Logic-based integration of query answering and knowledge discovery

Abstract

There is currently great interest in integrating knowledge discovery research into mainstream database systems. Such an enterprise isnontrivial because knowledge discovery and database systems are rooted in different paradigms, therefore foundational work needs to be carriedout and a candidate unified syntax and semantics needs to be proposed. Elsewhere we have indeed carried out such foundational work and used itto propose a unified syntax and semantics for integrating query processing and knowledge discovery. We refer to the resulting class of databasesystems as combined inference database systems (CIDS), since they are a class of logic-based databases and the integration is anchored by aview of query answering as deductive inference and of knowledge discovery as inductive inference. The most important novel capability ofCIDS is that of evaluating expressions which seamlessly compose query answering and knowledge discovery steps. This gives rise to increasedflexibility, usability and expressiveness in user interactions with database systems, insofar as many relevant and challenging kinds of informationneeds can be catered for by CIDS that would be cumbersome to cater for by gluing together existing, state-of-the-art (but, syntactically andsemantically, heterogeneous) components. In this paper, we provide an overview of CIDS, then we introduce two motivating applications, weshow how CIDS elegantly support such challenging application needs, and we contrast our work with other attempts at integrating knowledgediscovery and databases technology.