PostGIS is an extension for the PostgreSQL object-relational database that adds support for geographic objects.

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N Nearest Neighbours efficiently PostGIS/Python

The data is worldwide about a million points, lat/lons, with an id and an importance value (0.0 to 1.0), and it's limited to being on land. Ideally I need to cluster all 1 million points into 100,000 ...
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156 views

Is it possible to create an ellipse around a line in 3D space?

In Postgis 2.1.1, I have a line in 3 dimensional space connecting two antenna points on the earth's surface. Is it possible to create an ellipse around that line? I have a formula to compute the ...
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171 views

Determine PostGIS geography polygon orientation

How can you determine the orientation of a PostGIS geography polygon? I'm looking/hoping for a function that would tell me which side is the interior (left or right) as you traverse the vertices of ...
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343 views

Postgis / QGIS Snap Point to Line

I'm trying to snap points to lines in postgis for use in QGIS, but cannot get it to work. I have one line in my line table (although it was created by merging multiple lines together) and about 600 ...
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93 views

Use of postgis with hibernate

We have an existing postgis database. Our application is developed in Java, but queries database through a jni dll, which appears to be not very effective for our purpose. I've managed to migrate to ...
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492 views

Rotation by attribute in Geoserver SLD style

I have a table with field calculated by function: NEW."rotationAngle" := degrees( ST_Azimuth( ST_StartPoint(NEW.the_geom) ...
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119 views

How to get the nearest points from pgrouting linestring result?

I'm trying to get the points or landmarks near from the result of pgrouting linestring( the shortest path ). I'm using OSM map entities and working with planet_osm_point. Here's my codes. SELECT ...
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71 views

Weird-looking France after OSM import with osm2pgsql

After importing france-latest.osm from Geofabrik, using osm2pgsql, it seems that the polygon attributed to Metropolitan France (osm_id = 1403916) is a bit odd: I'm far to be a geography expert, but ...
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139 views

How to calculate bus route transfer by using pgrouting?

Let say I have route 1 from A -> B -> C, route 2 from C -> B -> D, how can I write SQL for pgRouting which can let me have the result route 1 -> route 2 when I want to get the shortest path from A ...
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152 views

How to export postgis points as blocks in dxf with ogr2ogr

I'm trying to export postgis points as blocks to DXF format. I have a simple table in postgis with columns: CREATE TABLE pod_com_azimuth ( ogc_fid integer, rotation double precision, pointtype ...
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40 views

PostGIS query with input from point layer

I have a table of rivers in PostGIS, each river linking to its outflow. I also have a QGIS layer of some selected sources, and would like to select the entire river downwards from each source (i.e. ...
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295 views

Can't see Postgis layers added to QGIS

I'm trying to transition from an old Postgres/Postgis database to a new one. I'm working in a fresh install of Win 7 64 bit. I installed Postgresql 9.3 32 bit, then installed PostGIS 2.1.3. I created ...
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237 views

Collapse dual carriageway lines in PostGIS

I have OpenStreetMap data, which represents larger roads (e.g. dual carriageways, aka divided highways) as parallel lines. The question is answered for ArcGIS or Skeletron here, for example using ...
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283 views

TileMill Exports Failing

I'm having trouble exporting my map in TileMill (v0.10.1). I'm using OSM Bright with a PostGIS database connection to import OpenStreetMap data. When exporting an SVG or PDF through the user interface ...
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109 views

QGIS is not working with Postgres Plus Advanced Server

We have a problem to integrate GIS software with our GIS database which is populated on Postgres Plus Advanced Server 9.2 from EnterpriseDB. We are using QGIS to maintain and analyze our GIS ...
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544 views

how do I create a RESTful PostGIS web Service Framework?

