Towards a unified view of query- and update-driven Inference in deductive databases

When thinking oí deductive databases, most people will probably associate this notion rather closely with problems of query processing: deductive database research is essen­ tially concerned with formalization and implementation oí information retrieval interins of logical inference. This reaction - which seems to come quasi automatically - is prob­ably due to the fact that the majority of papers on deductive database aspects written in the past has been concemed with query processing. Moreover, this issue has been in the center of interest in database research anyway, not only in the deductive context. In a similarly straightforward manner do we associate rules and query answering. We all would probably agree that activating rules is essentially done in order to infer answers to queries: deduction in databases tends to be regarded mainly as query-driven inference