A Methodology to Define External Schemas in ODMG Databases

The ODMG standard is a proposal to solve one of the main drawbacks of object-oriented databases (OODBs): the lack of a standard for object definition and management. Nevertheless, this standard does not offer a solution for another lack of OODBs, related to the definition of external schemas. In this work, a methodology to define external schemas in ODMG databases is put forward. This methodology proposes a solution for the tasks involved—specification, closure and generation of external schemas—introducing also an extension of ODMG metadata to enable the definition of external schemas in ODMG databases.