Progress of research into user interfaces to database systems has been slow in comparison to that in other areas of database theory. Whilst interfaces for non-expert access to database systems have been well catered for, little work has been undertaken in allowing end-users to develop their own interfaces. The work in this paper addresses this problem by developing the necessary theory to allow...

One of the characteristics of advanced database systems is that they must handle data which no longer ts the traditional relational style. The present column summarizes recent results on one such extension, where databases handle bags (multisets) rather than just sets. The results illustrate an important research direction in Database Theory. Abstract Most database theory focused on investigati...

We study an approach to relational databases which treats relations not as subsets of a Cartesian product but as subsets of some domain { a partially ordered space of descriptions. This approach permits generalizations of relations that admit null values and variants. In previous work it was shown how to deene the notion of a relation scheme in such a setting. Here we provide a characterization...

metabolomics studies provide useful information about health and disease status. metabolite based investigations on various cancers is a powerful approach to diagnosis, prognosis and therapy of cancer diseases. recently by using advanced analytical techniques such as nmr and ms and its hyphenation methods, global metabolic profiling of diseases has been possible. it is predictable that internat...

More than 20 years of theoretical development and practical experience in the field of Conceptual Information Systems have made available a wide variety of structure and procedures to gain new knowledge from data or to present it in a user-friendly way, by restructuring the data in a conceptual way to help the user interpret and understand the meaning. Even longer, Database Theory has helped de...

abstract scaling methods, which are based on similar media theory, are used to simplify the statistic description of soil spatial variations. to simulate the water flow in heterogeneous soils, simultaneous scaling of soil hydraulic functions, including soil water retention and unsaturated hydraulic conductivity functions, is highly desirable. in the similar media theory, the simultaneous scalin...

Relational databases have had great industrial success in computer science. The power of the paradigm is made clear both by its widespread adoption and by theoretical analysis. Today, automated theorem provers are not able to take advantage of database query engines and therefore do not routinely leverage that source of power. Extensional Reasoning (ER) is an approach to automated theorem provi...

A calculus of typed relations subsuming the classical relational database theory is presented. An associated sound and complete deduction mechanism is developed. The formulation is generalized to deal with nondeterministic databases and information relations in the rough set-style. keywords: relational logic, typed relations, relational database, nondeterministic databases, information relation...

40 { How the folklore heuristics of splitting attributes can be made into a precise design tool for obtaining dependency preserving BCNF. { Why the Embedded Implicational Dependencies are all needed, when we deal with stepwise reenements of database schemes speciied by Functional and Inclusion Dependencies. As the material presented grew slowly while teaching database theory, its foundational a...

The paper presents a novel view of the Dempster-Shafer belief function as a measure of diversity in relational data bases. The Dempster rule of evidence combination corresponds to the join operator of the relational database theory. This rough-set based interpretation is qualitative in nature and can represent a number of belief function operators.