I have PostGIS tables that store vectors that want to show on Google Maps. Read the post http://gis.stackexchange.com/questions/22354/how-to-display-a-postgis-table-on-google-maps But one thing that ...
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62 views

Import raster to postgis and add a foreign key constraint

I use raster2pgsql to import raster files into a table with this command line: C:\Program Files\PostgreSQL\9.3\bin>raster2pgsql -s 4326 -M -F -a c:\temp\mun.tif public.basqui_raster | psql -U ...
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174 views

Raster slightly displaced after exporting from PostGIS database

With the following queries I've exported a raster (GTiff) from my postgis database: 1.Creating a large object: WITH buffer AS ( SELECT id, ST_Buffer(geom,50) AS geom FROM ...
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77 views

PostGIS does not export shortest path to Shapefile

I am trying to draw a bunch of lines overlaying the globe map in a WGS84 projection. To this effect I have created a PostGIS DB with a table that has one column containing linestring data. My problem ...
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32 views

PostgreSQL : Question about dropping tables inside funtions

I am writing a PostgreSQL code where I have a function wich is used multiple times in a single query with different input values. Inside the function I create some tables and use them. What is the ...
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387 views

How do I catch PostGIS/PostgreSQL RAISE messages in QGIS?

I have a trigger set up in PostGIS/PostgreSQL which will show a RAISE WARNING when an inserted or updated polygon is within a certain distance of some predefined planning constraints. I want this ...
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268 views

PostGIS: How to distinguish overlapping routes (i.e., LineStrings) based on their direction?

I have a set of routes which are represented by LineStrings in my PostGIS database. These routes represent journeys that people make. I want to come up with routes that (a) overlap, and (b) have the ...
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139 views

How to set posgis default sequential value in a QGIS “editable” view?

Introduction In a QGIS project I have a VIEW, that I want to became editable (I'm trying to replicate the versioning system used DB Manager with some tweeks). Therefore I created a few rules to ...
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331 views

Publish existing table from postgis to geoserver

I would like to know if there is any way for publishing existing table from postgis to geoserver using Geoserver REST API or geoserver-manager java implementation. The thing is that i'm actually ...
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159 views

Trajectory Indexing: How could I store and index the large trajectory dataset generated by cars' GPS?

I have a large trajectory dataset generated by cars' GPS. Since I will do some data mining work on them, I need an efficient way to store and index them. I read some papers about Trajectory Indexing ...
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636 views

import esri Personal Geodatabase (.mdb) to PostGIS

I would like to import an esri Personal Geodatabase (.mdb) to PostGIS. I have tried to follow the blog post: How to import esri Personal Geodatabase (.mdb) to PostGIS on Linux I installed the GDAL ...
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79 views

Is there an ArcGIS to PostGIS function cross-reference table?

I was looking back at the presentation called "PostGIS Tips for Power Users" by Paul Ramsey and got to thinking... Has anyone ever seen an ArcGIS Geoprocessing Tool to PostGIS function cross-reference ...
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138 views

Using ST_Affine() and trans_param() functions on vector layer

After reading this post How to georeference a vector layer with control points? I decided to give it a try to move/rotation/scale a polygon using Postgis. I have two polygons, polygon_from and ...
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205 views

Styling river charts with TileMill - issue with filling a polygon made of disjoint line segments

I am trying to style inland river charts produced by the Army Corps of Engineers. I imported the vectors into Postgres, and I’m using TileMill to style the data. I am having trouble correctly filling ...
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49 views

Update PG table setting an area_id

I have a table with lots of points which I'd like to update and set a consecutive area_id to every point "group". I define a point "group" as points that are within a 500 meters radius. The raw table ...
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77 views

Geoserver Feature Versioning Support

I am creating a map feature editor that supports versioning & rollback using Geoserver as the WFS. From what I've read online, it seems Geoserver supports feature versioning. My question is how ...
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Migrating from PostGIS to Oracle Spatial

We are now using a solution based on PostGIS extension of Postgresql database for various spatial queries. But we are now thinking about data security. This is why we have a plan to migrate existing ...
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537 views

Smooth, not simplify, lines features in PostGIS

I'm trying to automatically generate paths to place labels on that follow the shape of rivers, 4wd tracks and other very windy lines. At first I thought the st_simplify() function was the answer, but ...
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92 views

Can't connect to WMS service? An Amazon-EC2 problem?

