This study develops the foundation for a simple, yet efficient method for uncovering functional and approximate functional dependencies in relational databases. The technique is based upon the mathematical theory of partitions defined over a relation’s row identifiers. Using a levelwise algorithm the minimal non-trivial functional dependencies can be found using computations conducted on intege...

Functional dependencies – traditional, approximate and conditional are of critical importance in relational databases, as they inform us about the relationships between attributes. They are useful in schema normalization, data rectification and source selection. Most of these were however developed in the context of deterministic data. Although uncertain databases have started receiving attenti...

The treatment of many-valued data with FCA has been achieved by means of scaling. This method has some drawbacks, since the size of the resulting formal contexts depends usually on the number of different values that are present in a table, which can be very large. Pattern structures have been proved to deal with many-valued data, offering a viable and sound alternative to scaling in order to r...

The paper presents an axiomatisation for functional dependencies on trees that are defined using constructors for records, lists, sets and multisets. A simple form of restructuring permitting lists to be mapped onto multisets and multisets onto sets is added to the theory. Furthermore, the theory handles dependencies on sets treated as multisets. This adds the possibility to use the count of el...

In this paper we tackle the issue of the automatic recognition of functional dependencies among guessed predicates in constraint problem specifications. Functional dependencies arise frequently in pure declarative specifications, because of the intermediate results that need to be computed in order to express some of the constraints, or due to precise modelling choices, e.g., to provide multipl...

The recent literature has provided a solid theoretical foundation for the use of schema mappings in data-exchange applications. Following this formalization, new algorithms have been developed to generate optimal solutions for mapping scenarios in a highly scalable way, by relying on SQL. However, these algorithms suffer from a serious drawback: they are not able to handle key constraints and f...

The database model CDM intended for modelling design objects is presented. All properties of design objects are modelled by functions. For modelling dynamic dependencies among objects we introduce the notion of dynamic function. The dynamic function comprises capabilities for the description of the object static structure and algorithmic dependencies among objects. Some constraints and practica...

Data integration systems are crucial for applications that need to provide a uniform interface to a set of autonomous and heterogeneous data sources. However, setting up a full data integration system for many application contexts, e.g. web and scientific data management, requires significant human effort which prevents it from being really scalable. In this paper, we propose IFD (Integration b...

A relational database D is given with Ω as the set of attributes. The rows (tuples, data of one individual) are transmitted through a noisy channel. It is supposed that at most one data in a row can be changed by the transmission. We say that A → b (A ⊂ Ω, b ∈ Ω) is an error-correcting functional dependency if the data in A uniquely determine the data in b in spite of the error. We investigate ...