DEDALE, A Spatial Constraint Database

This paper presents a rst prototype of a constraint database for spatial information, dedale. Implemented on top of the O2 DBMS, data is stored in an object-oriented framework, with spatial data represented using linear constraints over a dense domain. The query language is the standard OQL, with special functions for constraint solving and geometric operations. A simple geographical application from the French Institute for Geography, IGN, is running on dedale. The data initially in vector mode was loaded into the database after a translation to constraint representation. Although it is too early to speak of performance since not all operations have been optimized yet, our experience with dedale demonstrates already the advantages of the constraint approach for spatial manipulation.