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

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Select query St_asBinary(rast) returns out of memory for query result

I have very large rasters (7000x3500 cells) in postgis (2.1.3) postgres (9.3.4) that I want to pull down via psycogp2 and create numpy arrays and ultimately a geotiff. Initially I found I had to use ...
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Why is the geometry changing slightly when I import shapes into a postgresql database with postgis?

I recently posted this question when first trying to import data from a file geodatabase into a postgis database: how can I maintain curves when converting from geodatabase to postgresql using og2gui ...
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In QGIS Python console how can I calculate given the distance, bearing and initial point, the final point

In QGIS Python console, how can I calculate the location of a final point, given a distance and bearing from an initial point? In PostGis I see that it is ST_Project, however I would like to do it ...
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47 views

Combine two parallel lines to one with postgis

In OpenStreetMap, a highway=motorway consists out of two parallel lines, each representing one direction: On a professional map the two lanes get combined to one single line and drawn with a middle ...
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osm2pgsql Ways importing very slowly in .pbf, much slower than .osm

I'm currently importing the planet-latest.osm.pbf file I downloaded from ftp://ftp.spline.de/pub/openstreetmap/pbf/planet-latest.osm.pbf some time last week. I'm importing it using the following ...
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ST_Intersects does not use spatial index

I wrote this part of code: SELECT CB.id_2 AS CountyID, CA.id_2 AS NeighbourCountyID FROM "Counties10B" CB,"Counties10" CA WHERE ST_Intersects(CA.geog,CB.geog); But it does not use spatial index. ...
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Import postgis layer from S3 link

I have a postgis layer (layer.sql), which I am trying to add to my postgres database (mydatabase). The postgis layer is stored on S3 (https://s3.us.../layer.sql). I can add the layer to my database ...
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56 views

Create HexBins for shapefiles

I usually create hexbins using the MMQGIS tools in QGIS. I would create a hex layer and intersect it with a shapefile. I've tried to create a hex shapefile and importing it into a PostGIS and tried to ...
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48 views

Postgis ST_Azimuth only returning a small range of angles

I have a puzzler with postgis and ST_Azimuth. I have a table of points (taken from country borders, and run through the QChainage plugin). I want to find the azimuth from a fixed point (15.0,50.0) to ...
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PostGIS: Compute isovist

I'm using PostGIS with OSM table of buildings. How can I compute isovist from single location point while only the buildings (represnted as geom's) are the obstacles. Thanks,
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PostGIS dijkstra routing - specifying source and target as bigint instead of int4?

I'm currently working on a problem where I have to use PostGIS's pgr_dijkstra to calculate the shortest route from a starting point to a destination, and then use ST_AsGeoJSON to convert the route to ...
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Shapely's object.project method dealing with overlapping polyline

So I am interested in knowing how far along a polyline a given point sits. Python's shapely package has a method to do such a thing, see the below code: from shapely.geometry import LineString ip = ...
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51 views

need to split some linestrings by points

please help me, i'm new in gis 1) i have а table with geom railways, which are multilinestrings (for example there are 2 ways one of which is interrupted, so this way will be multilinestrings ...
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19 views

Missing XML Attributes in Geoserver

I've imported a number of files that used to be in KML format into geoserver after putting everything into a PostGIS table. Now I would like to use CSS style information that was associated with the ...
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55 views

What solutions to use QGIS as insert tool for a Postgres relationnal database?

I have a Postgres/PostGIS relational database and I would like to use QGIS as an interface for inserting data. The thing is that my database is quite complex and I need my tool to handle the following ...
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Postgis ST_AsSVG renders a tiny SVG

I am storing information about a person's journey as a linestring. Having recently discovered ST_AsSVG I tried the following query: SELECT ST_AsSVG(path) FROM activities WHERE id = 209 ...
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61 views

Unable to load Postgresql spatial data in R (with rgdal)

I'm trying to load spatial data from a postgresql database in R, using functions from the package rgdal, but I'm having trouble getting the functions to work. For example, when trying to read a ...
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Enable PostGIS extension on Ubuntu 14.04.2

I have troubles enabling PostGIS extension on Ubuntu 14.04.2 and PostgreSQL 9.3. I have installed the packages with this step by step procedure. PostgreSQL and pgAdminIII seem to be installed ...
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Is it possible to perform spatial join in PostGIS and keep all features?

I am attempting to create an employment change map using a hex grid. I have individual establishment data as points with attached employment figures. When I ran the spatial join using the postGIS ...
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106 views

How to install PostGIS shp2pgsql-gui on openSUSE 13.2?

