Polygon Join Dependencies, Closed Co-relationship Chains and the Connection Trap in Relational Databases

Dependencies in Relational Databases

Induced Dependencies in Relational Databases†

With the growth of database complexity and size it is becoming increasingly necessary to automate the analysis of data. Part of this automation is the development of inductive algorithms to search for characterising rules. The paper introduces the formal concept of an induced dependency as a descriptor for the relationships which characterise the data within a database. This is done within the ...

Cylindric structures and dependencies in relational databases

In this paper, we explore the precise connection between dependencies in relational databases and variants of cylindric algebras, and apply recent algebraic results to problems of axiomatizing dependencies. We will consider project-join dependencies and the corresponding class of cylindric semilattices. We will also look at Cosmadakis (1987) who introduces cylindric dependencies, and makes seve...

Fuzzy Join Dependency in Fuzzy Relational Databases

The join dependency provides the basis for obtaining lossless join decomposition in a classical relational schema. The existence of Join dependency shows that that the tables always represent the correct data after being joined. Since the classical relational databases cannot handle imprecise data, they were extended to fuzzy relational databases so that uncertain, ambiguous, imprecise and part...

Event-Join Optimization in Temporal Relational Databases

An Event-Join combines temporal join and outerjoin properties into a single operation. It is mostly used to group temporal attributes of an entity into a single relation. In this paper, we motivate the need to support the efficient processing of event-joins, and introduce several optimization algorithms, both for a general data organization and for specialized organizations (sorted and append-o...