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

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Incorrectly Projected PostGIS data in TileMill

When I bring PostGIS data in EPSG:900913 into TileMill, my layers end up on other continents. This is my workflow: (1) Save shapefiles in QGIS to EPSG:900913 (2) Import the shapefiles using PostGIS ...
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1answer
1k views

How to find the country in which a point is located?

I have a PostGis database created with osm2pgsql. I am looking for a way to add the country name in which a point is located to the point row. It must work also for countries with enclaves, such as ...
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33 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 ...
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1answer
486 views

What is the maximum number of vertices for polygons & polylines in PostGIS?

What is the maximum number of vertices for polygons and polylines (including multipart) in PostGIS? Thanks
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1answer
864 views

Wrong projection on WFS layer with OSM baselayer [duplicate]

I am trying to add a vector layer with a WFS protocol. var wfs = new OpenLayers.Layer.Vector("WFS", { strategies: [new OpenLayers.Strategy.BBOX({resFactor: 1})], ...
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174 views

Win7 Senior users_Which pgRouting and postGIS versions are stable with postgreSQL8.4?

I'm working on a postgreSQL ,postGIS and pgRouting project on Windows 7 I need to work on a stable version (no time for risks), and I can see that many people are asking the same question many places....
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3k views

Unable to install the PostGIS extension to PostgreSQL on Ubuntu 12.04 LTS

I just installed Linux Ubuntu 12.04 LTS (on a virtual machine). I then successfully installed the PostgreSQL 8.4 database management system. I am now trying to install PostGIS, which is an extension ...
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1answer
1k views

How to install multiple versions of postgres in same os windows 7 64-bit?

I have already installed PostGIS along with opengeosuite and it is the latest version. Now I want to run pgrouting but the latest stable version does not compatible to the latest postgres versions. ...
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827 views

Public PostGIS Server available?

Can anyone point me to a (if possible at all) list of public PostGIS Servers, where one can set up their own database/tables? I would need a PostGIS server on 24h/7d while not having the resources by ...
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510 views

How to install PostGIS 8.4 in windows 7 64 bit parallel to an existing PostGIS 9.2?

PostGIS 9.2 is installed along with OpenGeoSuite using one click setup. But 9.2 dont support pgRouting. So I need to install 8.4. I dont how to include binaries and all. So someone please tell me how ...
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1k views

postgis distance calculation between points with lat, long coordinates

Team, I am new to postgis, but a postgres user for quite a while. I would like to compare the geospatial capabilities between postgresql and mongodb. I have the lat.lon, zip code of US locations; ...
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203 views

Does each road segment need to be digitized into a separate entry for a road network?

I am trying to understand this code in pgRouting for creating topology: CREATE OR REPLACE VIEW road_ext AS SELECT *, startpoint(the_geom), endpoint(the_geom) FROM road; CREATE TABLE node AS ...
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121 views

Identifying Intersections of Geology using PostGIS

I'm having problems identifying intersections on a layer of linework, the lines are representative of contacts and faults (geological rock formations). I am trying to select where there are connected ...
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205 views

What are the rules for digitizing roads for creating a road network?

I want to create shortest route tool using pgRouting. But I digitised roads in a random manner. Shall I need to give a separate row for each road segment?
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547 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 ...
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110 views

not able to view imported .tif file in geoserver

I am using geoserver. I have imported a .tif file using postgis, which has been saved in vector type layer in geoserver. Now, whenever, I preview it, the layer gets automatically downloaded as wms ...
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1answer
205 views

How can I check if a multipolygon can be represented as a simple polygon?

I have a large (30m+ records) spatial data set I have imported into a PostGIS database. I did not expect to find multipolygons in the data set, but it does have a few of them. I'd like to take a ...
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1answer
256 views

How can i select many rows from a table?

