1. Tema 1: Applicazioni per basi di dati su Internet e Intranet Use of ontologies and extensional inter-schema properties for integration D. Beneventano, S. Bergamaschi, F. Guerra, S. Castano, M. Vincini Rapporto D1.R2 30 Aprile 2001

2. 2 Abstract We detail and extend the method described in D1.R1  we take into account the extensional intra and inter-schema properties  we show as these properties influence the integration process  complete syntax and semantics of the OCDL Description Logic  theoretical foundations of the techniques to discover affinity

3. 3 Extensional relationships in ODL I 3 : the instances of C1 are the same of C2 : the instances C1 are a subset of the instances of C2 extensional relationships constrain the structure of the two classes: C1 NText C2 is equivalent to an ISA relationship.

4. 4 Common Thesaurus schema-derived extensional relationships  ISA relationship in object source schemas  foreign keys in relational source schemas interface Restaurant ( FD source key r_code... interface Bistro (FD source key r_code foreign_key(r_code) references Restaurant,...

5. 5 Common Thesaurus inferred extensional relationships rule Rule2 forall X in FD.Restaurant : (X.pers_id in FD.Person) then X in ED.Fast-Food; interface Bistro (FD source foreign_key(pers_id) references Person

6. 6 Clustering  extensional relationshipd force the inclusion of a class in a cluster. … classes that have an extensional relationship with at least one class in the cluster and not yet included in i), are forced to belong to the cluster anyway, the integrated global class is representative of all possible semantically related source classes.

7. 7 Phase 2  optimal query reformulation, by detecting extensionally overlapping classes  object fusion (to identify instances of the same object and fuse them) by defining join criteria among classes Exploiting extensional knowledge in query processing activities D1.R8 : “Functional specification of the Query Manager” (MO)