A Datalog program can be translated into a system of fixpoint equations of relational algebra; this paper studies how such a system can be solved and optimized for a particular qu...
Abstract. A useful ability for search engines is to be able to rank objects with novelty and diversity: the top k documents retrieved should cover possible interpretations of a que...
Linear optimization queries retrieve the top-K tuples in a sliding window of a data stream that maximize/minimize the linearly weighted sums of certain attribute values. To effici...
XKeyword provides efficient keyword proximity queries on large XML graph databases. A query is simply a list of keywords and does not require any schema or query language knowledg...
This paper introduces U-relations, a succinct and purely relational representation system for uncertain databases. U-relations support attribute-level uncertainty using vertical pa...
Lyublena Antova, Thomas Jansen, Christoph Koch, Da...