I installed PostgreSQL 9.4.4 together with pgAdminIII (1.20.00) and the PostGIS extension (2.1.7, via the Stack Builder) from http://www.enterprisedb.com/products-services-training/pgdownload on my ...
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48 views

how to create Topology table?

i have gis database called Madar in pgadmin with postgis and pgrouting extension, all the data inside gis database already inserted by shp2postgre tool , what i really need now is how to make topology ...
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Enable 3D viewer in geo explorer-geo server

I am trying to enable 3D viewer(google earth) in Geo explorer-geo-server by installing google earth plugin but doesn't work . any ideas ?
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PostGIS: intersection of a polygon with 2 rasters

I'm trying to get the intersection of a Polygon with 2 raster layers in PostGIS. The rasters have the same size and pixel size and I'd like to retrieve for the polygon a list of something like that: ...
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113 views

raster2pgsql error

I am attempting load ~500 rasters in a PostGIS table. They are .Hdr/.dat files. I am using raster2pgsql. I am able to load the first 260 rasters, but the remaining rasters fail with the following ...
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What is the fastest way to select oldest, unique geometry from a table containing duplicates in PostGIS?

I have an output from an ArcPy arcpy.Union_analysis operation and for the overlap polygons that were created I need to select out the oldest feature (along with the attributes). The result is 75740 ...
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Mirrored shape in postgis

I'm troubling with save of shapes in db. The shapes are steel sheet cuts, with may be holes, therefore are collections. I decided to solve to my self the problem, to allow the easy exportation between ...
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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. At 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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172 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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37 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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124 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

Merging DEM files using PostGIS

I have several DEM files and I want to merge them to create a mosaic. I found the St_Union(raster) or St_MemUnion(raster) functions but I don't know how to use them. Are there any other solutions?
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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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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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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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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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121 views

Why is mapserver returning a blank image?

I am trying to load a layer from a postgis database, mapserver does not return anything. I think I have narrowed the problem down to the fact that the sql query mapserver is running is returning ...
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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 ...
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34 views

Export only one value from a one-band raster

I have a PostGIS database with a georeferenced raster, with one band which contains values from 0 to 255. I should export it to a transparent GeoTiff picture in which the only visible pixels are those ...
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PostGIS TIGER reverse_geocode() returns state only

I have a clean install of PostGIS 2.1 in Postgres 9.3 on Ubuntu, using apt-get and postgres extensions. Ran the data loading scripts from here. normalize_address works well, but geocode returns no ...
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432 views

Export to shapefile error in QGIS from POSTGIS table

I am attempting to export a postGIS layer to a shapefile in QGIS 2.6.1 Brighton. The table has 244,674 rows. The data displays perfectly well in QGIS but when I attempt to export to shapefile I get ...
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110 views

Loaded OSM Data into PostGIS Database. Cannot view in ArcMap “The coordinate system identifier is invalid”

I loaded OSM File for Pennsylvania into a PostGIS Database in PostgreSQL using osm2pgsql. Everything seemed to go without a hitch until I finally connected to the Database in arcCatalog and tried to ...
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How to fix broken geometry after joining features in PostGIS

I have a PostGIS layer I'm serving over GeoServer. It looks like this. Im using the PostGIS query to get a new layer with some grouped features: SELECT id, name, st_union(st_buffer(geom, ...
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128 views

Calculate total line lengths within a polygon?

I have basically the same conundrum as How do i calculate line segment lengths within a polygon? but I'm working in PostGIS, not ArcGIS. Any pointers? This query seems to like it should work, just ...
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375 views

How to import country administrative boundaries from OSM Planet to PostGIS Polygons

I need to import all world countries as polygons or multipolygons into PostGIS. Specifically, I need the administrative boundaries that are like this orange bubble around the actual land borders. ...
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PostGIS Geography data type not displaying in QGIS

I am trying to display data held in the PostGIS Geography type on a map in QGIS. Whatever I do I can't get it to work. Here is the SQL that creates my data - a single point in London. CREATE TABLE ...
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Mapnik performance - large polyline dataset

I'm working with a very large set of polylines - contour data - to be rendered with Mapnik. (The contours are generated using gdal_contour from SRTM data.) At present I'm storing them in PostGIS and ...
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Geoserver - How to make a psql-backed timestamp that uses timezones

I'm working on an application that extends geoserver and am frustrated as I'm trying to define a SimpleFeature that has timestamps that include timezones. I've tried declaring my timestamp field ...
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Is geotools transformation of EPSG:3785 (Web mercator) to EPSG:4326 wrong?

Using postgres (9.3.6) and postgis: select st_astext(st_transform(ST_GeomFromEWKT('SRID=3785;POINT( 7550310.77 4139679.02 )'), 4326)); This returns POINT(67.8255956454323 34.8217133646348) Using ...
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Calculate surface map from PostGIS

We need to create surface maps from the website. The data is stored on PostGIS (2.1) as a table of Point geometries with a field indicating a thematic value. The optimal solution would be to produce ...
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Is there PostGIS equivalent to arcpy.sa.Slice() function?

I have an existing system built on an 8.3 PostgreSQL database which uses a ArcGIS - Spatial Analyst for a couple of raster operations. The system is moving to PostgreSQL 9.2 and I'm evaluating if the ...