Research in modeling and querying spatial data has primarily focused on traditional "crisp" spatial objects with exact location and spatial extent. More recent work, how...
Ontology, an explicit specification of shared conceptualization, has been increasingly used to define formal data semantics and improve data reusability and interoperability in en...
We propose XRPC, a minimal XQuery extension that enables distributed yet efficient querying of heterogeneous XQuery data sources. XRPC enhances the existing concept of XQuery func...
We propose a novel string search algorithm for data stored once and read many times. Our search method combines the sublinear traversal of the record (as in Boyer Moore or Knuth-M...
Witold Litwin, Riad Mokadem, Philippe Rigaux, Thom...
When integrating data from heterogeneous sources, it is often necessary to transform both the schemas and the data from the underlying sources in order to present the integrated d...
Many aspects of the data integration problem have been considered in the literature: how to match schemas across different data sources, how to decide when different records refer...
An optimization query asks for one or more data objects that maximize or minimize some function over the data set. We propose a general class of queries, model-based optimization ...
Incompleteness due to missing attribute values (aka "null values") is very common in autonomous web databases, on which user accesses are usually supported through media...