Peter McBrien

Learn More
XML is fast becoming the standard for information exchange on the Internet. As such, information expressed in XML will need to be integrated with existing information systems, which are mostly based on structured data models such as relational, object-oriented or ob-ject/relational data models. This paper shows how our previous framework for integrating(More)
From: Data & Knowledge Engineering Volume 28, Pages 47--71, Elsevier, 1998 Several methodologies for integrating database schemas have been proposed in the literature, using various common data models (CDMs). As part of these methodologies transformations have been defined that map between schemas which are in some sense equivalent. This paper describes a(More)
Data integration is frequently performed between heterogeneous data sources, requiring that not only a schema, but also the data modelling language in which that schema is represented must be transformed between one data source and another. This paper describes an extension to the hypergraph data model (HDM), used in the AutoMed data integration approach,(More)
In: Proceedings of CAiSE2004 Springer-Verlag LNCS c ©2004 Springer-Verlag This paper describes the AutoMed repository and some associated tools, which provide the first implementation of the both as view (BAV) approach to data integration. Apart from being a highly expressive data integration approach, BAV in additional provides a method to support a wide(More)
Although temporal databases have received considerable at tent ion as a topic for research, little work in the area has paid at tent ion t o the concurrency control mechanisms that might be employed in temporal databases. This paper describes how the not ion of the current time also called ‘now’ i n valid-time databases can cause standard serialisation(More)
We review attempts at defining a general extension to the relational algebra to incl udc temporal semantics, and dcfinc two temporal operators to achieve a temporal relational algebra with a close correspondence to temporal logic using since and until. We then dcmonstratc how this temporal relational algebra may IO ;I limited extent be encoded in standard(More)