'[postgis-users] Noob request - using ST_SimplifyPreserveTopology()'

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List:       postgis-users
Subject:    [postgis-users] Noob request - using ST_SimplifyPreserveTopology()
From:       Christian Guirreri <christian () guirreri ! com>
Date:       2011-06-27 17:37:09
Message-ID: BANLkTinzQ6LydpipXiXmFYTmWwOfGKvmuw () mail ! gmail ! com
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I'm trying to do something fairly simple. I'd like to take the Tiger 2010
Data - tl_2010_us_cd111 and tl_2010_us_county10 - and create shape files
that are considerably smaller and more simplified. In the past I've just
used MapShaper and been OK with that, but I was having trouble
uploading tl_2010_us_county10 into it and I've decided its time to learn
some GIS basics anyway.

I've definitely successfully setup my environment - PostegreSQL 9 with
PostGIS. I've used the shp2pgsql wizard included with pgadmin to import the
data sets into their own databases, without the "Load Geography column"
checked. I've been able to export this data back to shp using pgsql2shp and
view the resulting shp in QuantumGIS and ACDSee Canvas.

But when it comes to simplification - I'm not sure where to even start. I'm
no database expert beyond some simple mysql so GIS is especially
overwhelming. I only know that I want to use ST_SimplifyPreserveTopology()
as I'm fairly certain a number of things will disappear if I don't.

Would love if someone could provide me with the SQL to make this happen!

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I&#39;m trying to do something fairly simple. I&#39;d like to take the Tiger 2010 \
Data - tl_2010_us_cd111 and tl_2010_us_county10 - and create shape files that are \
considerably smaller and more simplified. In the past I&#39;ve just used MapShaper \
and been OK with that, but I was having trouble uploading tl_2010_us_county10 into it \
and I&#39;ve decided its time to learn some GIS basics anyway.<div> \
<br></div><div><span class="Apple-style-span">I&#39;ve definitely successfully setup \
my environment - PostegreSQL 9 with PostGIS. I&#39;ve used the </span>shp2pgsql \
wizard included with pgadmin to import the data sets into their own databases, \
without the &quot;Load Geography column&quot; checked. I&#39;ve been able to export \
this data back to shp using pgsql2shp and view the resulting shp in QuantumGIS and \
ACDSee Canvas.</div> <div><br></div><div>But when it comes to simplification - \
I&#39;m not sure where to even start. I&#39;m no database expert beyond some simple \
mysql so GIS is especially overwhelming. I only know that I want to use \
ST_SimplifyPreserveTopology() as I&#39;m fairly certain a number of things will \
disappear if I don&#39;t.</div> <div><br></div><div>Would love if someone could \
provide me with the SQL to make this happen!</div>

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