Due to the increasing necessity and availability of information from different sources, information integration is becoming one of the challenging issues in artificial intelligence and computer science. A successful methodology for information integration is based on Federated Databases (FDB). However, differently form databases (DBs) a completely satisfactory formal treatment of FDB is still missing. The goal of this paper is to fill this gap. Our basic intuition is that an FDB can be formalized by considering each DB of the federation as a context. We argue that this perspective is a promising one, as some of the relevant problems in the area of information integration, such as semantic heterogeneity, can be successfully solved using contexts. In the paper we provide a formal notion of FDB schema, a semantics for such a schema, called Local Models Semantics for FDBs, and a deduction system which formalizes the logical consequence of Local Models Semantics. We show by means of examples that our formalization overcomes the drawbacks of the previous approaches
Formalizing and Reasoning about Constraints in Federated Databases
Serafini, Luciano;Ghidini, Chiara
1997-01-01
Abstract
Due to the increasing necessity and availability of information from different sources, information integration is becoming one of the challenging issues in artificial intelligence and computer science. A successful methodology for information integration is based on Federated Databases (FDB). However, differently form databases (DBs) a completely satisfactory formal treatment of FDB is still missing. The goal of this paper is to fill this gap. Our basic intuition is that an FDB can be formalized by considering each DB of the federation as a context. We argue that this perspective is a promising one, as some of the relevant problems in the area of information integration, such as semantic heterogeneity, can be successfully solved using contexts. In the paper we provide a formal notion of FDB schema, a semantics for such a schema, called Local Models Semantics for FDBs, and a deduction system which formalizes the logical consequence of Local Models Semantics. We show by means of examples that our formalization overcomes the drawbacks of the previous approachesI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
