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

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Routing in MS SQL 2012

I would like to perform routing in MS SQL 2012 similar to pgRouting. In pgRouting, I'd do the following steps to create a routable network: Create a database routing with template template_routing ...
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Identifying the cause of NOT ST_IsValid()

I have a table of raw GeoJSON in a Postgres database, with PostGIS installed. Some of this GeoJSON is unfortunately invalid, for varying reasons. SELECT id, name, geometry FROM shapes WHERE ...
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Split lines at intersections in PostGIS (must be simple but…)

I'm usually closer to my answer than now, but I've looked at all the answers here and couldn't adapt one to work on my data and I'm stuck. I have oriented polylines (Montreal's train network) and ...
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Improve speed of PostGIS “nearest neighbor” query?

One of the features of the Python/Django/PostgreSQL web application I'm building is that a user will be able to see the 100 other users who are nearest to them, sorted by distance. I'm using PostGIS ...
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Problem installing Aggregate Polygons Function in PostgreSQL 9.3

I'm new to PostgreSQL and I've been trying to run a sql function written by Dr. Horst Duester, found in http://www.kappasys.ch/cms/index.php?id=65&L=5, which is used to aggregate detached ...
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polygons and lines not drawn correctly (qgis+postgis)

i am really new to this so i could use some help.. i load osm file into postgresql and then i connect to the database with qgis t to plot it and i see this it happens to whatever file i import to ...
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68 views

QGIS/PostGIS layer styles

I've made a plugin asking for login credentials to a DB. Once logged in, the plugin is loading some layers from the DB. In the DB there are both admin and "normal" users. I've saved two styles to the ...
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35 views

Geoserver WFS Fails to Load in OpenLayers

I'm working with Postgis->Geoserver->openlayers on localhost. I followed a Geoserver tutorial to import some nyc sample data into my postgres/postgis database and link it to Geoserver. The layer ...
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ST_SplitRight() in PostGIS?

I am looking to split a shapefile via a line. I am interested only in the feature that lies to the right of the line; exactly what ST_SplitRight does here. Do any of you know of a way to do this in ...
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26 views

How to solve an instalation problem requiring “liblwgeom” to work with “shp2pgsql”

I am trying to import shape file to postgis. I have problem configuring shp2pgsql. I am getting this error : dyld: Library not loaded: @loader_path/../lib/liblwgeom-2.1.1.dylib Referenced from: ...
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PostGIS: calculate width/length of rectangular surface

I have rectangular shaped surfaces (multipolylines) and I need to calculate the width and/or length.. they have a rectangular shape but they're not real rectangles. Is there a way to do this ?
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Postgis add Geography to function()?

i was wondering im getting different results when using geography() on different positions within a query. So, whats the most accurate way of forcing geography() over a functions with geometry ...
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PostgreSQL : send all rows of a table to a function [migrated]

I have a table with one column (double precision numbers). I also have made a function (with double precision numbers as input and output), and I want to send every value of my table to the function, ...
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80 views

System requirement specification for Big Data Postgesql, PostGIS, and GeoServer based service

I want to start a GIS portal for around 3000-5000 visitors per day. MY database will be of an approximate size of 10 Terrabytes. The maps and layers are moderately complex, satellite-map overlay is ...
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32 views

PyQGIS loading layer style with PostGIS

I'm loading layer styles from .qml files in a Python plugin. I'm about to switch to loading them from a non-local postgreSQL db. I've been looking at the (from QgsVectorLayer (v2.2)) ...
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35 views

Increase Map Availability in Geoserver [duplicate]

I have an application which access same map from two geoserver using loadbalancing concept the map is accessed using WMS service. where the two geoserver connected to a single same POSTGIS database. ...
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56 views

What is wrong with how I am using ST_Within?

I am learning postgis 2.1. I created a postgis table from a shapefile and imported it into the DB. It made a table like this: db=# \d districts ... geog | ...
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can't geocode with PostGIS 2.1.1

I don't know where's the mistake... I am using the process from the PostGIS documentation (http://postgis.net/docs/manual-2.1/postgis_installation.html#loading_extras_tiger_geocoder) . I created a ...
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ESRI projection to SRID?

I am looking at MapX and MapY coordinates. The docs say they are "truncated State Plane coordinates: NAD 1983 State Plane Louisiana South FIPS 1702 (US Feet)." I am trying to reproject into a common ...
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Double version of PostGIS installed on my server

For some reason I messed up an installation of Postgis on my PostgreSQL 9.2.8 server. I had version 2.0.3 installed and when I tried to upgrade to 2.1 it did so. The problem comes when I dump the ...
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PostGIS 2.1 error install with shared object (rtpostgis-2.1.so") Linux Mint

I've Installed Linux Mint 16 mate and install PostGIS with PostGreSQL (I've tried many ways in the Internet from original source to some suggestion) but all is too error: " ERROR: could not load ...
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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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How to install PostGIS and OpenLayers plugins?

I am new to QGIS and have installed the QGIS v 2.2.0. For adding google map as a base layer I need to install OpenLayers plugin. I also need to add the PostGIS plugin for DB management purpose. Can ...
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POSTGIS: function st_collect(geography) does not exist

I am trying to use some Geography functions, but I am getting an error that (all) functions are not existing. I have checked other Stackexchange posts (e.g. this one), but the solutions did not work ...
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How <-> operator work?

I'm doing a search to find links close to a point. The problem is if i limit to 20 result i found the closer link at 6mts but if i limit to 10 result that link doesnt appear and the closest link is ...
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37 views

Can you do ST_Transform on geographies?

