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

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PostGIS Nearest Neighbor query performance - can it be quicker?

I want to canvas the community to see if my nearest neighbor query can be optimized at all. I am happy with my current results, but I'm always up for improving. I have 2 tables, lakes and towns. I ...
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50 views

Mapnik3 + python3 + Postgis

I've installed mapnik3, python bindings, and postgis (and imported a pbf file into postgis), and can't seem to even make it generate a simple map as a png file. Specifically - where can I find ...
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Interative raster with PostGIS

I'm searching some solution to show raster layers from PostGIS on a Web Page. I need a solution to build a interactive map showing the values of my raster data when the user to click on pixel of the ...
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I am using an example fracnsites to make a similar map but I don't under stand the ajax code?

I am using an example fracnsites to make a similar map but I don't under stand the ajax code? The example has js code: var map, fields = ["gid", "createdby", "featname", "feattype", "status", "acres"...
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QGis Graphic Query builder for PostGis

My question is about availabe QGis Plugins that could help me with the following issue: I have a PostGis database that has one shapefile as a main table and a lot of tables containing the shapefile's ...
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How to publish PostGIS Rasters in Geoserver?

How to publish PostGIS Rasters in Geoserver? gdalinfo landsat.tif Driver: GTiff/GeoTIFF Files: landsat.tif Size is 1773, 1428 Coordinate System is `' Origin = (177595.474744186009048,471385....
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Missing vector features when import from .sqlite to postgis?

I imported vector data from a .sqlite file to PostGIS but not all of my vector features imported. I haven't been able to determine a reason for most of the loss of features between the databases (...
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How to query raster in PostGIS within GeoJSON mask only

I have a raster in PostGIS which I need to query pixel values from, but only within a specific area. So I have a GeoJSON polygon within which I want to extract min/max/avg values of the raster from. ...
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Single WMS pgRouting Layer from Array of Lat Longs

I am using the following loop for displaying the a bus route. 'stopLonLat' is a JavaScript object with all the latitude and longitude values of various bus stops. Since I am not looking for shortest ...
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importing shapefile in postgres

I am trying to import a shapefile to my database in postgres but there is no shapefile loader appearing in the plugin menu in PgAdmin. Postgis is definitely installed as I have added it as an ...
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30 views

How to get all pixel values of raster within a GeoJSON FeatureCollection in PostGIS

I need to extract all pixel values in a raster within a GeoJSON mask, using ST_Intersects. Attempt (throws invalid GeoJson representation): select row_to_json(t) from (select * from table_name where ...
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21 views

Modifying PostGIS database using geoserver

I want to build a mobile app using GeoServer and PostGIS database and I am little confused about how user will interact with database. I want end users to be able to upload new geospatial data to the ...
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Generate more nodes for routing

The following picture shows my routing database all set for querying loaded to QGIS. Red line is the road I want to select route from, yellow points are the vertices generated after running ...
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QGIS - Split a line having attributes with UNIQUE constraint

I am using QGIS with a PostgreSQL/PostGIS database, where the lines table (named 'segments'), besides the integer serial primary key, has a UUID column having a UNIQUE constraint. Trying to split a ...
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27 views

How to pass time dimension to postgis DB layer WHERE clause in Geoserver?

I have successfully configured a layer with time dimension that is backed by an SQL query to a PostGIS DB. I can query it through WMS, but I just can't find a way to pass the start and end time to the ...
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How to batch create GeoServer stores for each user?

I have unix system with a number of regular users, each with his/her own database in PostGIS. I need to create a PostGIS store for each user. I know how to do this in the web interface. Is it ...
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50 views

Is it necessary to use hibernate-spatial for postgis?

I'm beginner in GIS. I have a database in PostgreSQL that contains a table location, that table contains a column with type point. I have to get points and display it on google map. Once I did the ...
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like finding errors overlap on the same layer in postgis?

After meeting the overlay erroneous polygons in the same layer, I used the following query: select gid from limite_localidad where not ST_Overlaps(the_geom,the_geom) I have to leave 108 records ...
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pgRouting “Can't find Table”

I am using pgRouting version 2.1.0. I am using pgAdmin III. I have created a street network using Anita Graser's guide: https://anitagraser.com/2013/07/06/pgrouting-2-0-for-windows-quick-guide/ But ...
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How to add large file (in GB) in Xcode project?

I am working with Mapbox Framework. I have generated MBTiles file which I want to use in my project (for iPhones and iPads) but that file is having size of 3GB (which I can't use in project). When I ...
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31 views

Python GDAL open dataset in PostGIS with quotations

Error trying to use gdal to open a dataset in PostGIS with the following code: ds = gdal.Open("PG: dbname=nyc host=localhost user=postgres password=mypassword port=5432 mode=2 schema=public column=...
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PostGIS Svg Projection on Google Map

Context I have a database with spatial data such as areas and points. Some of the areas in my db are coming from OpenStreetMaps, representing some regions. (Which are kinda small at earth's scale, ...
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Finding the shortest path between points to LineString PostGIS

I have a MultiPolygon. Something like this: All one colored circles make up one multipolygon. I would like to find the shortest line to connect all one colored polygons. The first idea was to find ...
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Configure new SQL view doesn't appear for different DB's in the same PostGIS Database

I have PostGIS Database with different DB's. Each one of them has different workspace:store in Geoserver. When I'm opening Create new layer page and picking different workspace:store for some of them ...
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Cursor help on large spatial query in PostgreSQL

I have two very large tables on which I want to perform a spatial query. UPDATE table_a SET att_1 = b.att_1, att_2 = b.att_2 FROM table_a AS a JOIN table_b AS b ON ...
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51 views

Optimize Postgis contour lines DB

I'd like to try to optimize a world-wide 10m contour lines (isohypses) Postgis database(from SRTM). The complete DB takes 504GB on disk, contour lines are already in epsg:3857, and simplified with ...
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30 views

Saving styles to database

In QGIS, the option to save the style to a database (postgres) does not appear in the drop down list if the postgis table has been opened using add vector layer and then entering the postgres database ...
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29 views

How can I use ST_Contains/ST_Overlaps with non-simple lines?

