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

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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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185 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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346 views

Smoothing Lines in PostGIS

I want to smooth Lines in postgis, to be more specific, I want to smooth road data from OpenStreetMap. Basicly I thought of something like this scenario. This would be a possible road segment. I ...
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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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47 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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397 views

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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422 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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74 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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159 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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130 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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319 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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159 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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79 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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462 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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657 views

Clustering table on geohash index and geohash ordered table

I wonder if there could be a performance gain to re organize the rows in a table by Geohash and then CLUSTER this table on the Geohash index of the geometries. CREATE TEMPORARY TABLE tmptbl AS SELECT ...
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124 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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29 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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429 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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115 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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152 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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110 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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293 views

Different results given by PostGIS and MySQL?

I'm developing a spatial database of administrative areas. I started out with PostGIS, but as MySQL is being used in our other projects, I thought I would at least try to create a spatial-enabled ...
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192 views

Projecting PostGIS in Openlayers

I have a layer(base layer) with MultiLineString Geometries and now I need to project the layers(overlays) in the base layer from PostGIS using OpenLayers. However, I got an idea how to project table ...
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47 views

Is it possible to permanently save the Edit Widget for a Postgis layer?

Is there a way of configure the editing type for a POSTGIS layer through Edit Plugin and do not lose the changes after remove the layer or exit the program?
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658 views

why preview image is blank for ImageMosaicJDBC (postgis raster) layer?

I follow http://docs.geotools.org/latest/userguide/library/coverage/pgraster.html to publish a ImageMosaicJDBC layer in geoserver. the layer seems published ok and saved, but the preview of this layer ...
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290 views

From pgRouting shortest_path back to osm node id

I'm successfully performing path finding queries like shortest_path on data imported with osm2pgrouting. The tables I have inside my pgrouting DB are the following: List of relations ...
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219 views

Error recognising password; importing OSM to PostGIS in QGIS

When selecting OSM Tools (Import into PostGIS) , attching my .osm file in the Input option, selecting my OSM Database, and then clicking run, I am prompted to enter a password for connection. "Enter ...
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283 views

Postgresql Query Plugins Not Returning Results in QGIS

I'm using the Fishnet function as described here to create a grid. If I use the following SQL to call the function to position a grid where I want it (I'm using NZGD2000 SRID = 2193) the query ...
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232 views

Displaying text from dxf in Openlayers

I managed to import .dxf into Postgis table, and now have, among others, rows with Point geometries and values in text column (which corespodent with Label values from ACAD .dxf). What is the best ...
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92 views

MultiPolygon from database

I would like to know how to create an instance of a Multipoint from a PostGIS database.. I do the query , then got the ResultSet named "area" , the column with MultiPolygon attributes is named "geom" ...
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339 views

Parcel ID Mapping (brainstorming)

In my project I have a table full of residential properties by Parcel_ID. Table 2 is a TIGER streets shapefile. I would like to build a query in MS Access displaying all properties within a mile ...
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98 views

network related issues arising when running an arcpy script

Essentially I wrote an arcpy script that is within a toolbox that I ported over to a different machine to test out after the script worked locally. The script essentially utilizes the psycopg module ...
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108 views

Symbolizing Layers from a PostGIS Database to many Client Computers

I was hoping someone could help with a symbolizing issue. I have a PostGIS database on a server with a number of layers. The layers of a series of polygons, lines and points that all share the same ...
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405 views

line segments using points

Is there a way to get line segments from a linestring using points with lat/lng coordinates? ST_Line_Substring is taking float8 start/end points. Is there a way to replace the float8 with lat/lng? I ...
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534 views

Arc by center point in PostGIS does not fit the circle

I'd like to store a GML ArcByCenterPoint in PostGIS. I can work out the start, middle and end points required by the CIRCULARSTRING type and all seems to be OK, except that when I visualise the arc it ...
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12 views

Optimize PostGIS query, ST_Intersects - Raster and Geom

I am trying to run a spatial query between two tables. Table one (prism_ppt_monthly - see below for details) is monthly precipitation data. Table two (usgs_basin_boundary - see below for details) are ...
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14 views

Make a line from a set of GPS points close to a specific GPS point with PostGIS

I have to develop a map-matching algorithm. By the moment I only match gps points with the closest road segment. I'm looking for a way to compare the directions between a gps point and a road to ...
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22 views

Creating quadtree index on latitude, longitude data in PostGIS

I have a table of locations in which one of the columns represents the lat-long for the location. These coordinates have been extracted from the OpenStreetMap file. How can I create a quadtree index ...
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17 views

How does `ST_Union` treat NULL values in a raster?

My question is about how ST_Union of rasters containing NULL values are handled. For example suppose I have two rasters that intersect but the values of the intersection are NULL in one of the ...
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57 views

Help serializing a postGIS query to geojson

I have a query which I would like to serialize to geoJSON: select article_title, pub_date, city, geom from article, location where article.id = location.id; I can serialize the geom field easily ...
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34 views

OSM Bright Cartography XML

So I've successfully setup a tile server as described here: https://switch2osm.org/serving-tiles/manually-building-a-tile-server-14-04/ What's troubling is the lack of clarify surrounding OSM Bright ...
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23 views

Displaying multiple features from a geoserver layer with time and style in a KML

I have 4 datasets organized in a PostGIS database each of the same geometry and location except they are at different times. They each have a corresponding datetime field. I can load these into a ...
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17 views

Selecting all pixels above a given value in a raster in PostGIS

I have a raster with one band whose value represents the date of the occurrence (a sequential integer). This raster file gets updated regularly, and each time that happens, I need to run a process ...
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63 views

Rendering TopoJSON in Leaflet from GeoJSON PostGIS output?

I'm using the query found here SQL query to have a complete geojson feature from PostGIS to get a geojson that I can display on a leaflet map. However, the amount of data is kinda big and the ...
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21 views

Merge raster tiles in PostGIS

I have several raster tiles that are adjacent and non-overlapping, so they form a mosaic. I am trying to merge two adjacent rasters using PostGIS but am getting an error that they do not have the same ...
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63 views

How to create line segments between pairs of pixels in a raster?

I want to draw several lines between pixels (please see the image below) according to some criteria : First Criterion: The distance between 2 pixels is less than 2000m and greater than 500m ...
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28 views

Server-side map generation from postGIS database

I have loaded some OSM data into a postGIS database, using imposm. Now using this data base, I computed a value associated to every point of the map (could be anything, real-estate average price or ...
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31 views

OS Terrain 50 into Postgresql/PostGIS for lat/long analysis

I am performing analysis using line of sight's and followed a very useful blog post at http://davidrowley.blogspot.co.uk/2013/08/calculating-line-of-sight-with-postgis.html which detailed how to load ...