An object model for uniform access to heterogeneous databases

The vast amount of patient information collected and maintained by hospitals is seldom stored in a single database. Much programming effort is wasted on formulating specific queries for each of several data sources, rather than focusing attention on developing the intended functionality of the application. This problem becomes more apparent as more data sources become available. The most obvious strategy for dealing with this multiplicity of data sources, namely storing all data in a single database, is impractical for reasons such as security and administrative control. This paper describes one possible solution to managing access to several database systems within applications. Using object-oriented techniques, the solution identifies the commonality among database management systems and provides a uniform method of communication between applications and databases. We describe a C(++)-based implementation which embodies these concepts.