The database theory community, centered around the PODS (Principles of Database Systems) conference has had a long-term interest in logic as a way to represent “data, ” “information,” and “knowledge” (take your pick on the term it boils down to facts or atoms and rules, usually Horn clauses). The approach of this community has been “slow and steady,” preferring to build up carefully from simple...

Dozens of articles have been published describing "new" concurrency control algorithms for distributed database systems. All of these algorithms can be derived and understood using a few basic concepts. We show how to decompose the concurrency control problem into several subproblems, each of which has iust a few known solutions. By appropriately combining known solutions to the subproblems, we...

Consistent answers to a query from an inconsistent database are answers that can be simultaneously retrieved from every possible repair; and repairs are consistent instances that minimally differ from the original instance. Database repairs can be specified as the stable models of a disjunctive logic program. In this paper we show how to use the repair programs to transform the problem of consi...

This study analyzes international strategic alliances in the information industry. The purpose of this study is to clarify the strategic intention of an international alliance. Secondly, it investigates the influence of differences in the target markets of partner companies on alliances. Using an international strategy theory approach to analyze the global strategies of global companies, the st...

From algebraic geometry perspective database relations are succinctly defined as Finite Varieties. After establishing basic framework, we give analytic proof of Heath’s theorem from Database Dependency theory. Next, we leverage Algebra-Geometry dictionary and focus on algebraic counterparts of finite varieties – [polynomial] Ideals. It is well known that intersection and sum of ideals are latti...

The use of computational methodologies for chemical database mining and molecular similarity searching or structure-activity relationship analysis has become an integral part of modern chemical and pharmaceutical research. These types of computational studies fall into the chemoinformatics spectrum and usually have large-scale character. Concepts from information theory such as Shannon entropy ...

Ontology-based data access is an approach to organizing access to a database augmented with a logical theory. In this approach query answering proceeds through a reformulation of a given query into a new one which can be answered without any use of theory. Thus the problem reduces to the standard database setting. However, the size of the query may increase substantially during the reformulatio...

Based on rough set theory many algorithms for rules extraction from data have been proposed. Decision rules can be obtained directly from a database. Some condition values may be unnecessary in a decision rule produced directly from the database. Such values can then be eliminated to create a more comprehensible (minimal) rule. Most of the algorithms that have been proposed to calculate minimal...

We present a soundness theorem for a dependent type theory with context constants with respect to an indexed category of (finite, abstract) simplical complexes. The point of interest for computer science is that this category can be seen to represent tables in a natural way. Thus the category is a model for databases, a single mathematical structure in which all database schemas and instances (...

The aim of this paper is to present a new version of a bibliographic database system Rough Set Database System (RSDS). The RSDS system, among others, includes bibliographic descriptions of publications on rough set theory and its applications. This system is also an experimental environment for research related to the processing of bibliographic data using the domain knowledge and the related i...