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

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Osm2pgsql crashed on import. Can I continue with what has been imported so far?

I recently imported the osm planet file using osm2pgsql. The process crashed (hung my whole box) when creating the geometry indices and other indices on the tables. Scouring through the source code, ...
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1answer
234 views

PostGIS : I want to use ST_OffsetCurve with MultiLineStrings

I need to use the function ST_OffsetCurve for a multilinestring, but PostgreSQL gives me the error that the function is only for Linestrings. Is there a way arround? I want to use the function ...
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1answer
233 views

polygon from exterior points

How to convert points data to polygon, so as to form polygon from exterior point as shown above
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2answers
672 views

pgAdmin vs psql

I have downloaded postgreSQl 9.3 and Postgis 2.1 recently as an educational adventure and have been working with both through the pgAdminIII interface. I haven't used psql yet when working with my ...
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1answer
247 views

Update postgres/postgis point data attribute from another enclosed polygon shapefile in QGIS

I have a placename point table in postgis with 'district' column. a districts polygon shapefile with district name in 'Name' column. See the image below. I would like to update the 'district' ...
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94 views

Polygon feature in PostGIS

I have uploaded a feature to the PostGIS db and visualize it by mapguide. Now I would like to know how can I update (add) features from database directly. Can I add a new row from the web form ...
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1answer
614 views

Converting lat-lon from degrees and decimal minutes to decimal degrees in PostGIS [duplicate]

Creating a geometry in Postgis is fairly simple: ST_SetSRID(ST_MakePoint(longitude,latitude),4326); These lat/lon should be in decimal degrees format like 33.02505 -96.70668 Is there a ...
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2answers
559 views

GeoServer create layer from PostGIS (data type point)

(Several days ago a user on gis stackexchange suggest that I should use OpenGeo (I was using geojson before). I succeed at what I was doing at that time, but now I have a different problem.) I was ...
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320 views

Broken PostGIS support GDAL

I'm having some problems with Postgres/PostGIS after rebuilding my GDAL library:( I wanted to add MrSID support in GDAL so rebuilt it with the MrSID SDK. Everything compiled ok and I am now able to ...
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1answer
255 views

Connecting to PostGIS (LATIN1) from Microsoft Access 2010 - Encoding problem?

I want to connect to a PostGIS table Using MS Access. The table has been created using the PostGIS Shapefile loader in pgAdmin. It has been encoded at LATIN1 (it wouldn't load with UTF-8 default). I ...
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1answer
227 views

Problem with matching a buffer in Openlayers and the same buffer in PostGIS query

I am using a buffer tool to create a buffer on my base map in Openlayers. In addition to creating and visualizing this buffer, I pass the center point and radius to a query. The query collects all ...
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1answer
119 views

How to define Z dimension on table with PostGIS for import in TileMill?

I'm trying to reproduce the idea behind this blogpost from Mapbox, but with other data, for example the ne_10m_populated_places_simple dataset from Natural Earth. By adding a z-dimension to the data ...
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1answer
143 views

ST_ZMax() does not exist in PostGIS

I'm trying to follow this example on Mapbox blog, about using 3D shapes in PostGIS. The database-query is this: DROP TABLE tilemill_buildings; CREATE TABLE tilemill_buildings AS SELECT ogc_fid, ...
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2answers
146 views

Suggest an algorithm to measure how a node is connected to road network

I try to measure how well a node is connected to the rest of the network. If a city has a distant suburb connected with one sole road, it's connectedness is, say 1. If it's connected by 2 roads, it's ...
3
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1answer
538 views

PostGIS - when I add a polygon, delete overlapping areas in other layers

I'm starting to work with PostGIS and I'd like to solve the following problem: In my database, I have multiple land use class layers, for example: "residential", "industrial", "commercial". The ...
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1answer
476 views

How to create a buffer on a linestring with varying or increasing/decreasing width

I want to buffer rivers/streams for a topographic map. I'm using a PostgreSQL/PostGIS database. Usually, I create buffer with ST_Buffer with a constant width. For example, the width of a river buffer ...
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67 views

How to SELECT one day's scene (Landsat 8 scenes)

