The Institut Géographique National (IGN) is the national mapping agency for France, with 1800 employees and a mandate to collect, integrate, manage and distribute reference geographical information for the whole country.
For many years, IGN has managed the national spatial data using the GeoConcept desktop GIS system. As with other desktop GIS systems, using GeoConcept required that the data be broken up into map tiles for management.
IGN began exploring storing their data in a seamless database for the entire country around 2002. They benchmarked several technologies, including Oracle, DB2 and PostGIS/PostgreSQL, looking for a product that met a number of requirements:
The benchmarking tests showed PostgreSQL/PostGIS with similar performance to the proprietary alternatives.
Frank Fuchs is a project manager at IGN, and was part of the team that selected PostGIS. “Since PostgreSQL and PostGIS are free and open source software, we could use them quietly in a prototype. On the other hand, if we used a commercial DBMS, we could later have a problem in a call for tenders”, said Fuchs. “And also, the low price [of PostGIS] also was a good point.”
Fuchs’ project team has integrated PostGIS into the data management system for the French “BDUni” database — a 3D national integrated database containing roads, rails, hydrography, vegetation, buildings, administrative boundaries and more. They defined a new process and new tools for managing all the BDUni data in a seamless national database, fitting the new data store into the existing tools familiar to the IGN field staff. The team settled on PostGIS as the backend database, and retained GeoConcept as the editing environment for updating data. The GeoConcept software was modified to add new tools for checking data into and out of the central database:
A data loader that takes data from the existing GeoConcept flat file archive and loads it into the PostGIS database. This is used once only, when a file is moved into the new management system.
A data extractor that pulls a specific working unit of data out of the database and into GeoConcept for editing. Working units are allowed to overlap, and several updaters can extract the same feature simultaneously. Overlapping the working units removes the old filed-based problem of edge matching.
A data synchronizer that pushes updates from the client to the database, and pulls changes in the database down to the client. If two people have updated the same feature, then a conflict is raised, and the operator has to choose how to resolve it.
By using the full GeoConcept GIS as an editing environment, the new system allows researchers to work fully disconnected in the field, updating the database as necessary when they have connectivity to the main IGN network. Field researchers do not have to learn a new GIS system for editing the data, as they are already familiar with GeoConcept. The extraction and synchronization tools make heavy use of PostgreSQL’s transactional system, to ensure that the data integrity is not violated in cases of unexpected network failure or disconnection in the middle of a synchronization.
As of October, 2006, the BDUni system is being used by 40 field researchers in 6 different cities in France. Just over 1/4 of France has been loaded into the database so far, about 30 million features. The first features were loaded in July of 2006. By the end of 2006, 130 field researchers are expected to be using the system. In keeping with the requirement for high reliability and data integrity, the system also includes a redundant backup server, which is synchronized with the main server several times a day.
Having completed this project, Fuchs has this advice for other managers, “Remember that databases are very powerful tools, and transactions are a key feature. PostGIS brings these tools to the GIS community very efficiently.”
As a software engineer at the Howard Hughes Medical Institute, I work on a collaborative neuron reconstruction and analysis software called CATMAID 1 (screenshot: 3), which is used for neuroscience research. We use PostGIS to represent neurons in a 3D space.
They consist of 3D points that reference their parent nodes or are the root [=soma of neuron] if they have no parent). Together with synapses, point clouds and TIN meshes for modeling compartments in a dataset, they model the spatial aspects of our neuroscience world. Users create those neuron reconstructions manually in a collaborative fashion plus segmentation programs can be used as additional data source. Using its spatial indices, PostGIS helps us to quickly query neurons in a particular field of view. The space of a single project contains sometimes 100s of millions of interconnected individual points. We also do bounding box intersection queries between neurons and compartment meshes, which then refine in the front-end by doing more precise intersection tests.
This software is used by quite a few research labs and as far as I know they all do their own hosting with a dedicated server and this is what we do as well. The reason being mainly that wth larger datasets, we benefit from machines with a lot of RAM (>256G), fast SSD/NVMe drives and many CPUs as well as fast local data access for e.g. image data.
Thanks so much for making PostGIS work well in non-GIS contexts too—-it makes my life much easier!
Vanguard Appraisals is new to the GIS world. In fact, we aren’t really in the GIS world; we just kind of brush up against it. We do mass property appraisal for entire county and city jurisdictions, and we develop software to collect, price and maintain values. We also host assessment data online so that homeowners can search and find property information much simpler from the comfort of their own home. Our software and websites are used in 7 states (IA, IL, MN, MO, NE, ND, SD).
Nautilytics is a small data visualization and GIS startup based out of Boston, MA. We use PostGIS and PostgreSQL, among other open-source tools to build powerful web applications for US government organizations, public, and private sector companies.