.</SPAN></FONT></P>
<P style="MARGIN-LEFT: 0.5in"><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"></SPAN></FONT> </P>
<P style="MARGIN-LEFT: 0.5in"><FONT face=Arial color=blue size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Arial">SELECT the_geom
is null </SPAN></FONT></P>
<P style="MARGIN-LEFT: 0.5in"><FONT face=Arial color=blue size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Arial">FROM (somequery
or table) as foo</SPAN></FONT></P>
<DIV>
<P style="MARGIN-LEFT: 0.5in"><FONT face=Arial color=blue size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Arial">LIMIT
1</SPAN></FONT></P></DIV>
<DIV>
<P style="MARGIN-LEFT: 0.5in"><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"></SPAN></FONT> </P></DIV>
<DIV>
<P style="MARGIN-LEFT: 0.5in"><FONT face=Arial color=blue size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Arial">will tell you if
its actually returning no geometry</SPAN></FONT></P></DIV>
<DIV>
<P style="MARGIN-LEFT: 0.5in"><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"></SPAN></FONT> </P></DIV>
<DIV>
<P style="MARGIN-LEFT: 0.5in"><FONT face=Arial color=blue size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Arial">Hope that
helps,</SPAN></FONT></P></DIV>
<DIV>
<P style="MARGIN-LEFT: 0.5in"><FONT face=Arial color=blue size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: blue; FONT-FAMILY: Arial">Regina</SPAN></FONT></P></DIV>
<P style="MARGIN-LEFT: 0.5in"><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt"></SPAN></FONT> </P>
<DIV style="MARGIN-LEFT: 0.5in; TEXT-ALIGN: center" align=center><FONT
face="Times New Roman" size=3><SPAN style="FONT-SIZE: 12pt">
<HR align=center width="100%" SIZE=2>
</SPAN></FONT></DIV>
<P
style="MARGIN-BOTTOM: 12pt; MARGIN-LEFT: 0.5in; MARGIN-RIGHT: 0in"><B><FONT
face=Tahoma size=2><SPAN
style="FONT-WEIGHT: bold; FONT-SIZE: 10pt; FONT-FAMILY: Tahoma">From:</SPAN></FONT></B><FONT
face=Tahoma size=2><SPAN style="FONT-SIZE: 10pt; FONT-FAMILY: Tahoma"> <A
href="mailto:postgis-users-bounces@postgis.refractions.net"
target=_blank>postgis-users-bounces@postgis.refractions.net</A> [mailto:<A
href="mailto:postgis-users-bounces@postgis.refractions.net"
target=_blank>postgis-users-bounces@postgis.refractions.net</A>] <B><SPAN
style="FONT-WEIGHT: bold">On Behalf Of </SPAN></B>danny<BR><B><SPAN
style="FONT-WEIGHT: bold">Sent:</SPAN></B> Friday, August 01, 2008 6:12
AM<BR><B><SPAN style="FONT-WEIGHT: bold">To:</SPAN></B> <A
href="mailto:postgis-users@postgis.refractions.net"
target=_blank>postgis-users@postgis.refractions.net</A><BR><B><SPAN
style="FONT-WEIGHT: bold">Subject:</SPAN></B> [postgis-users] Merge all
polygons from a dataset</SPAN></FONT></P>
<DIV>
<DIV>
<DIV>
<P style="MARGIN-LEFT: 0.5in"><FONT face="Times New Roman" size=3><SPAN
style="FONT-SIZE: 12pt">Hello everybody,<BR><BR>I've converted a shapefile
of Europe to PostGIS. I would like to merge all the countries together so
that I only have one polygon left, the whole contour of Europe. I have
tried ST_Union that gives me no result. I've tried several other functions
to no avail. Does anybody know how I should proceed?<BR><BR>Many
thanks,<BR><BR>Erik</SPAN></FONT></P></DIV></DIV></DIV></DIV>
<DIV>
<DIV style="MARGIN-LEFT: 0.5in; TEXT-ALIGN: center" align=center><FONT
face="Times New Roman" size=3><SPAN style="FONT-SIZE: 12pt">
<HR align=center width="100%" SIZE=1>
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