I have a huge dataset of raster in PostGIS. Each scene is divided into tiles (tile-size 500x500). I was trying to SELECT rast FROM landsat8 WHERE ST_Intersects(rast, polygon). It runs very slow, ...
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1answer
169 views

Openlayers wfs no fid being passed from tinyows

I have a webapp - OpenLayers<->tinyows<->postgis. With 1 layer I have a problem. On localhost all works well - here is a snip of the xml I get back: <gml:featureMember> <tows:trad ...
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1answer
2k views

Import shp to Postgis using Python and ogr

I just export a Postgis Table to shp using this tips but I'm not able to import a shp to Postgis using the same library(ogr). Any idea? Thanks a lot f.
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1answer
508 views

QGIS loads PostGIS layers but DBManager can't connect

DB Manager can't connect to PostgreSQL, but "Add PostGIS Layer" can. My eventual goal is to save created layers to PostGIS. I assume I can do this using the DBManager Tool. I can alternatively use ...
2
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2answers
402 views

Export to Mapbox (TileMill) from PSD (or SVG/PNG)

Newbie question: I designed a map (not Earth-related) in Photoshop and I want to use something like Mapbox to serve the map and make it dynamic (bounding boxes, zoom in/out, etc). How can I go from an ...
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3answers
1k views

How to create random points in a polygon in PostGIS

I have a polygon layer, and would like to generate random points in each polygon. An initial searching in Google resulted this website which presents a function for this purpose: ...
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52 views

Using PostGIS to find airplanes flying on the same routes over the sea [duplicate]

I need to answer the following questions: 1-Given a database of all flights,including flight ID and the airplanes location (lat/long etc) taken at timestamps of constant 1 minute intervals, find all ...
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164 views

Adding GIS feature into an existing postgis table using django 1.6

i am using Django 1.6 on my web map. the problem i got is that i cannot import shapefile with features about 200. . the console has given me this traceback. . Saved: 162-05-0001-005-31 Saved: ...
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56 views

How can I determine which polygons contain other polygons?

I am using only free, open source tools. I have two shape files: a shape file of voting precincts and a shape file of census tracts. I want to know: which voting precincts fit inside which census ...
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189 views

PostgreSQL : total length of roads in polygon

I have 2 tables : wgo (lines) and wbn (polygons) With this code, I can display the length of each road inside a polygon. If I have a polygon with 2 roads in it, as a result I get 2 rows with the 2 ...
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1answer
282 views

Area of polygon split by a line

I need a query that return the area of two polygons that have been split by a line. This is what I did so far: SELECT ST_Area(ST_Split(surface.geom, limite_a.geom)) from surface, limite_a where ...
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1answer
991 views

PostgreSQL : finding all lines intersecting with a polygon

I am totally new in the world of GIS but as a student surveyor I am working on a project using postgreSQL and PostGIS. I have one database with all the roads of my country (lines), and one database ...
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168 views

Help with postgis on mapserver

just set up my mapserver on Ubuntu - all good. Downloaded this tutorial and it works fine: http://download.osgeo.org/mapserver/docs/mapserver-tutorial.zip I've tried adding a PostGIS layer to the ...
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2answers
222 views

How to count points once with overlappying polygons?

All, We're using parcel data (polygon) to count student locations (point) based on parcel type. We're doing this using SQL and the ST_Intersects function. It works great, except the City and County ...
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2answers
696 views

Postgres Log Error

I am using Geoserver + GeoWebCache + Postgres for an application. On the application side there is no bugs but on postgres I am getting this log. Please explain and help me to solve this ...
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2answers
174 views

PostGIS: ST_Clip() throws non-noded intersection between LINESTRING

I have a polygon and a set of rasters. I'm trying to clip raster with polygon. As you see, my rasters is divided into tiles. Any tiles that is contained by the polygon has ST_Overlaps(polygon, ...
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1answer
242 views

using postgis function in pyqgis

I'd use Postgis function in Pyqgis script. This code: qsql="(select gid, id, St_Buffer(the_geom,200) as geom from archi)" uri = QgsDataSourceURI() uri.setConnection("ip", "port", "x", "x", "x") ...
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270 views

PyQGIS Dialog Plugin not resetting

I have written a PostGIS search plugin that works pretty well, except two things that I just cannot figure out a solution 1) When the dialog closes and then is reopened the previous query is still in ...
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3answers
216 views

