Migration To Open Source Database Systems
Channel: Andrea Ross
Date: 2013-09-28

Changing data distribution from one relational database system to another should be an easy task. SQL is a standardized database language and concepts concerning spatial data is much the same through OGC standards. Still, some tasks has to be done in a slightly different manner. The Danish Geodata Agency decided to explore changing a major part of its data distribution from a commercial Oracle Spatial database to an open source PostGres/PostGIS database. A pilot project was set up to evaluate PostGIS as a productive distribution database accessed by a lot of users through open source services. Experiences were positive and the pilot system was upsized to a full scale production system. The database setup is designed to facilitate sufficient performance and ensure constantly running service. Databases and services are replicated and a master-slave relation is established between the databases to ensure immediate copying when new data are transferred from the authoritative database. A special challenge was the change-over from the old system to the new one while services were still running. New data are copied on a daily basis. Old and new system were run in parallel for a short while to be sure that the new system was stable. The change-over has mainly been done by inhouse employees, which were non-specialists in open source products. Documentation and expert service companies are available if help is needed. Experiences are positive. The Danish Geodata Agency decided to explore changing a major part of its data distribution from a commercial Oracle Spatial database to an open source PostGres/PostGIS database. A pilot project was set up to evaluate PostGIS as a productive distribution database accessed by a lot of users through open source services. Experiences were positive and the pilot system was upsized to a full scale production system.