Abstract. In this paper we present a new approach for studying aggregations in the context of database query languages. Starting from a broad de nition of aggregate function, we ad...
In data integration systems, queries posed to a mediator need to be translated into a sequence of queries to the underlying data sources. In a heterogeneous environment, with sour...
Ramana Yerneni, Chen Li, Jeffrey D. Ullman, Hector...
Abstract. In this paper we consider databases representing information about moving objects (e.g. vehicles), particularly their location. We address the problems of updating and qu...
Ouri Wolfson, Liqin Jiang, A. Prasad Sistla, Sam C...
A large number of database index structures have been proposed over the last two decades, and little consensus has emerged regarding their relative e ectiveness. In order to empir...
Joseph M. Hellerstein, Lisa Hellerstein, George Ko...
The vast number of design options in replicated databases requires efficient analytical performance evaluations so that the considerable overhead of simulations or measurements can...
Electronic newsgroups are one of the primary means for the dissemination, exchange and sharing of information. We argue that the current newsgroup model is unsatisfactory, especial...
Federated transaction management (also known as multidatabase transaction management in the literature) is needed to ensure the consistency of data that is distributed across mult...