I want to create an action that select many rows from PostGIS table to show many lines in QGIS. How can i select many rows from table with python to add these rows in a layer? Thank you
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1answer
899 views

raster2pgsql missing in Opengeo-suite installation

I installed opengeo-suite 3.0.2 on Ubuntu 12.04 and although the stack seems to be working fine, raster2pgsql is no where to be seen! root@mywebsite:/usr/local/lib/postgresql/9.2# locate raster2pgsql ...
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2answers
768 views

Can Geoserver return the raster value of a lat/lon point

I have a GeoTIFF published by Geoserver 2.2 and being used by Leaflet via WMS. How can I get Geoserver to return the raster value at a lat/long point? I'm guessing it has to do with using WCS, but ...
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2answers
897 views

I can't export in QGIS a Shape file to PostGis

When I try export a pipe network shape to postgis i get this error: Problema inserindo feições do arquivo: C:/PP/gvSIG_Projects/Shapes/Abastecimento/QGIS_VATROCOADUTOR.shp Ocorreu um erro no banco ...
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1answer
4k views

How to import QGIS Raster into PostGIS

I have created a IDW heatmap using QGIS 1.8.0 and need to import the raster into PostGIS 2.0.1. QGIS saves the raster layer as a .asc file. How do you import the raster into PostGIS as a Raster? What ...
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2answers
5k views

Which function for creating a POINT in PostGIS?

When defining a Point in PostGIS, when do you decide to use which of the following? ST_SetSRID(ST_MakePoint(lon,lat),4326) ST_SetSRID(ST_Point(long,lat),4326) ST_SetSRID(ST_GeomFromText('POINT(lon ...
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1answer
1k views

Get the lines between all points of a polygon in PostGis : avoid nested loop?

I am trying to get all the lines between the points of a polygon, by writing PostGreSQL functions. I have written the two following functions that do the job fine : the first function to get all the ...
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178 views

Creating polygons for a choropleth map using PostGIS

I have a grid of points, each with a value to it as shown in the image below. The data was retrieved from PostGIS and rendered in Quantum GIS. The final result should be a polygons of a choropleth map ...
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3answers
397 views

What is the easiest one click install method for PostGIS and it's entire dependencies?

For someone new to database servers and their dependencies, what is the easiest assured way of installing PostGIS on a machine with no other software beyond what comes with its operating system? I'd ...
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3answers
5k views

Connnect to PostGIS db using QGIS - when not on localhost

I"m just getting started with PostgreSQL/PostGIS db (v9.2) and I'm wanting to connect to db while not on the localhost using QGIS. I've been able to connect successfully on localhost, however I'm not ...
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2answers
125 views

Is PostGIS doing a full table scan?

I am trying to retrieve all points p that are within polygons c. While building the query, I came across this strange behavior. Question: Why does query 2 takes so long compared to query 1? Is it ...
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2k views

PostGIS Better ST_Intersects Query

I am currently using the following queries to return all features that intersect a large and complex polygon. I initially tried to use a single ST_Intersect query but because the number of features it ...
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1answer
334 views

How can I map data points to OpenStreetMap (OSM) line data?

my goal is to filter measuring points of vehicles by mapping them to streets. So I could filter out all the false data located in fields and rivers and so on. I imported my data into a PostGIS ...
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3k views

PostGIS installation on Ubuntu 10.12 (Amazon Services)

On Ubuntu 10.12 (AMI on Amazon), I use aptitude to install Postgresql and PostGis. On terminal running psql interactive prompt, I type CREATE EXTENSION postgis and ERROR: could not open extension ...
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339 views

pgRouting:how to use reverse_cost?

I add a new column, naming it "reverse_cost", and give it the same data in the shape_leng column. But as I run the shortest path algorithm in pgadmin, I got an error message. here's my sql code ...
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2answers
2k views

Problem loading PostGIS (Postgres) View layer in QGIS

Why is Postgres user XX via command „Add PostGIS Layers“ in QGIS enabled upload only View tables which owns? Or how to achieve it to the user XX via PostGIS can load View table which owns the user YY? ...
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530 views

How to create a new column to store the length of a linestring in postgis?

I am working with pgRouting, following this nice guide:A Beginner’s Guide to pgRouting I am now in this step:Calculating shortest routes, with these codes below SELECT * FROM shortest_path(' SELECT ...
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2answers
3k views

PostGIS: Convert meters to arbitrary spatial reference units?

