PostGIS Development Blog http://postgis.net/ 2014-07-25T03:37:34+00:00 PieCrust 0.8.7 Security releases 2.0.6 and 2.1.3 2014-05-19T00:00:00+00:00 2014-05-19T00:00:00+00:00 http://postgis.net/2014/05/19/postgis-2.0.6_and_2.1.3 Sandro Santilli Sandro Santillihttp://postgis.net <p>It has come to our attention that the PostGIS Raster support may give more privileges to users than an administrator is willing to grant. These include reading files from the filesystem and opening connections to network hosts.</p> Continue Reading by clicking title hyperlink .. PostGIS 2.0.5 Released 2014-03-31T00:00:00+00:00 2014-03-31T00:00:00+00:00 http://postgis.net/2014/03/31/postgis-2-0-5 Paul Ramsey Paul Ramseyhttp://postgis.net <p>The 2.0.5 release of PostGIS is <a href="http://download.osgeo.org/postgis/source/postgis-2.0.5.tar.gz">now available</a>.</p> <p>The PostGIS development team is happy to release patch for PostGIS 2.0, the 2.0.5 release. As befits a patch release, the focus is on bugs and breakages.</p> <p>Best served with a bottle of GEOS 3.3.9.</p> <p><a href="http://download.osgeo.org/postgis/source/postgis-2.0.5.tar.gz">http://download.osgeo.org/postgis/source/postgis-2.0.5.tar.gz</a></p> <p>Doc downloads: <a href="http://download.osgeo.org/postgis/docs/doc-html-2.0.5.tar.gz">html doc download</a> <a href="http://download.osgeo.org/postgis/docs/postgis-2.0.5.pdf">pdf doc download</a></p> Continue Reading by clicking title hyperlink .. PostGIS 2.1.2 Released 2014-03-31T00:00:00+00:00 2014-03-31T00:00:00+00:00 http://postgis.net/2014/03/31/postgis-2.1.2 Paul Ramsey Paul Ramseyhttp://postgis.net <p>The 2.1.2 release of PostGIS is <a href="http://download.osgeo.org/postgis/source/postgis-2.1.2.tar.gz">now available</a>.</p> <p>The PostGIS development team is happy to release patch for PostGIS 2.1, the 2.1.2 release. As befits a patch release, the focus is on bugs and breakages.</p> <p>Best served with a bottle of GEOS 3.4.2.</p> <p><a href="http://download.osgeo.org/postgis/source/postgis-2.1.2.tar.gz">http://download.osgeo.org/postgis/source/postgis-2.1.2.tar.gz</a></p> Continue Reading by clicking title hyperlink .. Getting intersections the faster way 2014-03-14T00:00:00+00:00 2014-03-14T00:00:00+00:00 http://postgis.net/2014/03/14/tip_intersection_faster Regina Obe Regina Obehttp://postgis.net <p>Doing an <a href="/docs/manual-dev/ST_Intersection.html" target="_blank"><code>ST_Intersection</code></a> is much slower than relation checks such as <a href="/docs/manual-dev/ST_Intersects.html" target="_blank"><code>ST_Intersects</code></a> , <a href="/docs/manual-dev/ST_CoveredBy.html" target="_blank"><code>ST_CoveredBy</code></a>, and , <a href="/docs/manual-dev/ST_Within.html" target="_blank"><code>ST_Within</code></a> . In many situations you know the intersection of 2 geometries without actually computing an intersection. In these cases, you can skip the costly <code>ST_Intersection</code> call. Cases like this:</p> <ol> <li>geometry a is covered by geometry b -> intersection is geometry a</li> <li>geometry b is covered by geometry a -> intersection is geometry b</li> <li>geometry a does not intersect geometry b -> intersection is empty geometry</li> </ol> <p>This kind of question comes up a lot: As discussed in stackexchange <a href="http://gis.stackexchange.com/questions/31310/acquiring-arcgis-like-speed-in-postgis/31562" target="_blank">Acquiring ArcGIS speed in PostGIS</a></p> Continue Reading by clicking title hyperlink .. PostGIS Day Hang-out Panel discussion 2013-11-21T00:00:00+00:00 2013-11-21T00:00:00+00:00 http://postgis.net/2013/11/21/postgis-day-panel Regina Obe Regina Obehttp://postgis.net <p>November 21st, 2013 was PostGIS day and to celebrate we had a four panel discussion with host James Fee and panel members <a href="http://blog.cleverelephant.ca" target="_blank">Paul Ramsey</a>, <a href="http://www.linkedin.com/pub/bborie-park/54/a16/b7b" target="_blank">Bborie Park</a>, <a href="http://smathermather.wordpress.com" target="_blank">Stephen Mather</a>, and <a href="http://www.databasesoup.com/" target="_blank">Josh Berkus</a>.</p> <p><a href="http://www.youtube.com/watch?feature=player_embedded&v=xzl6gaOsasE" target="_blank">Video here</a></p> Continue Reading by clicking title hyperlink .. PostGIS 2.1.1 Released 2013-11-08T00:00:00+00:00 2013-11-08T00:00:00+00:00 http://postgis.net/2013/11/08/postgis-2.1.1 Paul Ramsey Paul Ramseyhttp://postgis.net <p>The 2.1.1 release of PostGIS is <a href="http://download.osgeo.org/postgis/source/postgis-2.1.1.tar.gz">now available</a>.