Christian S. Jensen

TL;DR: This work describes several optimizations that can make selectivity estimation highly efficient, and presents a complete implementation inside PostgreSQL's query optimizer that does not make the independence assumptions.

TL;DR: This work presents indexing, update, and query processing techniques that are capable of providing the top-k terms seen in posts in a user-specified spatio-temporal range and extends existing frequent item counting techniques to maintain exact counts rather than approximations.

TL;DR: This paper investigates several aspects of the resulting generalized temporal relations, including the ability to query a predecessor relation from a successor relation, and the presented framework for generalization and specialization allows one to precisely characterize and compare temporal relations and the application systems in which they are embedded.

TL;DR: In this article, a general framework is proposed to solve the problem of annotating all edges in a road network with travel cost based weights from a set of trips in the network that cover only a small fraction of the edges, each with an associated ground-truth travel cost.

TL;DR: It is demonstrated that an efficient inference method can be seamlessly integrated into existing index structures designed for moving objects, thus improving the meaningfulness of range and nearest neighbor query results in highly dynamic and uncertain environments.