Thirty years (and more) of databases

This paper outlines the historical development of data management systems in order to identify the key issues for successful systems. It identifies the need for data independence and the embedding of structural and behavioural semantics in the database as key issues in the development of modern systems. Hierarchical, Network, Relational, Object-oriented and Object-relational data management systems are reviewed. A short summary of related research is given. The paper concludes with some speculation on the future directions that database technology might take.