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

learn more… | top users | synonyms

2
votes
0answers
151 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
128 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
306 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
156 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
74 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
441 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
625 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
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 ...
2
votes
0answers
28 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
406 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 ...
2
votes
0answers
114 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
150 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
107 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?" ...
2
votes
0answers
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 ...
2
votes
0answers
287 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
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 ...
2
votes
0answers
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?
2
votes
0answers
639 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 ...
2
votes
0answers
285 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
214 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
281 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
228 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
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" ...
2
votes
0answers
332 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
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 ...
2
votes
0answers
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 ...
2
votes
0answers
402 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
522 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
11 views

simplify tiled geometries while preserving anything on the edge

I have a dataset of polygons split into evenly sized tiles. How can I go about simplifying them, but not along the tile edges, so that there aren't any gaps between continuous features when the tiles ...
1
vote
0answers
7 views

SLD styling rule for first and last geometry feature in PostGIS table

Writing a SLD file to style a Points layer which I publish as WMS with GeoServer, is it possible to specify a rule that is only applied to the first and last features in the underlying PostGIS table? ...
1
vote
0answers
21 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 ...
1
vote
0answers
26 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 ...
1
vote
0answers
26 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 ...
1
vote
0answers
8 views

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 ...
1
vote
0answers
21 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 ...
1
vote
0answers
38 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 ...
1
vote
0answers
22 views

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, ...
1
vote
0answers
22 views

Creating geodjango model with geometry field that can accept different projections

I am working on web application with GeoDjango and within the model (db table) RoadAxis I have geometry field or more precisely LineStringField where I need to store different polylines (road axis) ...
1
vote
0answers
55 views

Import shapefiles into PostGIS using Python with psycopg2

I want to import shapefiles to PostGIS using Python with arcpy & psycopg2 to connect to PostGIS. I don't want to use the existing shapefile loader nor ogr, just write my own import tool. My steps ...
1
vote
0answers
28 views

suitable column Data-type for geojson data storage and processign in PostGis

I have a MySQL table with 2 columns, id, a unique geometry id, and GeoJSON stored as a varchar, eg, {"type": "Point", "coordinates": [116.4, 45.2, 11.1]} ...
1
vote
0answers
16 views

set Default projection in postgis table

I've set the SRID 4326 for a table having geometry column, but when i insert a geometry without SRID, i get an error because no SRID specified is interpreted as -1 or 0, so how i can set a default ...
1
vote
0answers
34 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 ...
1
vote
0answers
73 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. ...
1
vote
0answers
39 views

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 ...
1
vote
0answers
34 views

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 ...
1
vote
0answers
16 views

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 ...
1
vote
0answers
31 views

PostGIS is not seeing any GDAL drivers

I've tried setting POSTGIS_GDAL_ENABLED_DRIVERS=ENABLE_ALL as an environment variable. As well as running SET postgis.gdal_enabled_drivers = 'ENABLE_ALL'; from psql. (With a pg_ctl restart after each) ...
1
vote
0answers
55 views

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 ...
1
vote
0answers
43 views

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 ...
1
vote
0answers
59 views

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 ...