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

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Postgres/PostGIS Spatial Query Performance Problem

I have a query in Postgres/PostGIS that I am a bit confused about. The spatial intersection happens very fast, ~ 2 seconds for 10,000, but the update takes > 15 seconds for the same number of points. ...
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2answers
2k views

How to get accurate mile markers from DOT ShapeFile?

I'm having trouble getting accurate mile markers through route traversal using PostGIS. Based on the discussion in Geocode from mile marker/milepost to latitude/longitude?, I downloaded Texas ...
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5answers
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How to create regular point grid inside a polygon in Postgis?

How to create, inside a polygon, a regular grid of point spaced x,y in postgis? Like the example:
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3answers
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Is there a CASE Tool for modelling spatial databases?

Does anyone knows if there is a CASE Tool that would be possible for modelling spatial tables? I need to create a model and export it to SQL or a database directly. I´m using PostGIS. Thanks in ...
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6answers
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PostGIS: Select features that do NOT intersect

This seems to me like such a simple question (and it probably is) yet I cannot seem to find an example that gives me the answer. Using PostGIS, I just want to select points that fall outside of ...
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2answers
280 views

Are there asset management systems for PostGIS?

Are there asset management systems that use PostGIS for asset storage?
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4answers
964 views

Can GeoNetwork store metadata for a PostGIS table?

Can GeoNetwork be used to store Metadata for a PostGIS table? Or is it only for WMS/WFS services? If it can be used to create a store metadata for a PostGIS table, how is it done? I can't seem to ...
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2answers
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Querying data linked to a postGIS database

My project is coming along nicely! A brief background on my project. I have a world map that is colored to show the country of origin of the students at a college. Each color represents the ...
7
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1answer
456 views

How to use simplify()

i have my Vector Data saved in a PostgreSQL PostGIS enabled Database. The Data im displaying is very detailed, i want to simplify it through the simplify() method of Postgis. I duplicated one of my ...
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3answers
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Retrieve polygon smallest MBR

I have a postgis table containing polygons. I want to transform my polygons to 4 points polygons : retrieve the smallest MBR. Here comes an illustration of what I want : My original polygon is ...
7
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1answer
2k views

How do I get a country border data set into my geography column?

I have a PostGis database with a multipolygon geography (as opposed to geometry) column. I'd like to fill it with the country border data available from ...
6
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1answer
318 views

Postgres/postgis cursors

I have a road network with StreetName and min/max address ranges for each segment (ie- StreetName = 'Main St', Min = 100, Max = 199). I also have individual address points with similar information ...
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3answers
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Can you set the PostGIS SRID when creating a Feature class through ArcCatalog?

I have ArcSDE installed in a Postgresql database and I am using PostGIS geometry. I'm not a DB minded person so feel free to let me know if my process is not right. I create my feature class in ...
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1answer
630 views

ArcGIS Flex Polygon to PostGIS Polygon

ArcGIS supports building polygons within the flex component that contain self-intersecting rings, as well as rings that touch at multiple points (breaking the "arbitrary" rules here: ...
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6answers
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Dealing with data that spreads across UTM Zones?

I have data that spreads across two UTM Zones GDA/MGA94 UTM Zone 55 and 56. I have layers such as a cadastre, roads, pipelines etc where I want to store measurements like lengths and areas in metres ...
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4answers
4k views

Generalisation Strategies for Building Outlines

I have a dataset of building footprints vectorised from a raster dataset. The dataset is currently just a vector representation of the raster data. I would like a polygon dataset that only has ...
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1answer
310 views

GIS project advice

Hello: I have the following: Shapefile of the world with the boundaries of each country Successfully imported shapefile into PostGIS database Can display map of the world in a browser via ...
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3answers
1k views

How to populate an undirected graph from PostGIS?

This question is more related to resources that I might not have identified yet, although I've been searching the web for a while. In the project I'm working at the moment I need to run a ...
20
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4answers
3k views

Would PostGIS offer an advantage over MySQL for a produce farm application?

I have a web app that stores the locations of farms in West Michigan. You can search for a product (e.g. "broccoli") and it will show you all the farms that grow that product. Right now I'm using ...
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1answer
463 views

Is QGIS compatible with PostgreSQL 8.4 Advanced enterprise DB with Oracle compatibility?

Sorry for such a long question. We are trialling EnterpriseDB Postgres Plus Advanced Server 8.4 with Oracle compatibility and PostGIS 1.5.1. I can create a connection to the database in qgis and the ...
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8answers
8k views

Getting started with PostGIS?

I have been reading a lot about PostGIS, but I am struggling to find a good beginner's guide. Which tutorials/books do you recommend?
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6answers
856 views

PostGIS: Assign ID of point in layer A to closest point in Layer B

This should have been an obvious precursor (that I didn't ask) to my other question: PostGIS function to create spider diagrams? If I do not know the relationship between a point in layer A (stores) ...
4
votes
1answer
401 views

Remove ArcSDE repository and associated files from PostGresql DB

A bit of background first. I have a PostGres DB with PostGIS, I also have ArcSDE installed in this DB and all feature classes created through ArcSDE are using the PG_Geometry. Everything works well! ...
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3answers
2k views

How to create spider diagrams (hub lines) in PostGIS?

I'm rather new to PostGIS but I have done a lot of reading. One thing that I have been searching for is a function that allows users to create a "spider diagram" (also called "desire lines" or "hub ...
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1answer
855 views

How do I add an offset to a lat/lon to get a new point using PostGIS

Using PostGIS I have a lat/lon point and want to add an east/west and north/south offset in metres to get a new point. Is that possible?
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4answers
864 views

Looking for a basic PostGIS viewer to use as basis for own application

I'm looking for a rather basic PostGIS viewer. It should be possible to pan, zoom and retrieve coordinate information on mouse click. No need to support coordinate transformations. It should introduce ...
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3answers
496 views

PostGIS + ArcSDE mixed environment

I'm trying out a mixed environment here at work with PostGIS and ArcSDE together. I'm having some problems creating feature classes with custom SRIDs. I imagined that all that I needed to do was ...
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2answers
2k views

What coordinate system should be used to store geography data for celestial coordinates?

