Data integration is the problem of combining data residing at different sources, and
providing the user with a unified view of these data. The problem of designing data …

The query optimizer is one of the most important components of a database system. Most
commercial query optimizers today are based on a dynamic-programming algorithm, as …

One of the basic problems in the development of techniques for the semantic web is the
integration of ontologies. Indeed, the web is constituted by a variety of information sources …

Data integration systems provide access to a set of heterogeneous, autonomous data
sources through a so-called global schema. There are basically two approaches for …

We address the problem of query rewriting for TSL, a language for querying semistructured
data. We develop and present an algorithm that, given a semistructured query q and a set of …

Data integration systems provide access to a set of heterogeneous, autonomous data
sources through a so-called global schema. There are basically two approaches for …

Most of new databases are no more built from scratch, but re-use existing data from several
autonomous data stores. To facilitate application development, the data to be re-used …

The problems of Data Integration/Exchange (DE) and Ontology Based Data Access (OBDA)
have been extensively studied across different communities. The underlying problem is …

Abstract Information integration is the problem of combining the data residing at different,
heterogeneous sources, and providing the user with a unified view of these data, called …

The foundational homomorphism techniques introduced by Chandra and Merlin for testing
containment of conjunctive queries have recently attracted renewed interest due to their …