Institut für Informatik

Technical Report No. 54, June 1994 - Abstract

Jürgen Frohn, Georg Lausen, Heinz Uphoff
Access to Objects by Path Expressions and Rules

Object oriented databases provide rich structuring capabilities to organize the objects being relevant for a given application. Due to the possible complexity of object structures, path expressions have become accepted as a concise syntactical means to reference objects. Even though known approaches to path expressions provide quite elegant access to objects, there seems to be still a need for more generality. To this end, the rule-language PathLog is introduced. A first contribution of PathLog is to add a second dimension to path expressions in order to increase conciseness. In addition, a path expression can also be used to reference virtual objects. Both enhancements give rise to interesting semantic implications.