I am doing an astronomy project. I want to have the information about our images stored in a spatially enabled database. This, I would think, should be a very easy special case for GIS functions ...
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1answer
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Add a polygon to PostGis from Google Maps

i have some experience with Google maps api, I have an app and currently calculate nearest points to locations via distance functions (great circle) and having a lot of waypoints on MySQL. I want to ...
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2answers
981 views

GeoServer GetLegendGraphic request ServiceException

I have a layer in GeoServer which is stored in a PostGIS database. The geometrytype of the layer is GEOMETRY and now the table only contains LINESTRING. But I what to add points and polygons to the ...
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2answers
2k views

Moving a PostGIS Installation

I have a simple question: I have a postGIS installation running on an old computer that I'd like to move. I spent a bunch of time playing with pg_dump and pg_dumpall without success. It seems the ...
2
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1answer
662 views

Routing Application in Windows

I am making an routing web application similar to Google Maps 'Get Direction' feature. But because of the limited control and data on GMaps, I decided to use OpenStreetMap instead. This also made me ...
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2answers
2k views

Geoserver Routing with OSM data and PostGIS

Does Geoserver have a routing functionality for the OSM data in PostGIS?
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2answers
562 views

Data entry and manipulation using web pages

I am working on a project where we want to move a database from Microsoft Access to PostGIS, and we want the data entry forms to be web page based rather than forms within the Access database. I am ...
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4answers
12k views

How to get the nearest point on a linestring to a given point?

I've been using PostGIS for a long time now but never had to use the LINESTRING geometry ...! :) Here's what I would like to do : I have a table of linestrings (representing streets of a given city, ...
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2answers
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I want to edit corresponding postgresql data of a vector from openlayers- how to do it?

I want to edit the corresponding text/numeric data type columns of a vector through openlayres, when a user click/mouse over a vector. like, http://dev4.mapgears.com/bdga/bdgaWFS-T.html# any ...
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3answers
3k views

Render vectors from OSM data in POSTGIS database

I'm a newbie when it comes to mapping application. I had successfully loaded my OpenstreetMap data in a Postgresql/PostGIS database. Now my problem is how to render the vector data (the POI's, ways, ...
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5answers
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Problems in installation of PostGIS

I will be installing PostGIS for my project using PostgreSQl (OSM) in Ubuntu 9.04. I had all the requirements prior to the installation (PostgreSQL, Proj4, GEOS). When I unzip the PostGIS tar, then ...
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2answers
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Geodatabase to PostGIS character encoding

Similar to another question I posted previously, I'm trying to import datasets from Esri geodatabases into a PostGIS database directly, and inside the data there are greek letters and symbols that are ...
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2answers
998 views

How does shp2pgsql define schema?

Can anyone explain how it is that the shp2pgsql loader for loading shapefiles into PostGIS goes about defining the schema for a table when importing a shapefile? To further explain, shapefiles are ...
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2answers
2k views

How to convert OSM Data to PostgreSQL for Routing Purposes?

I'm creating a routing application using OpenStreetMap. Currently, my task is to convert the data from an OSM file to PostgreSQL. I read about osm2pgsql, but the problem is it says there that ...
11
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2answers
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How to import esri Personal Geodatabase (.mdb) to PostGIS on Linux

We have esri Personal Geodatabases that we need to import into PostGIS. Ultimately, we'd like to allow people to upload an MDB on a web server, and have it import the layers into PostGIS. On ...
4
votes
1answer
2k views

Using PostGIS with Rails

I'm new to postGIS, and am looking to use a spatial database with my Rails app (specifically, to retrieve points from the database that are within the bounding box of a Google Maps viewport). I posted ...
8
votes
2answers
745 views

Splitting polylines using regions with PostGIS

I was wondering if it is possible to split a polyline on polygon boundaries (regions) in PostGIS, the picture below is of what we have at the moment and showing where I need the polylines split: ...
7
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1answer
1k views

PostGIS 3D in Action

I was wondering if there is a website that showcases Openlayers and PostGIS 3D in Action
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3answers
9k views

Is there a dissolve function in PostGIS other than st_union?

I'm looking for a function to dissolve shared boundaries between polygon features in a table. ST_UNION() almost does what I'm looking for, but it creates a multipolygon from all polygons in the layer ...
4
votes
2answers
850 views

ArcSDE 10 and PostgreSQL 8.3 vs 8.4

We have recently upgraded our ArcSDE 9.3 instance to ArcSDE 10. I was hoping to upgrade postgresql 8.3 to 8.4 at the same time. Although ArcSDE 10 supports 8.4, it turns out that the ArcSDE wizards ...
14
votes
4answers
4k views

How to create one-sided buffers or parallel lines in PostGIS?

I'm looking for a way to create so-called one-sided buffers or parallel lines in PostGIS. Example: 1. buffer, 2. one-side, 3. both-sides I've found some discussion on the mailing list from 2009 and ...
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7answers
9k views

Options for displaying PostGIS vectors in OpenLayers

I am very new to web-mapping, so this question may be a little misguided. I want to have a very simple web interface using OpenLayers (or even Google Maps if that will be easier) which can display a ...
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votes
6answers
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How can I connect to a PostGIS database from ArcCatalog 9.3 via ArcSDE?

I have a problem connecting to my postgis database via ArcSDE in Arc Catalog. When i want to establish connection to my database i get an error: