Computer Science Department
School of Computer Science, Carnegie Mellon University
Mediating Among Diverse Data Formats
I have developed a data model and a system of mediator agents that support the widespread use of diverse data formats much more effectively than current approaches do. In this thesis, I describe and evaluate the design and implementation of this data model, known as the Typed Object Model (or TOM), and the system of mediators that supports it. TOM is a read-only object-oriented data model that describes the abstract structure of data formats, their concrete representations, and relations between formats. TOM is supported by a distributed network of mediator agents (known as type brokers) that maintain information about data formats, and provide uniform access to conversions and other operations on those formats. Type brokers plan complex conversion strategies that can involve multiple servers, and ensure that conversions preserve information encoded by clients. Data providers can also register new formats, operations, and conversions with type brokers in a manner, and make them usable anywhere on the Internet. TOM type brokers now work with hundreds of data formats, often through integration of off-the-shelf programs. TOM also supports a wide variety of applications and interfaces, such as the Web-based TOM Conversion Service, that have users worldwide.