Although in some cases it is attactive to emulate an IR system through a database, generally an approach that links two independent systems proves to be the more popular choice.
A number of systems have approached the query and data fusion problem between disparate information systems using centrally managed domain knowledge. Systems such as [5] utilize domain knowledge to dispatch queries to the appropriate destination and merge the results. This assumes a formal specification of the properties of different systems.
Researchers at the University of Massachusetts, Amherst have perviously suggested a model for intergrating the INQUERY IR system with an Object Oriented database (OODB) in [10] and with a relation database [42]. Another attempt was also made by a different group [22] to intergrate INQUERY with the Sybase SQL database. All three approaches relied on a specialized query language that was preprocessed by a mediator and submitted to either the IR system or the database. Unfortunately, all three database systems require a pre-defined schema for the database and are not readily extensible. The combination we propose will allow for dynamic shifts in the structure of the database.