Chapter 23 Database Access and Integration

Digital data are now fundamental to all branches of science and engineering; they play a major role in medical research and diagnosis, and underpin business and governmental decision processes. Increasingly these data are organised as shared and structured collections, which are held in databases, in structured documents and in structured assemblies of binary files. The advent of ubiquitous Internet computing and the scale of modern challenges, such as deciphering the function of all the genes in a large number of species, from bacteria to crops, farm animals and humans, has led to widespread collaboration in the creation, curation, publication, management and exploitation of these structured collections. Although individual collections are typically specialised to hold data of interest to particular communities, substantial advances can be achieved by combining information from multiple data resources. For example, astronomers are building virtual observatories, where data collected at different frequencies, X-ray, radio, optical, infrared, etc., and at different times, can be conveniently combined to discover new properties of the universe. Similarly, functional genomics requires comparison between species, integration with protein biochemistry and crystallography databases, laboratory phenotypical data and population studies. Almost every application involves the execution of computational models or computationally demanding analyses using data from diverse sources.