  Schema and data integration have been a challenge for more than 40 years.
While data warehouse technologies are quite a success story, there is still a
lack of information integration methods, especially if the data sources are
based on different data models or do not have a schema. Enterprise Information
Integration has to deal with heterogeneous data sources and requires up-to-date
high-quality information to provide a reliable basis for analysis and decision
making. The paper proposes virtual integration using the Typed Graph Model to
support schema mediation. The integration process first converts the structure
of each source into a typed graph schema, which is then matched to the mediated
schema. Mapping rules define transformations between the schemata to reconcile
semantics. The mapping can be visually validated by experts. It provides
indicators and rules to achieve a consistent schema mapping, which leads to
high data integrity and quality.

Databases