Pr é cis: The Essence of a Query Answer

Wide spread use of database systems in modern society has brought the need to provide inexperienced users with the ability to easily search a database with no specific knowledge of a query language. Several recent research efforts have focused on supporting keyword-based searches over relational databases. This paper presents an alternative proposal and introduces the idea of précis queries. These are free-form queries whose answer (a précis) is a synthesis of results, containing not only information directly related to the query selections but also information implicitly related to them in various ways. Our approach to précis queries includes two additional novelties: (a) queries do not generate individual relations but entire multi-relation databases; and (b) query results are personalized to user-specific and/or domain requirements. We develop a framework and system architecture for supporting such queries in the context of a relational database system and describe algorithms that implement the required functionality. Finally, we present a set of experimental results that evaluate the proposed algorithms and show the potential of this work.