I am brand new to postgis. I just learned that geometries model simple cartesian objects and that geographies model shapes on the surface of the earth. I have a bunch of data in columns X and Y of a ...
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How can I GROUP BY linear spatial clusters with PostGIS?

I have a series of points in a horizontal line, arranged into discrete spatial clusters by the underlying data pattern. Here's an example of what they look like: How can I use PostGIS to group them ...
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22 views

Does the psql prompt have a working directory in the file system?

I am learning postgis. This tutorial says "Navigate to where you downloaded the shapefile." Does that mean navigate to this location in the #psql prompt or navigate to this location with the $propmt? ...
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63 views

How to add a Geoserver WFS layer with data imported from PostGIS to OpenLayers?

I know that there are very similar answers to my question but I just can't find how to solve this problem, so I am wondering if my case is different or if I am doing something wrong here. I am trying ...
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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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50 views

ST_NumInteriorRings not returns zero, is a bug?

I am using PostGIS v2.0.3, the guide say that ST_NumInteriorRings "will work with both POLYGON and MULTIPOLYGON types but only looks at the first polygon. Return NULL if there is no polygon in the ...
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PostGIS Type Modifier Error

I'm trying to work an example from the "PostGIS Cookbook" and I'm getting an error I don't understand. I'm running the example using Postgres.app on a MacBook. Postgres.app is running PostgreSQL ...
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PostGIS : check if 2 lines are at contrary sides of third line

I am looking for a workflow to select a line on the condition that it is located on the contrary side of a middle line. So there are 3 lines (2 are given, 1 I want to select). I don't need you guys ...
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34 views

PostGIS create read only user for QGIS

I am having issues reading spatial tables in QGIS with a select-only "reader" user. I can create the reader user to access regular postgres tables like this: GRANT USAGE ON SCHEMA test TO reader; ...
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How to speed up a query for nearest linestring to point data

I have processed a Strahler stream order layer with a lot of river linestrings (type: Multilinestring) and their corresponding strahler number (see information here). Besides I have a point layer. I ...
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Do ArcGIS clients that direct-connect to postgresql/postgis databases override configuration settings?

I went in to modify some settings on a Postgresql database via the PGAdmin config editor and some of the settings don't have their default values and they are higher because they've been overridden ...
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Osm2pgsql crashed on import. Can I continue with what has been imported so far?

I recently imported the osm planet file using osm2pgsql. The process crashed (hung my whole box) when creating the geometry indices and other indices on the tables. Scouring through the source code, ...
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PostGIS : I want to use ST_OffsetCurve with MultiLineStrings

I need to use the function ST_OffsetCurve for a multilinestring, but PostgreSQL gives me the error that the function is only for Linestrings. Is there a way arround? I want to use the function ...
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63 views

polygon from exterior points

How to convert points data to polygon, so as to form polygon from exterior point as shown above
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pgAdmin vs psql

I have downloaded postgreSQl 9.3 and Postgis 2.1 recently as an educational adventure and have been working with both through the pgAdminIII interface. I haven't used psql yet when working with my ...
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Update postgres/postgis point data attribute from another enclosed polygon shapefile in QGIS

I have a placename point table in postgis with 'district' column. a districts polygon shapefile with district name in 'Name' column. See the image below. I would like to update the 'district' ...
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42 views

Polygon feature in PostGIS

I have uploaded a feature to the PostGIS db and visualize it by mapguide. Now I would like to know how can I update (add) features from database directly. Can I add a new row from the web form ...
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Converting lat-lon from degrees and decimal minutes to decimal degrees in PostGIS [duplicate]

Creating a geometry in Postgis is fairly simple: ST_SetSRID(ST_MakePoint(longitude,latitude),4326); These lat/lon should be in decimal degrees format like 33.02505 -96.70668 Is there a ...
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77 views

GeoServer create layer from PostGIS (data type point)

(Several days ago a user on gis stackexchange suggest that I should use OpenGeo (I was using geojson before). I succeed at what I was doing at that time, but now I have a different problem.) I was ...
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Broken PostGIS support GDAL

I'm having some problems with Postgres/PostGIS after rebuilding my GDAL library:( I wanted to add MrSID support in GDAL so rebuilt it with the MrSID SDK. Everything compiled ok and I am now able to ...
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Connecting to PostGIS (LATIN1) from Microsoft Access 2010 - Encoding problem?

I want to connect to a PostGIS table Using MS Access. The table has been created using the PostGIS Shapefile loader in pgAdmin. It has been encoded at LATIN1 (it wouldn't load with UTF-8 default). I ...
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Problem with matching a buffer in Openlayers and the same buffer in PostGIS query

I am using a buffer tool to create a buffer on my base map in Openlayers. In addition to creating and visualizing this buffer, I pass the center point and radius to a query. The query collects all ...
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How to define Z dimension on table with PostGIS for import in TileMill?

I'm trying to reproduce the idea behind this blogpost from Mapbox, but with other data, for example the ne_10m_populated_places_simple dataset from Natural Earth. By adding a z-dimension to the data ...
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ST_ZMax() does not exist in PostGIS

I'm trying to follow this example on Mapbox blog, about using 3D shapes in PostGIS. The database-query is this: DROP TABLE tilemill_buildings; CREATE TABLE tilemill_buildings AS SELECT ogc_fid, ...
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Suggest an algorithm to measure how a node is connected to road network

I try to measure how well a node is connected to the rest of the network. If a city has a distant suburb connected with one sole road, it's connectedness is, say 1. If it's connected by 2 roads, it's ...