Implementing a distributed database system in the data access layer

Since the first databases were developed, the standard application setup has been a centralized database providing data access to multiple clients. However, decentralized organizations and ever-growing computer networks provide an opportunity and a demand for distributed databases. Modifying existing applications,. designed to work with a centralized database, to work with a distributed database is usually complicated and requires cumbersome changes and thorough verification. This master's thesis describes how an existing data access layer, designed to be used with centralized databases, is extended with a new framework to add support for distributed databases. By placing the changes within the data access layer, changes in existing applications are minimized. The different constraints and requirements of distributed database environments are taken into account in the design of the framework by providing a modular solution