I'm writing a query that needs to be able to work with data of any SRID. The basic problem is very simple - I get two pieces of information: A point (SRID = 900913) A distance (unit = meters) I [...
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1answer
265 views

Creating the node ids:Is this SQL error related to geometry type?

I loaded a multilinestring layer into PostGIS Manager: and use the SQL query, trying to get the table with the node ids: ALTER TABLE split_4 ADD COLUMN source integer; ALTER TABLE split_4 ADD ...
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1answer
255 views

ST-Links convert Feature Class to DB Table error

I'm using ArcMap with the ST-Links SpatialKit Conversion tool to convert a Feature Class to a DB Table. But I'm getting an error: ERROR: 42601: type modifier is not allowed for type "geometry". I can'...
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1k views

From a trajectory of GPS points to a multiline segment

Given a trajectory as a sequence of GPS points I would like to create a smooth linestring representing a path where a car drove. The data is stored in postgresql: the input trajectory in a table, ...
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1answer
646 views

Aggregate points with same values to polygons

I have a shapefile with 2M measurement points (each measurement point has a resolution of a 1/10). How can I aggregate points around each other if and create polygons out of it? They do not have to ...
2
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1answer
170 views

assign_vertex_id:problems when creating the node ids

Before using pgrouting, I have to create the node ids. I loaded my polyline layer into PostGIS Manager: I type this in SQL query: select assign_vertex_id('split_4', 800, 'geom', 'gid') But as ...
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1answer
797 views

Accurate and fast nearest neighbour, which distance function should I use and how to it speed up? [duplicate]

I am solving the following problem: I have a map with many points in it and I need to find the nearest point to given location. Each point carries information about it's latitude and longitude. This ...
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4answers
4k views

“Geometry type does not exist” on a Postgis installation on Fedora 18

Just installed PostgreSql and PostGIS over a brand new installation of Fedora 18. I did it this way: sudo yum install postgresql postgresql-server postgrsql-contrib postgresql-devel pgadmin3 Once ...
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1answer
351 views

SQL Command to convert pgRouting result to GeoJSON

My goal is to produce a Web UI for pgRouting using this tutorial. I have already imported my data from an OSM pBF to PostGIS using osm2po. Using the pgRoutingLayer plugin for QGIS, I was able to ...
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1answer
731 views

Force dimensionality with shp2pgsql

After invoking: shp2pgsql -W "latin1" theshape.shp > thesql.sql My console responds with: Shapefile type: PolygonZ Postgis type: MULTIPOLYGON[2] Note the shapefile type is PolygonZ. The result ...
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1answer
119 views

Schema for offline map editing and pass to production environment

I'm working with QuantumGIs and PostgreSQL/Postgis. So when I edit the layers, the changes are reflected on the DB. The thing is I want to do some "offline" editing before committing the changes to ...
3
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1answer
282 views

Get Multiple Shortest Path using PgRouting in One Query

I am trying to get multiple shortest path using A* Algorithm available in PgRouting. I referred Solution given by UnderDark ( Link of the Stakoverflow Post ) . But it is not giving me proper Output. ...
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1answer
63 views

What is the best way to construct a SQL query that returns the block name for each bus point as it travels?

I have two datasets in postgres; 1) a bunch of points that represent bus locations 2) city block polygons. Each bus has a unique ID and each block polygon has a field that has the block name in it. ...
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1answer
118 views

OpenLayers - possible to display detailed GIS data?

I have an OpenLayers app to plot point features, but need to read in a very detailed multipolygon vector layer to plot an accurate location. I'm currently loading the polygon layer via TinyOWS. I've ...
2
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1answer
95 views

Recommended way for changing value in PostGIS using GeoServer

I have a map being rendered from PostGIS using GeoServer. I frequently make some edits to the map and update the new value by directly connecting to the PostGIS database and then making the changes ...
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1answer
442 views

Difference in raster size using raster2pgsql

I use the PostGIS-build-in raster2pgsql to load SAGA-raster into the db. I tried to grid them into 100x100-tiles, just as seen in the code: /usr/lib/postgresql/9.2/bin/raster2pgsql -s 32632 -a -F -...