MOVING FROM ORACLE/ARCGIS TO POSTGRESQL/POSTGIS
The Centre for Topographic Information (CTI) is part of the Mapping information Branch of the Earth Science Sector, under Natural Resources Canada. Considered a centre of excellence in geomatics, the Centre meets the Canadians’ needs in terms of digital topographic data.
The Centre’s mandate is to disseminate a variety of digital topographic data through the GeoGratis and GeoBase portals. It is also responsible for creating and maintaining the Digital Topographic Data found on GeoBase. This database contains the information found on topographical maps (roads and railways, rivers and lakes, altimetry, urban zones, buildings, wooded zones, etc.). This topographical information covers all of Canada’s territory.
To achieve his mandate, the CTI works in partnership with the provinces and Territories. Each group is free to choose the system it prefers to produce the Country territorial representation. However, at the end, everyone must deliver their spatial data as 1/50 000 National Topographic System (NTS) tiles to the main repository which is based on Oracle/ArcGIS technologies.
Recently, the CTI data management team has decided to prototype the main geospatial database (GDB) delivery system using open source softwares. The database we have chosen is PostGresql/Postgis. The data model gathers a little bit more than a hundred feature tables and uses around 50 Gb of disk space. The business logic is executed on a Python XML RPC transaction server that handles delivery request of NTS tiles and perform the data transfer to the main repository in a secure way.
This presentation will give you an overview of the GDB data management system and the changes made during the prototyping work to allow a good understanding of what could affect the assessment. Finally, the two implementations will be compared based on different criteria such as technology complexity, performances and cost.
Yves Choquette - Centre for Topographic Information