Incorporating a virtual union catalogue into the wider information environment through the application of middleware: Interoperability issues in cross‐database access

To explore the use of middleware to provide access to a virtual catalogue via Z39.50, allowing its integration with other services. To consider issues arising from the cross‐database search process and the problem of interoperability between systems.

Middleware was used to establish a Z39.50 server for an existing virtual union catalogue, InforM25. The Copac physical union catalogue was used to carry out cross‐database search tests, investigating the value of query transformation by the middleware and illustrating many of the issues associated with interoperability in cross‐database searching.

The test results demonstrate the viability and benefits of using middleware to allow the integration of virtual catalogues with other services. The results also illustrate the range of issues affecting the performance of the virtual catalogue, with supporting evidence from the use of the Copac physical union catalogue for cross‐database searching via Z39.50. In particular the discussion highlights the issue of semantic interoperability, as well as emphasising the value of centralised virtual catalogue support.

The research was limited to work on a specific virtual union catalogue, that is InforM25, but the results highlight issues with general relevance in the development of any virtual catalogue. The need for more work on response times in the virtual union catalogue is apparent, along with the related issue of result set post processing.

This paper provides a practical demonstration of the issues important to those involved in making their local catalogue accessible to services, and individuals, outside their own institution, as well as those working on virtual union catalogue development.