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OGC/WFS
The Open Geospatial Consortium/Web Feature Service is a specification developed by the Open Geospatial Consortium that describes Web Feature Server (WFS) operations. The WFS operations support INSERT, UPDATE, DELETE, QUERY and DISCOVERY of geographic features using HTTP as the distributed computing platform. This document adopts the same concept of a geographic feature as described in the OGC Abstract Specification and interpreted in the Geographic Markup Language (GML) Implementation Specification [2]. That is to say that the state of a geographic feature is described by a set of properties where each property can be thought of as a {name, type, value} tuple. The name, number, and type of each feature property is determined by its type definition. Geographic features are those that may have at least one property that is geometry-valued. This, of course, implies that features can be defined with no geometric properties at all. The geometries of geographic features are restricted to what OGC calls simple geometries. A simple geometry is one for which coordinates are defined in two dimensions and the delineation of a curve is subject to linear interpolation. The traditional 0, 1 and 2-dimensional geometries defined in a 2-dimensional spatial reference system are represented by points, line strings and polygons. In addition, the OGC geometry model allows for geometries that are collections of other geometries - either homogeneous multi-point, multi-line string, and multi-polygon collections or heterogeneous geometry collections. Finally, GML allows features that have complex or aggregate non-geometric properties. The architecture includes: Client Application Any program or process that communicates with a web server using HTTP. The most typical example is a web browser but other types of programs can exist as well. For example, one can imagine a data loader or geodata editor that communicates with an HTTP server. HTTP Server Any program that services HTTP requests. For example, the Apache program is an HTTP server. Web Feature Server A program or module that implements support for transaction and/or query operations on web accessible features OGC Feature Datastore A software system for persistently storing and managing the spatial and non-spatial properties of geographic features. The management system can be a SQL relational database, flat files, an ARCINFO database, an XML based datastore, etc... Visit the Open Geospatial Consortium homepage at http://www.opengeospatial.org/