@phdthesis{Gray2007Integrating-Dis,
Abstract = {  There is an increasing amount of information being made available as data streams, e.g. stock tickers, data from sensor networks, smart homes, monitoring data, etc.
In many cases, this data is generated by distributed sources under the control of many different organisations.
Users would like to seamlessly query such data without prior knowledge of where it is located or how it is published.
This is similar to the problem of integrating data residing in multiple heterogeneous stored data sources.
However, the techniques developed for stored data are not applicable due to the continuous and long-lived nature of queries over data streams.
This thesis proposes an architecture for a stream integration system.
A key feature of the architecture is a republisher component that collects together distributed streams and makes the merged stream available for querying.
A formal model for the system has been developed and is used to generate plans for executing continuous queries which exploit the redundancy introduced by the republishers.
Additionally, due to the long-lived nature of continuous queries, mechanisms for maintaining the plans whenever there is a change in the set of data sources have been developed.
A prototype of the system has been implemented and performance measures made.
The work of this thesis has been motivated by the problem of retrieving monitoring information about Grid resources.
However, the techniques developed are general and can be applied wherever there is a need to publish and query distributed data involving data streams.
},
Address = {Edinburgh, UK},
Author = {Alasdair J.G. Gray},
School = {Heriot-Watt University},
Title = {Integrating Distributed Data Streams},
Url = {http://AlasdairGray.github.io/publications/thesis-final_web-copy.pdf},
Year = {2007},
}