Following the SQL of the accepted answer to How to get smallest line segments from intersection + difference of multiple overlapping lines? copied below. I'm having some difficulties assign the ids of ...
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Is PostGIS / PostgreSQL UK Public Sector Network (PSN) compliant?

Is PostGIS / PostgreSQL UK Public Sector Network PSN compliant? ... specifically so it can be used in a UK local government council?
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PostGIS: intersection of a MultipolygonZ and a floating point raster

I am trying to isolate the pixels in a floating point raster (loaded in PostGIS) that intersect my MultipolygonZ table (also loaded in PostGIS) and whose values are less than or equal to the z values ...
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88 views

How to IDW interpolation in PostGIS

I'm trying to find PostGIS Raster functions supports the Inverse Distance Weighted interpolation method (IDW) and Kriging interpolation method. I'm especially trying to generate a temperature map ...
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58 views

Copy Polygon to Postgis from Shapefile

I have the following situation: Postgres database with PostGIS There is a table with a PostGIS geometry column. All non geometry data is managed (create, update, delete) by a webapplication. QGIS ...
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Problem with ST_Union

I have loaded some rasters into Postgis. I did a lot of ST_XXXX (scale, snap to grid,resample) magic to make them aligned. After executing: select r1.rid,r2.rid ,ST_NotSameAlignmentReason(r1.rast,...
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How to use the TopoViewer in the QGIS DB Manager?

I'm just wondering what the TopoViewer in QGIS is doing. DB Manager (PostGIS) says 'Schema "schemaname" is not registered in topology.topology'. Unfortunately there is no help available and I can't ...
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28 views

Incorrect results returning from st_distance_spheroid query

Given a routable network table constructed by completing the guide at http://anitagraser.com/2011/02/07/a-beginners-guide-to-pgrouting/, how can I get an accurate list of all roads that are within a ...
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44 views

Are GIS tools suitable for physical capacity and placement management?

I'm a complete newbie to GIS systems, I've been watching some introductory videos about GIS but I'm not yet sure if GIS tools are the right tool for solving my problem. I have a database with ...
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39 views

update query with st_intersects() is not finding results

So I am trying to identify which items from the requests table fall into some particular district from the district table using postgis. Basically, I am writing an UPDATE query that will take the ...
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32 views

PostGIS Street Intersection Autocomplete with full text search

What I'm attempting to do is create a custom autocomplete for addresses, road intersections, POI's, etc. For now we are going to using Mapbox GL (we'll be creating a custom map at a later phase), ...
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Django/PostGIS: How to insert coordinates in PointField in EPSG:27700, and return EPSG:4236?

I am using Django 1.9 with PostGIS. I have input data that consists of British National Grid eastings and northings, and a table that looks like this: class Org(models.Model): name = models....
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63 views

Problems using pgr_fromAtoB - postgresql error

I have some trouble with the pgr_fromAtoB function of the workshop. I get: ERROR: column "ways" does not exist But "ways" is the table, not a column. What am I do wrong? My table ways looks like: ...
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43 views

PostGIS query: filter rows by area?

I am working with PostGIS (in CartoDB). I want to find all rows in the database with an area of over 100 square metres. I've been trying this: SELECT *, ST_AREA(the_geom::geography) AS area ...
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51 views

Import raster using raster2pgsql with out-of-db option not working

I am using raster2pgsql to import DTED data into postgis database. I would like the data to be out-of-db, I am using the command as follows. raster2pgsql -R /home/gis/elevation/DTED/area.dt2 public....
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ST_Intersects in postgis

My version : postgres 8.4.1/postgis 1.4.0 I want to perform a simple spatial join with the following query : SELECT code_insee, nom, id_canton, lib_canton FROM localisants.alca_toponyme_commune ...
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29 views

St_intersects returning false results in postgis

I want to intersect point geometry with raster. In postgis I'm executing select st_intersects(geom,rast) from testraster1,pft_pft and the result is false even though the points are sitting on ...
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QGIS crashes when using PostgreSQL/PostGIS triggers

When using PostgreSQL/PostGIS triggers saving layer edits gets slower and slower every time when saving a layer edit. This issue occurs after a few up to a few dozen saved layer edits. Finally QGIS ...
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PostGIS: Find nearest point given coordinates from another table

So I have two tables, one table is called stores which has the name of the store as well as the geom column that contains the coordinates for the stores. The other one is customers which has the ...
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pgrouting pointAtoB function

Has anyone successfully implemented pgr_fromAtoB function? Sometimes I get 0 results from points in the same line string, sometimes I do get results, How can accuracy be improved?, or maybe do I ...
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157 views

Visualizing shapefiles on web using SHINY package of R with PostGIS?

I am using PostGIS database to store my shapefiles. Now I want to read those files through shiny package of R. How can I visualize those files on web using shiny package of R and perform statistical ...
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How to calculate multiple distances between set of points and vector grid in PostGIS?

My set contains the following input data: A set of points and a hexagonal (vector) grid. For each cell in the grid, I want to calculate the driving-distance to each point. I thought this would be a ...
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59 views

Length not respected in ST_Segmentize

When segmentizing a geography line in Postgis, the max segment length does not seem to be respected when the line is more than 3000km. The error grows when the length of the line increases. Below the ...