Geometry vs geography for line-to-polygon intersection

I have two WGS84 NAD83 shapefiles, one polygonal, the other containing lines: Geometry: Polygon Feature Count: 1294 Extent: (-79.761059, 44.991143) - (-57.105486, 62.582865) Layer SRS WKT: ...
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3answers
3k views

PostGIS: parse geometry wkb with OGR

I'm trying to pull a LineString geometry out of PostGIS and parse it with OGR (python bindinds). from osgeo import ogr import psycopg2 connection = psycopg2.connect("...") cursor = ...
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2answers
237 views

How to obtain timestamp and user id from .osm file in PostGIS enabled Postgres database

At present, osm2pgsql seems to ignore the timestamp and user id of the elements, a serious drawback for some applications. According to a bug report this is not solved by the addition of the ...
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384 views

How do I catch PostGIS/PostgreSQL RAISE messages in QGIS?

I have a trigger set up in PostGIS/PostgreSQL which will show a RAISE WARNING when an inserted or updated polygon is within a certain distance of some predefined planning constraints. I want this ...
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2answers
345 views

Switch coordinates in linestring

I made a silly mistake: when creating linestrings in my PostGis database i inverted the lon and lat values. Which isn't a problem for postgis itself, but for my visualization and intersections. ;) Of ...
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260 views

django---error in displaying data and displaying it on the map

. i am trying to display a feature queried from postgis. . i also designed a user input field to enter the id of the desired feature to be displayed. . i have already queried the attributes first ...
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1answer
182 views

PostGIS: ST_Clip() raster in SRID:32617 with a polygon

I'm trying to ST_Clip() raster in `SRID:32617' with a polygon. What I did ST_Transform(polygon, 32617): It fails, couldn't project point() exceeded limit (-14) ST_Transform(rast, 4326, ...
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1answer
660 views

PostGIS ST_Intersection of polygons can return lines

When clipping the polygons of one table with polygons in another, ST_Intersection can return a set of results that can be handled with ST_Dump. The returned multiple geometries are not necessarily ...
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2answers
790 views

How to get the geometry type of an empty PostGIS table?

I have a web application that needs to know the geometry type of a PostGIS table's geom field before inserting rows into it. I use the following query to determine the geometry type of the geom ...
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0answers
48 views

Differences between PostGis and SpatiaLite [duplicate]

I am working on spatial data where there is quite a lot of data (mainy data from GBIF for people who know it). It is not so complicated analyses (I am not Gis Expert!). I am currently working with ...
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1answer
315 views

Cache geodjango query with bounding box filter

Im using geodjango (postgis) to retrieve points contained inside a bounding box (made by leafletjs), it works so nice, but now I want to cache this query. A tipical query is one like this: ...
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29 views

PostGIS: ST_Transform() couldn't project point (lon, lat) exceeded the limits [duplicate]

I'm trying to clip rasters with a polygon. Here's my query: SELECT ST_Union(ST_Clip(landsat8.rast, ST_Transform(ST_GeomFromText('POLYGON((105.78873 21.38659, 106.49185 21.38659, 105.78873 20.71758, ...
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1answer
55 views

Rendering PyQGIS objects in MapCanvas

I'm quite new to PyQGIS and have what is probably a pretty basic question, but I haven't been able to pick it up from the documentation. I have a QgsVectorLayer object from a PostGIS server, and I ...
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1answer
55 views

Query to create polygone from lines that touches in POSTGIS

I am trying to create polygons from a line layer with a spatial query in postgis the probleme is i dont have a lot of information on the lines only id of each line and geometry thanks for your help
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1answer
344 views

PostGIS ST_Within returns zero data

I am using PostgreSQL 9.3.3 & PostGIS 2.1.1 and I have a table Entries which has a column called "latlng" of geographic type (this column stores entry's latitude and longitude coordinates). I am ...
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267 views

pgrouting unexpected output

Thats my ways.shp file. I loaded this to PostgreSQL DB using PostGIS shape file loader. I ran pgr_anlayzeGraph() on it and found it had a lot of isolated segments. Next I ran pgr_nodeNetwork() to ...