In recent years wavelets were shown to be effective data synopses. We are concerned with the problem of finding efficiently wavelet synopses for massive data sets, in situations...
We give two sufficient conditions on XPath like languages for having first order expressivity, meaning that every first order definable set of paths in an ordered node-labeled t...
What does a data stream mean? Much of the extensive work on query operators and query processing for data streams has proceeded without the benefit of an answer to this question. ...
David Maier, Jin Li, Peter A. Tucker, Kristin Tuft...
Abstract. In this paper, we consider whether traditional index structures are effective in processing unstable nearest neighbors workloads. It is known that under broad conditions...
Abstract. A classical problem in query optimization is to find the optimal ordering of a set of possibly correlated selections. We provide an ion of this problem as a generalizati...
We propose and investigate from the algorithmic standpoint a novel form of fuzzy query called approximately dominating representatives or ADRs. The ADRs of a multidimensional point...
Abstract. We survey work on statically type checking XML transformations, covering a wide range of notations and ambitions. The concept of type may vary from idealizations of DTD t...
The existence of a language expressing precisely the PTIME queries on arbitrary structures remains the central open problem in the theory of database query languages. As it turns o...
The traditional way of representing motion in 3D space-time uses a trajectory, i.e. a sequence of (x,y,t) points. Such a trajectory may be produced by periodic sampling of a Global...