A practical approach to access heterogeneous and distributed databases

摘要

A common problem within most large corporations nowadays is the diversity of database systems that are employed by their many departments in the development of a product. Usually, the total corporate data resource is characterized by multi-vendor database servers which, unfortunately, have no ability to relate data from heterogeneous data sources. In this paper, we present a database access interface which allows users to formulate SQL2 queries in a homogeneous way against a federation of heterogeneous databases. The database heterogeneity is not only completely didden from the user, but what the user really perceives is a global database schema which can be queried as though all data reside in a single local database when, in fact, most of the data are distributed over heterogeneous, autonomous, and remote data sources. Further, the users can navigate through the database complex and compare, join, and relate information via a single graphic interface.