A foundation for representing and querying moving objects

摘要: Spatio-temporal databases deal with geometries changing over time. The goal of our work is to provide a DBMS data model and query language capable handling such time-dependent geometries, including those continuously that describe moving objects. Two fundamental abstractions are point region, describing objects for which only the position, or position extent, respectively, interest. We propose present as attribute types suitable operations, is, an abstract type extension language. This paper presents design system types. It turns out besides main interest, relatively large number auxiliary needed. For example, one needs line represent projection into plane, “moving real” distance two points. then becomes crucial achieve (i) orthogonality in system, i.e., constructors can be applied unifomly; (ii) genericity consistency operations range many possible behave consistently; (iii) closure between structure nontemporal related temporal Satisfying these leads simple expressive may integrated yield powerful querying spatio-temporal data, formally defines offers detailed insight considerations went design, exemplifies use using SQL. precise conceptually clean foundation implementing extension.