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

learn more… | top users | synonyms

2
votes
0answers
266 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 ...
2
votes
0answers
47 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. ...
2
votes
0answers
131 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 ...
2
votes
0answers
93 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 ...
2
votes
0answers
213 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 ...
2
votes
0answers
132 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 ...
2
votes
0answers
54 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 *, ...
2
votes
0answers
295 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 ...
2
votes
0answers
403 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 ...
2
votes
0answers
105 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 ...
2
votes
0answers
25 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 ...
2
votes
0answers
107 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, ...
2
votes
0answers
112 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 ...
2
votes
0answers
265 views

working with multiple wfs-t layers

I am using multiple wfs layers and using editing tools in that like edit,draw,save etc. The code is shown here...... var district = new OpenLayers.Layer.Vector("district(wfs)", { ...
2
votes
0answers
33 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 ...
2
votes
0answers
253 views

How to import PostGIS layer with geography type to QGIS?

I tried to import in QGIS a layer from a PostgreSQL table with a geography type column created through the extension PostGIS. I noticed that QGIS doesn't seem to like the geography column... Here ...
2
votes
0answers
238 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 ...
2
votes
0answers
180 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 ...
2
votes
0answers
231 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 ...
2
votes
0answers
184 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 ...
2
votes
0answers
248 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 ...
2
votes
0answers
190 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 ...
2
votes
0answers
82 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" ...
2
votes
0answers
371 views

PostGIS: ST_Transform function conversion problem

I'm inserting map data from a GML file with srid EPSG:27700 into a PostGIS database table with srid EPSG:4326. I'm using the ST_Transform function as in this snippet: ...
2
votes
0answers
286 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 ...
2
votes
0answers
90 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 ...
2
votes
0answers
100 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 ...
2
votes
0answers
383 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 ...
2
votes
0answers
426 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 ...
1
vote
0answers
18 views

How can I associate a consistent polygon area with a set of attributes using a topology?

Consider the following topology. SELECT CreateTopology('topotestschema', 0, 0.01); CREATE TABLE topotest (id SERIAL PRIMARY KEY, data TEXT); SELECT AddTopoGeometryColumn('topotestschema', 'public', ...
1
vote
0answers
37 views

Join/append multiple, identical polygon layers into a single layer whilst retaining all attributes?

I have run some analysis (zonalstats) on different raster layers using the same analysis polygons. I want to concatenate all these different layers together, i.e. retain a single polygon and have a ...
1
vote
0answers
22 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 ...
1
vote
0answers
36 views

PostGIS - Intersects feature to split into linestring

I would like to know if it's possible to intersect feature datasets (multipolygon, polygon, multilinestring and linestring) to get a result as a set of linestrings being split at each intersection ...
1
vote
0answers
24 views

Postgis Raster Unions Color Issues

Can someone explain to me what I am doing wrong here as I think I do not properly understand postgis raster bands. I have a set of geometries that I want to merge with a raster and created a raster ...
1
vote
0answers
24 views

How to dissolve inner polygons in a multipolygon

I'm trying to get the boundary of a collection of zip codes. Here is my current sql: SELECT ST_AsText(ST_SimplifyPreserveTopology((ST_Union(geom)), .003)) as poly FROM zcta5_data WHERE zcta5 IN ...
1
vote
0answers
29 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 ...
1
vote
0answers
41 views

How to calculate the average distance among set of points as measure of closeness

I have three series (or tables) of points in PostGIS which I want to compare. I would like to know how "close" each series is when compared to the other two. In other words I would need some measure ...
1
vote
0answers
27 views

PostGIS Raster functions not working

Hopefully I have a simple question that I'm not phrasing correctly in google. I'm trying to learn about storing and producing rasters in PostGIS. There are tons of examples and documentation online ...
1
vote
0answers
50 views

Undefined symbol error when creating postgis extension

When trying to create postgis extension, I'm getting an error, no references in google on it. maptest=# CREATE EXTENSION postgis; ERROR: could not load library "/usr/pgsql-9.3/lib/rtpostgis-2.1.so": ...
1
vote
0answers
33 views

Debugging ogr2ogr “AddGeometryColumn failed” and “Terminating translation prematurely after failed translation of layer”

As noted in the title, I'm getting the following error: ERROR 1: AddGeometryColumn failed for layer pretty_polys, layer creation has failed. ERROR 1: Terminating translation prematurely after failed ...
1
vote
0answers
37 views

Merge overlapping GeoJSON GeometryCollections

I need to merge three overlapping GeoJSON GeometryCollections of Polygon. Ultimately, the end result needs to be a geom type for PostGIS (e.g. MULTIPOLYGON) so I can easily check if particular points ...
1
vote
0answers
38 views

Looking for free tools to automatically generate spatial data catalogue

I've recently inherited a whole bunch of spatial data (mostly shapefiles but some .gdbs) which relate to a bunch of different cities. I'm looking for a way to take an inventory of what data I've got ...
1
vote
0answers
33 views

Is there a Raster2pgsql GUI?

Has anyone ever attempted to create a raster2pgsql gui (like the shp2pgsql gui). As I am sometimes lazy to use command line, this could be a very nice to have.
1
vote
0answers
57 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 ...
1
vote
0answers
49 views

Add polygons to PostGres to be queried by Nominatim

I'm trying to build out a geocoder that also returns the correct legislative district information from this data: http://www.census.gov/geo/maps-data/data/tiger.html I've got OSM data imported into a ...
1
vote
0answers
79 views

Open PostGIS layer with QGIS 2.2

I just upgraded QGIS from 1.8 to 2.2 and I am getting some troubles to open a PostGIS Layer. The connection with the server works fine, I can see all my tables, select the one I want to open and even ...
1
vote
0answers
49 views

PostGIS raster connection is not closed by MapServer

I'm using PostGIS raster in MapServer like this: TYPE RASTER DATA "PG:port=6432 dbname='mydb' user='postgres' password='1234' schema='public' table='truemarble' mode='2'" PROCESSING ...
1
vote
0answers
43 views

Implement a least cost path in a graph

I am trying to produce a routing functionality in a web-GIS that, given a start and an end point, will retrieve the least cost path taking into account points along edges representing major costs, ...
1
vote
0answers
29 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 ...
1
vote
0answers
65 views

Gaussian plume model in PostGIS or geocouch

Does anyone know of existing code for dispersion modeling using Gaussian Plume or comparable model, that I could plug in / adapt to be used programmatically from PostGIS or alternatively via ...