Digital Geography

Colaborative Working in PostGIS

The last days I needed to work with other geoenthusiasts on a PostGIS database. Unfortunately, as you upload a layer from QGIS you will be the owner of the new created table and no one is able to alter it by default. Here I show you, how to change this using some “trigger functions” and some shared roles.

Short Note: export layers to PostGIS with Processing

When using QGIS along with PostGIS you might want to publish data directly from inside QGIS into your PostGIS database. This is not only convenient as you don’t need to change the software of use but also easier as it only takes a drag and drop in QGIS instead of any commandline/fancytool. Yet it comes with a disadvantage: the number of inserts from QGIS into the db is limited to 200 per transaction. So it will take some time to insert a bigger dataset with 150.000 points or so. So how to overcome this?

Vagrant: Setup and Share your Digital Geo-Lab

In one of my last posts I described the installation of a git server to improve collaborative work in closed environments. But developing solutions can be a pain in the axxxx if you need deal with user/OS dependent issues all the time. So let me introduce you to Vagrant: Vagrant is an open-source software product for building and maintaining portable virtual development environments.

PostgreSQL and PostGIS: A brief introduction

You probably seen this already (maybe on your very own PC as well): A folder with shape files. Well we’re living in the 21st century and I do have and use those folders still. After a talk of Sebastian Meier at Maptime Berlin I was convinced and started to work with a databases instead of folders. So let me show you how to install PostgreSQL along with PostGIS on Ubuntu and Windows, how to get data into it, import OSM data and how to connect it with QGIS/ArcGIS.

Import OSM Data Into A PostGIS Database (The Easy Way)

I often find myself in a situation where I want to work with large areas and datasets of OpenStreetMap data. No matter if you want to use them in a QGIS map or create custom map tiles in Tilemill, with the Overpass API you quickly run into performance issues. Imposm is a great tool to overcome that situation, so you can load OSM extracts (worldfiles in pbf format) with a custom data mapping into a PostGIS enabled PostgreSQL database. The downside: It is hard to set up if you are not a database and system admin guru. This is where…

GIS with javascript – tutorial part 1

An article from Anders. Geodata in javascript GeoJSON is the standard way of storing geodata in JSON, javascripts native data format. The wikipedia article has very clear and telling examples. If you have never heard of GeoJSON, read it. The aim of this article is to show you how to convert your geodata to GeoJSON and some basics in querying the data.

How to use OpenStreetMap, guides for beginners and advanced users on LearnOSM.org

OpenStreetmap is the fastest growing community mapping project of all times. Beside the “normal” map result, what you can use for your daily navigation through cities and countries like Google Maps, OpenStreetMap allows you to get the geodata and use it for your own ideas and projects (with some licence regulations). For many peoples the difficult part is not getting the data but the usage and adoption. Therefore the Humanitarian OpenStreetMap Team created LearnOSM.org.

HeidiSQL vs. pgAdmin III – a small speed-test

HeidiSQL, a free database-client, now supports PostgreSQL/PostGIS in the newest nightly builds. Using HeidiSQL with MySQL was always a pleasure and I often had the feeling that the pgAdmin III client of PostgreSQL is slow and not very user-friendly in some points. Because of this I had to test the difference of performance of these two clients. I don’t want to talk about features and handling because this is on the one hand a matter of taste and on the other hand the support of PostgreSQL is very new in HeidiSQL. Instead, I want to compare some simple SQL-queries in…

OpenSource QGIS + PostGIS installation: “the Windows way”

A short time ago I’ve posted an article on the installation of QGIS in combination with a PostGIS database in the background. As we all know, Windows is mostly used as OS on a PC so this is the Windowized version. This is a short summary that sums up the article of a site called Boston GIS. I’ll show you how to install QGIS version 1.8 (which will be updated in some days) and PostgreSQL with PostGIS extension and show you the first steps in the import of shapefiles and raster data.

OpenSource QGIS + PostGIS installation: “the Ubuntu way”

A lot of you out there are probably working on Windows Systems using ArcGIS and I have to admit that the possibilities with ArcINFO in the background and a proper GDB (GeoDataBase) are really big. But let’s be honest: A lot of your tasks are more or less everyday business, right?! So let us have a look on building a GIS workplace using QGIS 1.8 (which will be updated the big way in some days/weeks) and PostGIS which is a spatial enhancement of PostgreSQL.

cartoDB and Leaflet: creating the table or part one

We have already introduced cartoDB which is a platform for storing, administering and visualizing spatial data. One straight feature of cartoDB is the usage of GeoJSON for exporting their tables. In this tutorial I’ll document a working example on consuming this layer with leaflet. But first we will start with the easy part of creating the table in cartoDB.

Geodatabases: a little insight

Most GIS-users I know don’t use Geodatabases. But as your project may grow, participation and co-working gets more and more usual in your projects and you would like to share not only your results but also your data the usage of geodatabases will be one thing to keep in mind. Normaly each feature or raster is stored in separate files and maybe folders as well. This concept will stay alive in a geodatabase but in a more professional way: ArcGIS gives you the possibility to store your features in a file geodatabase, perosnal geodatabase or an ArcSDE Geodatabase. So what…