</p> <p>The PostGIS development team is happy to release patch for PostGIS 2.1, the 2.1.1 release. As befits a patch release, the focus is on bugs and breakages.</p> <p>Best served with a bottle of GEOS 3.4.2.</p> <p><a href="http://download.osgeo.org/postgis/source/postgis-2.1.1.tar.gz">http://download.osgeo.org/postgis/source/postgis-2.1.1.tar.gz</a></p> Continue Reading by clicking title hyperlink .. pgAdmin shows no data 2013-10-05T00:00:00+00:00 2013-10-05T00:00:00+00:00 http://postgis.net/2013/10/05/tip_pgAdmin_shows_no_data Regina Obe Regina Obehttp://postgis.net <p>Every one or two months, someone asks on the PostGIS users list usually somewhat panicked, <em>My geometry is missing when I look in pgAdmin III</em></p> <p>This is documented in the PostGIS Frequently Asked questions section of the manual <a href="/docs/manual-dev/PostGIS_FAQ.html#pgadmin_shows_no_data_in_geom" target="_blank">I tried to use PgAdmin to view my geometry column and it is blank, what gives?</a></p> <p>Since this question gets asked so much, I thought it best to highlight it again.</p> <p>Spatial objects can be big things and if your geometry, geography, or raster row field is big enough, pgAdmin is not going to load it and will just show an empty field. This is by design. There are a couple of ways to verify you really have data and even how big your geometry, geography or raster column is</p> Continue Reading by clicking title hyperlink .. PostGIS 2.0.4 Released 2013-09-06T00:00:00+00:00 2013-09-06T00:00:00+00:00 http://postgis.net/2013/09/06/postgis-2-0-4 Paul Ramsey Paul Ramseyhttp://postgis.net <p>The 2.0.4 release of PostGIS is <a href="http://download.osgeo.org/postgis/source/postgis-2.0.4.tar.gz">now available</a>.</p> <p>The PostGIS development team is happy to release patch for PostGIS 2, the 2.0.4 release. As befits a patch release, the focus is on bugs and breakages.</p> <p>Best served with a bottle of GEOS 3.3.9.</p> <p><a href="http://download.osgeo.org/postgis/source/postgis-2.0.4.tar.gz">http://download.osgeo.org/postgis/source/postgis-2.0.4.tar.gz</a></p> <p>Doc downloads: <a href="http://download.osgeo.org/postgis/docs/doc-html-2.0.4.tar.gz">html doc download</a> <a href="http://download.osgeo.org/postgis/docs/postgis-2.0.4.pdf">pdf doc download</a></p> Continue Reading by clicking title hyperlink .. ST_Transform and ST_SetSRID: To project or not to project? 2013-08-30T00:00:00+00:00 2013-08-30T00:00:00+00:00 http://postgis.net/2013/08/30/tip_ST_Set_or_Transform Regina Obe Regina Obehttp://postgis.net <p>People often get confused between the <a href="/docs/manual-dev/ST_Transform.html" target="_blank"><code>ST_Transform</code></a> and <a href="/docs/manual-dev/ST_SetSRID.html" target="_blank"><code>ST_SetSRID</code></a> functions.</p> <ol> <li><p><code>ST_SetSRID</code> doesn&#8217;t change the coordinates but adds meta data to state what spatial reference system the coordinate actually are. If you stamped your WGS 84 long lat data as a meter based projection. Guess what? Its still long lat. A spade by any other name is still a spade so don&#8217;t use ST_SetSRID and expect to magically get meter coordinates.</p></li> <li><p><code>ST_Transform</code> is used to change the underlying coordinates from a known spatial reference system to another known spatial reference system.</p></li> </ol> <p>In PostGIS 2+ it&#8217;s pretty easy to correct mistakes you&#8217;ve made with standard ALTER TABLE commands. We&#8217;ll demonstrate a couple of scenarios</p> Continue Reading by clicking title hyperlink .. Distance proximity: Use ST_DWithin not Distance 2013-08-26T00:00:00+00:00 2013-08-26T00:00:00+00:00 http://postgis.net/2013/08/26/tip_ST_DWithin Regina Obe Regina Obehttp://postgis.net <p>If you have a problem that involves finding the things within X distance of other things or finding what things have nothing within X distance do not use <code>ST_Distance</code> for filtering and also do not try to use <code>ST_Intersects + ST_Buffer</code>.<br /> Use <a href="/docs/manual-dev/ST_DWithin.html" target="_blank"><code>ST_DWithin</code></a> instead. Why?</p> <ol> <li><p><code>ST_DWithin</code> can use an index and <code>ST_Distance</code> can not</p></li> <li><p><code>ST_Buffer</code> is just an approximation of a buffer and not an exact buffer</p></li> </ol> <p>Also note that <code>ST_DWithin</code> is supported for both geometry and geography.</p> Continue Reading by clicking title hyperlink ..