PostgreSQL is popular open source object-relational database management system used in GIS organizations and the PostGIS is spatial extension for PostgreSQL.
The PostGIS extension adds spatial capabilities to PostgreSQL, for example: measuring areas, surfaces, distances, 3D measurements and geometry data types. OpenCities Map supports these functions to provide spatial analysis and to maintain 2D and 3D data models.
The information in this article can be used to optimize and maintain PostgreSQL database for better usage with OpenCities Map.
Please feel free to have a look at the attached document.I sincerely hope it will encourage you to try this out for yourself.