DEEGREE3 WFS: ADVANCED SUPPORT FOR COMPLEX APPLICATION SCHEMAS
The deegree WFS looks back on more than 5 years of supporting complex GML application schemas. The most notable characteristic of such schemas are feature types that define feature-valued properties (features nested or referenced in features). Examples of successfully implemented schemas with the deegree WFS include GeoSciML (a GML application language for geosciences), XPlanGML (German standard for town, urban and regional planning) and the INSPIRE Data Specification on Addresses (unified data model for addresses in Europe).
The deegree3 WFS was designed based on these experiences. While the deegree2 WFS was already powerful, but complex in configuration, the deegree3 WFS introduces a new design and a drastically simplified configuration concept. Additionally, the new implementation offers much better scalability and advanced support for complex application schemas.
The presentation will introduce and demonstrate the features of the deegree3 WFS:
The deegree3 WFS is a thorough implementation of the OGC standards WFS 1.0.0 and 1.1.0 (2.0.0 is planned), is fully transactional (even for complex features), XLink-capable and supports different flavours of GML (2, 3.0, 3.1 and 3.2). Queries may use complex filter expressions that take advantage of the full power of XPath 1.0. The advanced feature model of deegree3 enables to use feature type hierarchies, nested features and even custom property types. As deegree3 contains an ISO 19107-compliant geometry model, the WFS can natively handle complex geometries such as non-linear curves. XML-streaming enables the WFS to serve gigabyte-sized GML datasets with a minimal memory footprint.
Markus Schneider - lat/lon GmbH