I'm running GeoServer 2.3.5 on a Windows instance in AWS for the first time. The data is on the server in PostGIS. The map layers have been published and I can see them locally without any problems. ...
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181 views

Spatial Precision for Editing in Multiple GIS Clients

I have something I'd like to discuss, I'll try to explain it first, why it's important, and I'll explain how ArcGIS handles the issue, which I think is a good way to handle it. Finally I'd like to ...
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152 views

Large buffers in PostGIS (5000 km radius)

I have a number of points stored as geographies in PostGIS (version 2.0.1), and I'd like to create rather large buffers around them (with a radius of 5000+ km). However, ST_Buffer doesn't handle this ...
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393 views

3D features (Polyline, Polygon) intersection library

For my research I am looking for a (python) library to get the intersection of some 3D features. The features can be Polygons or Polylines. Mostly I need to intersect a plane with my features and get ...
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203 views

get all the possible parameters of sql view

I have a Geoserver layer coming from a postGIS database. Among other attributes, I have one that is related to the date data we've collected, called departuretime. We use this attribute to display a ...
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107 views

Optimize ST_CoveredBy performance

I have a PostGIS 2.0.3 table with 113,862 records with multipolygons represented both as geometry and geography. There is a gist index on each of them. I'm running the following queries: SELECT *, ...
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2k views

How to install PostGIS and pgrouting on Windows if Stack Builder fails to connect?

I know this has probably been covered and that there are plenty of guides out there, but for the life of me I cannot get pgrouting installed. All guides/how-tos are different or assume prior ...
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589 views

Geoserver - empty native SRS field

I'm converting layers from shape files to postgis with the below command: shp2pgsql -s 22175 -c -W "latin1" path/file.dbf' table_name db_name | psql -d db_name Next, I add this layer to the ...
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137 views

Installing knn on PostgreSQL for windows

I am trying to install the extension KNN for clustering as an extension on my PostgreSQL database. I have downloaded the file http://www.pgxn.org/tag/analysis I found instructions on how to ...
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32 views

Spatial overlay data from many lines into a single line

Hello I have joined lines in my data set into longer lines (based on similar attributes) to reduce the number of rows in my data set. Now I want to take the information from the original smaller lines ...
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503 views

QGIS SPIT errors loading shapefile into PostGIS

With QGIS 1.8 on Windows 7, I just installed PostgreSQL / PostGIS and tried to load my first data into it, a shapefile using SPIT, but failed: ERROR: Geometry type (Polygon) does not match column ...
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Creating polygons for a choropleth map using PostGIS

I have a grid of points, each with a value to it as shown in the image below. The data was retrieved from PostGIS and rendered in Quantum GIS. The final result should be a polygons of a choropleth map ...
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120 views

Storing features in PostGIS and then creating layers using queries

I have a whole set of line segments or tracks that represent real tracks or, in some case, boundaries between areas. These segments form a network of lines on the map. I have a number of GIS layers, ...
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172 views

How to Create database using OGC compliant geometries and Custom type Geometries?

I am interested in storing geometry attributes in a PostGis database, so that it would be OGC compliant, along with OGC compliant geometry types like point,line, linestring, etc. I also wanted to ...
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129 views

Table for feature layer in PostGIS database cannot be published and enabled on GeoServer

I have tried to publish a table for feature layer in a PostGIS database to GeoServer 2.2.5. The layer was added and published. However, the layer has got a yellow exclamation mark in the "Enabled?" ...
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34 views

Automatic insert of project name into database

For every layer I've a field in my postGIS database that should be filled with the name of the current project and today I do this manually. Is there a way to do this with the Commands that can be ...
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668 views

How to merge linestrings which are connected with each other?

I would like to join linestrings which are connected to each other. The preferred output is a longer linestring based on all joined single linestings! The table that holds my single linestrings is ...