| Abstract [eng] |
In this work the problem of integration and compatibility of relational and object schemas is investigated. Nowadays object-oriented programming languages are the most popular, but data that has to be manipulated is usually stored in relational databases. It is relevant to map structures that are used in programming languages to relational structures. Data is usually stored in several repositories in enterprise information systems, so there is the need to integrate them. Federated databases are used for this purpose, and they have canonical data model. Semantically poor canonical data model, which consists of attributes and constraints (functional, join and subset dependencies), is proposed. Algorithms are given for transforming relational and object schemas to canonical schema, integrating canonical schemas, transforming canonical schema to structural types (using modified synthesis algorithm) and OWL. Proposed algorithms give unambiguous result and can be partially automated. Modified synthesis algorithm gives better results than standard algorithm as it takes join dependencies into account. The algorithms can be used to restore conceptual schema and object structures from relational schema as well as to integrate schemas. |
