We suggest a new approach to database updates, in which a database is treated as a collection of theories. We investigate two issues: simultaneous multiple update operations and equivalence of databases under update operations.

α-acyclicity is an important notion in database theory. The α-arboricity of a hypergraphH is the minimum number of α-acyclic hypergraphs that partition the edge set of H. The α-arboricity of the complete 3-uniform hypergraph is determined completely.

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.

Since 90's, database has shown tremendous growth. This growth can be determined in different aspects. Different demands of every era give database a new bunch of challenges. To achieve that challenges, researchers come up with different ideas and combinations. These various combinations enhance features of database and this way database starts evolving from one period to another. Database that ...

Foreword. Category theory is well known as a high-level polymorphic framework suitable for specifying complex structures and formalisms. Quite unexpectedly, however, it turned out that even elementary category theory notions can be valuable in practice of software engineering (see [18, 9, 12]), and in the summer of 1994 we wrote a manifesto ([7], the first version of the present one) to claim o...

A normalization database is considered as mathematics logical design to avoid redundancies and inconsistencies in the stored data which brought about null data and many relationship tables in the physical database. A retrieval rate is affected directly in running a practical system of the normalization design. We argue in the paper that rate formulas given out retrieval speed via testing the va...

We study here the impact of priorities on conflict resolution in inconsistent relational databases. We extend the framework of [1], which is based on the notions of repair and consistent query answer. We propose a set of postulates that an extended framework should satisfy and consider two instantiations of the framework: (locally preferred) l -repairs and (globally preferred) g -repairs. We st...

In spatial database systems rectangles are commonly used to approximate real spatial data. A technique that approximates extended objects with a collection of rectangles is the z-ordering method. Since each of these rectangles eventually corresponds to an entry in a spatial index, the object may be refer-enced several times. This redundancy eeect is controllable. In this paper, we present an em...

Information Fusion is the process of integration and interpretation of heterogeneous data in order to gain new information of higher quality [3]. A successful support for this task requires a tight coupling of different integration and analysis tools: accessing heterogeneous data sources, their integration, preparation and transformation, analysis of syntactic, semantic and temporal structures ...

Database theory and technology has traditionally been concerned with issues such as consistency and efficiency rather than usability. This has led to interaction styles which focus on the structure of the database, which is system-based, rather than the user's view of its content Therefore the problem that needs to be addressed is that of bridging the gap between the user's model of the data an...